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Creating a BSP Application You create your Web application in the form of a BSP application. For information about creating BSP applications, see the various tutorials (Creating Web Applications with BSPs) and the documentation on Web Application Builder, specifically the sections under Basic Functions.

Extending Security Aspects with BSP Applications So that a BSP application can function correctly, there must be a node that corresponds to each BSP application in the service tree (Transaction SICF) of the Internet Communication Framework (ICF). From SAP Web AS 6.20, when you create a BSP application in the Web Application Builder, this type of node is created and activated in the appropriate part of the ICF service tree (see also Creating an ICF Service). If necessary, you can add permissions for this node (see also Service Options). For BSP applications that were created before SAP Web AS 6.20 and which therefore do not have any nodes in the ICF service tree, this node is generated automatically by the system as soon as you branch to the corresponding BSP application in change mode.

There may be conflict with old BSP applications with names that are longer than 15 characters. Before SAP Web AS 6.20 you could create BSP applications whose names could exceed the length of the service name in Transaction SICF. In this case, we recommend that you copy all of the old BSP application to a new BSP application with a shorter name, so that the node is automatically created.

BSP Tutorials Purpose To learn how to create Web applications with Business Server Pages, you can work through the simple tutorials that build on each other. You should be able to run through all of the steps described here in your own system.

Advanced

If you want to develop Web applications with BSPs, your system must meet the following requirements: Prerequisites for Creating Web Applications.

The following tutorials are available: 1. • First Tutorial: First Steps with Business Server Pages… 2. •

Second tutorial: A Small BSP Application and A Small BSP Application with

HTMLB

3. •

Third tutorial: Our First Online Bookshop

4. •

Fourth tutorial: Further Developing the Bookshop

5. • A small Tutorial is also available for your first steps with the Model View Controller design pattern. 6. • For a more complex MVC tutorial based on the third tutorial, see: Our Little Online Bookshop Using MVC and HTMLB When creating BSP applications, note the browser dependencies described in Note 598860.

See also: For reference documentation about the BSP programming model, see Business Server Pages.

Getting Started with Business Server Pages Introductory Comments Welcome to the Getting Started tutorial! In this tutorial, you will use SAP Web Application Server to create a basic Web application with the SAP Web Application Server in the form of Business Server Pages (BSPs). This basic application is the basis of all the tutorials, and will be re-used and enhanced as the tutorials progress. This tutorial presents you with a number of topics with sample code, which you can use when creating your own application.

Integration Each tutorial builds on the information presented in the previous one. Below are links to the other tutorials: •

Tutorial 2

•

Tutorial 2 with HTMLB

•

Tutorial 3

•

Tutorial 4

•

MVC Tutorial

•

Our Little Online Bookshop Using MVC and HTMLB

You can also read the reference documentation on the SAP Web AS Architecture, which explains the system’s architecture and components:

Features In this tutorial you will learn how to: •

Create a BSP Application with one page

•

Create HTML code with dynamic script in ABAP

•

Insert a graphic (MIME object)

•

Display the activated page in the Web browser

Let’s get started!

Application Class of a BSP Application Overview A BSP application can include a multitude of different development objects. One of these objects is the application class of the BSP application. The application class is a regular ABAP Objects class. As such, the application class can include any methods, attributes, and events the developers wants. The application class is usually used to store data and make it available across BSP pages. This data is stored as attributes. In addition, the application class encapsulates BSP application logic in methods. This allows several BSP applications to use the same application class and provide one business application that contains different interfaces, such as for various devices, without having to replicate the business or application logic. This also means the global Object application can be used in the BSP application to access the attributes and methods of the application class. You do not have to use an application class in your BSP application. It is an optional way for you to structure your BSP application. You use the Web Application Builder in transaction SE80 to assign an application class to a BSP application.

A simple example of where an application class could be useful would be a class for controlling dialog logic and maintaining data consistency in a BSP application for shopping. This application class would include a shopping basket (internal table or other object) as an attribute. There would also be methods for changing and processing the shopping basket, such as to add, change, or delete articles. Methods for determining prices, creating offers, and posting orders would also be helpful. For an example of the use of an application class, see Extending the Online Bookshop. In many cases, the application class is only used to encapsulate existing application functions, such as from SAP Customer Relationship Management (SAP CRM), and then access the function through BAPI interfaces. Using an application class to encapsulate the functions ensures that the BSP application functions are stored in a central location (in the application class) and that both implementation and distribution are transparent (local method call but remote BAPI call internally). If a customer or developer wants to change or adapt a BSP application or use the application for an additional device, they have the full functions of the original BSP application available in the interface of the application class.

Runtime Behavior Any ABAP Objects class can potentially be used as an application class of a BSP application. However, the BSP runtime environment must treat the class as a singleton, that is, a class for which there is only one instance per session. The lifetime of an application class depends on the state model of the BSP application. A BSP application can be stateful or stateless.

Stateful BSP Application

In Stateful BSP Applications the only instance of the application class, the application object, is generated at the first request sent to the BSP application. The object is then available for the entire lifetime of the session. The end lifetime of the application object ends when the session ends. In stateful mode, the application class provides local buffering for data sets that are difficult to determine.

Stateless BSP Application In Stateless BSP Applications, the application context (roll area) is only available for the lifetime of a single request and is released at the end of the request. When the application context is released, all data and objects held by the session on the application server are also released. This includes the application object. This means the lifetime of the application object starts when the request is received and ends when a response is sent. The application objects is not available across several pages. Each page and each request interacts with a different instance of the application class. In stateless mode, the application object cannot hold data across requests. For stateless applications, application classes are usually used to store the business logic in methods, but do not buffer data.

Accessing the Application Object To access the application object, you use a typed object reference that is stored as the parameter application in all event handlers of a BSP. Of course, you must ensure, however, that the parameter only exists if an application class is defined for a BSP application.

Requirements for an Application Class The only requirement for an application is that the constructor is parameter-less. If not, the application class cannot be generically instantiated by the BSP runtime environment. Otherwise there are no other restrictions. You do need to ensure that the internal implementation of methods is chosen correctly, depending on the state mode where the class is implemented. For stateless applications, for example, it would be useless to implement expensive data gathering routines as these would be lost after every request. Instead, just get the exact data you need at that time. In stateful applications, you can implement an initialization phase where you get a large amount of data at one time, which can improve performance.

Application Events: The IF_BSP_APPLICATION_EVENTS Interface In stateless BSP applications, an application often needs centralized control at certain times in the lifetime of the application. The BSP model provides this function for the application class in the predefined interface IF_BSP_APPLICATION_EVENTS. When an application class implements the optional interface IF_BSP_APPLICATION_EVENTS, the BSP runtime environment calls the interface methods at the relevant times. The following describes the methods and times: IF_BSP_APPLICATION_EVENTS~ON_START

This method is called by the BSP runtime

environment when the corresponding BSP application is first started at the start of the BSP session. This applies to both stateless and stateful applications. Typically, this time point is used to carry out authorization checks that apply to the entire application, or for preliminary data retrieval (in stateful applications). IF_BSP_APPLICATION_EVENTS~ON_STOP

This method is called by the BSP runtime environment when the corresponding BSP application is explicitly ended. This applies to both stateless and stateful applications.

Please note that this time point is not available after every request in stateless BSP applications. In addition this time is not evaluated if the session is implicitly terminated by a timeout. Consequently, in this method it is only possible to execute optional operations that are not critical. Typically, this is a good time for cleanup operations such as deleting browser cookies or server-side cookies, if the application generated them. IF_BSP_APPLICATION_EVENTS~ON_REQUEST

This method is called by the BSP runtime environment for every incoming request to a BSP before the BSP is given control (in the OnRequest event handler). This time can be used by the application class, for example, to restore attributes that were rescued in client- or server-side cookies in a previous request.

IF_BSP_APPLICATION_EVENTS~ON_RESPONSE

This method is called by the BSP runtime for every outgoing response of a BSP after the BSP has been processed (after the OnManipulationevent handler). This time can be used by a stateless application class for tasks such as rescuing attributes in client-side or server-side cookies.

See also: You can find details of interface IF_BSP_APPLICATION_EVENTS in the reference documentation: Interface IF_BSP_APPLICATION_EVENTS

Application Basis Class CL_BSP_APPLICATION If an application class does not already have a super class, it can be derived from the predefined base class CL_BSP_APPLICATION. This class provides methods that are typically required by a BSP application for embedding in a Web environment. This is how information about the current BSP application (such as session timeout, current URL of BSP application, state mode, and so on) can be called or set. As the application object is an application attribute in every BSP event handler, the methods of the CL_BSP_APPLICATION class are also available with the corresponding inheritance. This makes it easy to provide the relevant functionality to lower application levels using a single object reference. See also: You can find details of basis class CL_BSP_APPLICATION in the reference documentation: Class CL_BSP_APPLICATION

BSP Components Business Server Pages (BSPs) are HTML pages that contain the actual application logic and presentation logic. BSPs define the Web user interface and determine the elements of user interaction. BSPs consist of the following components:

Server-side scripting determines the presentation logic as part of layout processing. In the preview, you can check the appearance of your pages, without having to call up the browser. Page attributes are visible in the layout processing as well as in the event handlers of a page. They can be used to store data obtained in the standard handler OnInitialization, and to make this data accessible for the layout processing and the other event handlers. Predefined event handlers are available for the different events. You can use type definitions to define local types. Similar to every object in the SAP System, BSPs also have different administration attributes.

BSP Directives Overview BSP directives are enclosed in tags: <% Directive %> The directives described in the following sections are supported by Business Server Pages (BSP). The syntax is compatible with the familiar server page technology. The following BSP directives are available: • • • • • •

Page Directive Inline Code Comments Include Directive OTR Directives Extension Directive

You use the Tag Library to add BSP directives to your code using Drag & Drop. For more information see Transferring Variables.

Special Programming Features The following code sections for the layout of a BSP are not equivalent: <% read table itab index lv_index. %> <% if sy-subrc ne 0. clear workarea. endif. %> and: <% read table itab index lv_index. if sy-subrc ne 0. clear workarea. endif. %> The first code extract above contains a function module call between the two ABAP commands. The second code extract does not: .... * BSP SCRIPT source read table itab index lv_index.

* BSP STATIC source * HTML begin: #### ###### CALL METHOD %_IF_PM->ADD_STATIC_REF exporting encoding = 0 source = %_HTML_POOL offset = 0000018407 length = 0000000039 . * BSP SCRIPT source if sy-subrc ne 0. clear workarea. endif. .... This means that the sy-subrc set when the internal table is read is overwritten by the function module call. The two pieces of code therefore behave differently.

Page Directive Definition This directive is used to specify the script language. ABAP and JavaScript are currently supported.

<%@ page language=("ABAP" | "JAVASCRIPT") %>

otrTrim From SAP Web AS 6.20 Support Package 7, the attribute otrTrim is also available for the page directive.

<%@ page language=("ABAP" | "JAVASCRIPT") otrTrim=("TRUE" | "FALSE") %> This attribute is a boolean value, that is, it can have the values TRUE and FALSE. The default value is FALSE. If it is set to TRUE, all OTR texts on a page are condensed by removing all blank characters from the start and end of a string. An example of switched on attribute (otrTrim=true): <%@page language="abap" otrTrim="true" %> <% DATA: s TYPE STRING VALUE 'test'. %> [ test line ]
[ before <%= s%> middle <%= s%> end. ]
[<%= otr(sbsp_test/it00_otr_1) %>] The output generated using this coding then looks as follows:

[test line] [before test middle test end.] [This is a test for an alias text]

Example of the case when otrTrim is switched off (otrTrim=false): <%@page language="abap" otrTrim="false" %> <% DATA: s TYPE STRING VALUE 'test'. %> [ test line ]
[ before <%= s%> middle <%= s%> end. ]
[<%= otr(sbsp_test/it00_otr_1) %>] The output generated using this coding then looks as follows: [ test line ] [ before test middle test end. ] [This is a test for an alias text]

Inline Code Definition With this directive you can embed the script code into the page. The inline code is written in the language specified with the Page directive.

<% inline code %>

<%@ page language="javascript"%>… <% inline code javascript %>…

Comments Definition You can write comments on the code on the server. Unlike code that includes HTML comments, server-side comments are not included in the page sent to the client /browser. When you use HTML comments, however, they require longer processing times as well as larger bandwidths. This is why you should not use HTML comments with BSPs or views.

<%-- code comments or text --%>

Include Directive Definition With this directive you can paste in existing pages or pages fragments into the page. Enter the URL of the page to be pasted in relative to the URL of the current page.

<%@ include file="relative URL"%>

OTR Directives Definition The Online Text Repository (OTR) is a repository for all HTML texts, which are accessed using an alias. OTR texts can be translated into other languages using translation tools. At runtime, the OTR directive is replaced by the text defined for the logon language.

Use

There are two ways of using the OTR. 1. You can first write the text in the OTR and give it an alias that should be as meaningful as possible. Then you can display the text with the following syntax: <%=otr(alias)%>. 2. You can however also specify the text in the page layout: HTML text, can also contain scripting code This is an auto-OTR text that is automatically transferred to the OTR and translated there. If the user logs on in a different language, they see the translated text. The text is only automatically transferred if it was entered in the original language. See also: Internationalization and Translation Online Text Repository (OTR)

Extension Directive Definition You can use the extension directive to import a BSP extension into your BSP. As a result you can access all elements of the extension in your BSP. The extension directive is always located immediately after the page directive.

<%@extension name="" prefix=""%> The prefix is used as the namespace for all elements in the BSP extension. The prefixes sap and bsp are reserved. See also: BSP Extensions

Business Server Pages Security Aspects for BSP User Concepts Programming Model What is a BSP Application? Structure of a BSP Application

Accessing a BSP Application Starting and Ending a BSP Application System-Specific URL Parameters Processing a BSP Application Creating a BSP Application Application Class of a BSP Application BSP Components BSP Directives Page Directive Inline Code Comments Include Directive OTR Directives Transferring Variables Extension Directive Classes and Interfaces Global Objects BSP Extensions Model View Controller (MVC) Session Handling Control Flow of BSPs Caching BSPs Page Layout Accessibility Programming Environment SAP Enterprise Portal Administration BSP Tutorials Getting Started with Business Server Pages A Simple BSP Application A Simple BSP Application with HTMLB Online Bookshop Further Developing the Online Bookshop Model View Controller Tutorial Our Little Online Bookshop Using MVC and HTMLB FAQ

Classes and Interfaces The following classes and interfaces are central components of the BSP programming model. Classes: •

Class CL_BSP_APPLICATION

•

Class CL_BSP_MESSAGES

•

Class CL_BSP_SERVER_SIDE_COOKIE

•

Class CL_BSP_GET_TEXT_BY_ALIAS

•

Class CL_BSP_CONTROLLER2

Interfaces: •

Interface IF_BSP_APPLICATION

•

Interface IF_BSP_APPLICATION_EVENTS

•

Interface IF_BSP_NAVIGATION

•

Interface IF_BSP_PAGE

•

Interface IF_BSP_RUNTIME

•

Interface IF_BSP_PAGE_CONTEXT

•

Interface IF_HTMLB_TABLEVIEW_ITERATOR

Many of these classes and interfaces are the basis for their associated global objects. To develop BSP applications with the focus on representing Web pages on different mobile end devices, you can use interface IF_CLIENT_INFO.

Global Objects Certain global objects can be accessed from all parts of a BSP (initialization, layout, input processing). For example, the request and response object, the application object (if an application class was defined for the BSP application), the navigation object, and the runtime object, can be accessed. The following global objects are available: • • • • • • • •

Object application Object navigation Object messages Object runtime Object request Object response Object page Object page context

This is described in more detail below. The objects and their signatures for the individual event handlers are displayed if you choose Example:

in the Web Application Builder.

Class CL_BSP_APPLICATION Overview Class CL_BSP_APPLICATION is an optional superclass for BSP application classes. Each application has the option of deriving its own application class from CL_BSP_APPLICATION . If the application class has not already been derived in an inheritance hierarchy, we recommend that it is derived from CL_BSP_APPLICATION . Class CL_BSP_APPLICATION has methods that are typically required by a BSP application for embedding in a Web environment. This is how information about the current BSP application (such as session timeout, current URL of BSP application, state mode and so on) can be called or set.

All of the methods of class CL_BSP_APPLICATION can be accessed via the interface IF_BSP_APPLICATION and are described in the corresponding reference documentation. See Also: • •

IF_BSP_APPLICATION Object application

Class CL_BSP_MESSAGES Overview You can use class CL_BSP_MESSAGES in BSPs for outputting error and information messages. You can flag each message with a condition that serves as a key for the message. The effect of this is that a message is only output in a BSP if the pertinent condition is fulfilled. This makes it easy to place input-specific messages directly beside the relevant input fields. Each BSP has an instance of this class that contains the current messages of the class. The object is reset after every HTTP request/response cycle. The object is accessed from a BSP via the parameter page of the event handler as page->messages or via the self-reference me in the form of interface qualification me->if_bsp_page~messages.

Inheritance Hierarchy/Interface Composition Implemented Interface -

Superclass -

Attributes Attribute Name

Declaration Type

Description

co_severity_error

Constants

Error severity: error

co_severity_fatal_error

Constants

Error severity: Fatal error

co_severity_info

Constants

Error severity: Information

co_severity_success

Constants

Error severity: Confirmation of success

co_severity_warning

Constants

Error severity: Warning

Methods Method add_message Signature

method add_message importing condition type string message type string optional otr_alias type string optional

severity type i default co_severity_error . Description

This method inserts the message on the condition specified into the list of messages. If there is already a message with the condition, it is overwritten. One of the two parameters message or otr_alias must be specified (exclusive or). If message is used, the message text is transferred directly, if otr_alias is used, the alias name of an OTR text is transferred. This makes it easy to address language-dependent messages from the OTR.

Parameters

CONDITION

Message condition

MESSAGE

Message text (if otr_alias-parameter is not used)

OTR_ALIAS

Alias name of an OTR text to be used as message text (if message parameter is not used)

SEVERITY

Message severity (see constants co_severity_...)

Return Values/Exceptions

-

Cross References

See also: assert, assert_message, assert_severity

Method assert Signature

method assert importing condition type string returning index type i .

Description

This method returns the message index (1..n) for the condition specified or 0 if there is no message for this condition. Thus, you can use this method in BSPs in if statements if, for example, you want to insert HTML areas in the output on a message-

dependent basis. Example: ... <% if page->messages->assert( 'invaliduser' ) <> 0. %> <%= page->messages->assert_message( 'invaliduser' ) %> <% endif %> … Parameters

CONDITION

Message condition

Return Values/Exceptions

INDEX

=0: no message for condition >0: Message index

Cross References

See also: assert_message, assert_severity

Method assert_message Signature

method assert_message importing condition type string returning message type string .

Description

This method returns the message for a specified condition. If there is no message for the condition, it returns an empty string.

Parameters

CONDITION

Message condition

Return Values/Exceptions

MESSAGE

Message

Cross References

See also: assert, assert_severity

Method assert_severity Signature

method assert_severity importing condition type string returning severity type i .

Description

This method returns the message severity (see

constants co_severity_... ) for the specified condition, or 0 if there is no message for the condition. Parameters

CONDITION

Message condition

Return Values/Exceptions

SEVERITY

=0: no message for condition >0: Message severity (see constants co_severity_...)

Cross References

See also: assert, assert_message

Method get_message Signature

method get_message importing index type I exporting severity type I condition type string message type string .

Description

This method returns information about the message for the specified index (1..n). If there is no message for the index, in other words, if index > num_messages(), this is indicated by severity = 0 .

Parameters

INDEX

Message index (1..num_messages())

Return Values/Exceptions

message

Message text

condition

Message condition

severity

Message severity (see constants co_severity_...)

Cross References

See also: add_message, num_messages

Method num_messages Signature

method num_messages returning count type I .

Description

This method returns the number of messages

that were defined using add_message(). Parameters

-

Return Values/Exceptions

count

Cross References

See also: add_message

Number of currently existing messages

Class CL_BSP_SERVER_SIDE_COOKIE Overview Class CL_BSP_SERVER_SIDE_COOKIE provides methods for setting, getting, deleting, and managing cookies on the server. Server-side cookies are persistent data, similar to the usual client-side cookies. However, while on the client-side, there are restrictions that limit the size of cookies to around 4 kilobytes per cookie, the number of cookies to 300 in total and 20 per server or domain, server-side cookies are subject to no such restrictions. A server-side cookie is stored on the database. For technical reasons, each individual cookie can be stored in one of the following ways: • • •

as a field or as a structure or as an internal table

When you get a cookie, please note that it must be returned to the same data structure. Otherwise, an error will occur, which you can query using an error method. The parameters username and session_id deserve special attention. Setting username to sy-user is ambiguous in cases where an application is started by an anonymous user stored on the server. It would be better to use session_id (see example) since runtime>session_id indicates the browser session. When you design an application, you should give careful consideration to whether the application should be stateless and the required context data be retained from page to page in cookies (client-side or server-side), or whether the application should be stateful. A stateful application makes sense when there is a large amount of context data that would otherwise have to be read from or written to the database using cookies and thus slow down performance (see also Stateful or stateless programming?). The program BSP_SHOW_SERVER_COOKIES provides an overview of all of the cookies set in the system. The program BSP_CLEAN_UP_SERVER_COOKIES deletes all expired cookies to the day.

The system administrator should schedule the program BSP_CLEAN_UP_SERVER_COOKIES to run in the background on a regular basis. Class CL_BSP_SERVER_SIDE_COOKIE is contained in the package SBSP_RUNTIME.

Inheritance Hierarchy/Interface Composition Implemented Interface -

Superclass -

Attributes Attribute Name

Declaration Type

Description

CC_OK

Constants

Action was successful.

CC_WRONG_DATA_OBJECT

Constants

The data object of the cookie to be read does not match the data object of the set cookie.

CC_PARAMETER_MISSING

Constants

Call parameters are missing.

CC_NOT_EXISTS

Constants

Cookie does not exist.

Methods All of the methods are in the visibility section public section.

Method get_server_cookie Signature

method GET_SERVER_COOKIE exporting NAME EXPIRY_TIME EXPIRY_DATE SESSION_ID USERNAME APPLICATION_NAMESPACE APPLICATION_NAME DATA_NAME DATA_VALUE

Description

This method gets a server cookie.

Parameters

EXPIRY_TIME

Validity date (time): to time

EXPIRY_DATE

Validity date (date): to date

DATA_NAME

Data object name

SESSION_ID

Session ID

USERNAME

Name of user

APPLICATION_NAMESPACE

Name space of BSP application

APPLICATION_NAME

Name of BSP application

NAME

Name of cookie

DATA_VALUE

Data object content

data: sorders type sales_orders, edate type d, etime type t, usr type string. clear sorders. call method cl_bsp_server_side_cookie=>get_server_cookie exporting name = 'SALESORDER_GETLIST' application_namespace = runtime>application_namespace application_name = runtime->application_name username = usr session_id = runtime->session_id data_name = 'SORDERS' importing expiry_date = edate expiry_time = etime changing data_value = sorders.

Method delete_server_cookie Signature

method DELETE_SERVER_COOKIE exporting NAME APPLICATION_NAME APPLICATION_NAMESPACE USERNAME SESSION_ID

Description

This method deletes a server cookie.

Parameters

NAME

Name of cookie

APPLICATION_NAME

Name of BSP application

APPLICATION_NAMESPACE

Name space of BSP application

USERNAME

Name of user

SESSION_ID

Session ID

data: usr type string. call method cl_bsp_server_side_cookie=>delete_server_cookie exporting       name = 'SALESORDER_GETLIST'       application_namespace = runtime>application_namespace       application_name = runtime->application_name       username = usr       session_id = runtime->session_id.

Method set_server_cookie Signature

method SET_SERVER_COOKIE   importing     DATA_VALUE   exporting     EXPIRY_DATE_ABS     EXPIRY_TIME_ABS     DATA_NAME     SESSION_ID     USERNAME     EXPIRY_TIME_REL     EXPIRY_DATE_REL     APPLICATION_NAMESPACE     APPLICATION_NAME     NAME

Description

This method sets a server cookie.

Parameters

DATA_VALUE

Data object content

EXPIRY_DATE_ABS

Valid to date

EXPIRY_TIME_ABS

Absolute validity duration

If you do not specify a value, the system sets the absolute validity duration to 23.59. DATA_NAME

Data object name

SESSION_ID

Session ID if required

USERNAME

Name of user, and email address

EXPIRY_TIME_REL

Relative validity duration in seconds

If you do not specify a value, the system sets the relative validity duration to 23.59. EXPIRY_DATE_REL

Validity duration in days

APPLICATION_NAMESPACE

Name space of BSP application

APPLICATION_NAME

Name of BSP application

NAME

Name of cookie

data: sorders type sales_orders,       edate type d,       usr type string. call function 'BAPI_SALESORDER_GETLIST' destination 'ABC'   exporting     customer_number = '0000001000'   tables     sales_orders = sorders.

edate = sy-date. add 1 to edate.   "valid for one day call method cl_bsp_server_side_cookie=>set_server_cookie   exporting     name = 'SALESORDER_GETLIST'     application_namespace = runtime>application_namespace     application_name = runtime->application_name     username = usr     session_id = runtime->session_id     expiry_date_abs = edate     expiry_time_abs = sy-uzeit     data_name = 'SORDERS'     data_value = sorders.

Method get_last_error Signature

method GET_LAST_ERROR   importing     RC

Description

This method returns the return code of the last call.

Parameters

RC

Returncode

data: rc type i,       txt type string. rc = cl_bsp_server_side_cookie=>get_last_error( ).

Method get_last_error_name Signature

method GET_LAST_ERROR_NAME   importing     NAME

Description

This method returns the internal name of the exception of the last call.

Parameters

NAME

Internal error text

data: rc type i,       txt type string. rc = cl_bsp_server_side_cookie=>get_last_error( ). if rc ne 0.   txt = cl_bsp_server_side_cookie=>get_last_error_name( ). endif.

Method get_server_cookie_info Signature

method GET_SERVER_COOKIE_INFO   exporting     COOKIES     APPLICATION_NAMESPACE     APPLICATION_NAME

    SESSION_ID     USERNAME     NAME Description

This method returns information about server cookies.

Parameters

COOCIES

List of all cookies.

APPLICATION_NAMESPACE

Name space of BSP application

SESSION_ID

Session ID

USERNAME

Name of user

NAME

Name of cookie

APPLICATION_NAME

Name of BSP application

data: usr type string,       cookie_info type tsscookiei. call method cl_bsp_server_side_cookie=>get_server_cookie_info   exporting     application_name = runtime->application_name     username = usr   importing     cookies = cookie_info .

Class CL_BSP_GET_TEXT_BY_ALIAS Overview Class CL_BSP_GET_TEXT_BY_ALIAS provides a method to fetch OTR alias texts.

Inheritance Hierarchy/Interface Composition Implemented Interface -

Superclass -

Attributes -

Methods Method GET_TEXT Signature

method GET_TEXT importing LANGUAGE ALIAS returning ALIAS_TEXT.

Description

This method fetches an OTR alias text for a specified OTR alias name.

Parameters

LANGUAGE

Current language of SAP System

ALIAS

Name of alias in form ’<Paket>/’

ALIAS_TEXT

Text of the alias

Cross References

See also: Internationalization and Translation Method GET_OTR_TEXT of IF_BSP_RUNTIME

report OTRTEST. class CL_BSP_RUNTIME definition load. data TEXT type STRING. TEXT = CL_BSP_RUNTIME=>GET_OTR_TEXT( ALIAS = 'sbsp_test/it00_otr_1' ). write / TEXT.

Class CL_BSP_CONTROLLER2 Overview Class CL_BSP_CONTROLLER2 is used to create controllers and components. Every controller class automatically inherits all methods and attributes from this central basic class.

If the basic class of your controller class displays CL_BSP_CONTROLLER instead of CL_BSP_CONTROLLER2, change the inheritance hierarchy accordingly. Class CL_BSP_CONTROLLER2 enables you to: • • • •

Retain a list of sub-controllers Create unique IDs for the sub-controllers, where the sub-controller is assigned the controller ID prefix Use models Forward data to the correct controller as well as fill model classes (if they exist)

Methods Below you can find an overview of all methods in a controller class. Processing Process provides details on the most important methods. The individual methods can be separated into different categories:

Functions where overwriting is required DO_REQUEST is the central method in a controller class. You must overwrite this method. In DO_REQUEST you specify the request processing, that is, this method is called for every request. This method does the "main work"; in particular it should branch to the correct view. DO_REQUEST can be used in two different areas: •

If it is the top-level controller of a component, then this method handles both input and output processing.

•

If it is a sub-controller of a component, then this method only handles output processing.

Functions where overwriting is recommended You should overwrite these methods in order to determine input processing. Method

Description

DO_HANDLE_DATA

Reacts to user input. Processes data input for this component.

DO_HANDLE_EVENT

Reacts to user input. Processes events if the component contains them. Exactly one view controller is called to handle the event, which contains an event such as a save button, for example.

DO_FINISH_INPUT

Ends the input processing.

Functions where overwriting is possible You can overwrite these methods in order to determine input processing. Method

Description

DO_INIT

This method is called once at the start and is used for initialization. This method behaves like a constructor method.

DO_INITATTRIBUTES

This method is called with every request and is used to initialize the attributes. The parameters are read from the request. In this method, you can also execute initializations that are required for each request. You can also use this method to set additional attributes. This method is not absolutely necessary, since you can use DO_REQUEST to solve everything that you can (theoretically) handle here.

Service functions You can call these methods: Method

Description

CREATE_VIEW

Creates or fetches a view instance Use either the name of the view, or the navigation.

object

A view must always belong to the same BSP application as its controller. CALL_VIEW

Calls the request handler of the view instance.

CREATE_CONTROLLER

Creates or fetches a controller instance

CALL_CONTROLLER

Calls the request handler (method DO-REQUEST) of the controller instance.

GET_ATTRIBUTE

Returns the specified page attributes. Generic method for reading an attribute value.

GET_LIFETIME

Returns the lifetime of this page (only for the top-level controller)

GET_PAGE_URL

Returns the URL of the page or the current controller

SET_ATTRIBUTE

Sets the specified page attributes. Generic method for setting an attribute value.

SET_LIFETIME

Changes the lifetime of this page (only for the toplevel controller)

TO_STRING

Creates a formatted string

WRITE

Writes a formatted string in the output

GET_OUT

Fetches the current output writer

SET_MIME_TYPE

Changes the MIME type of the page or the content type of the header field

INSTANTIATE_PARAMETER

Instantiates the parameter from the request using the request data

SET_CACHING

Changes the caching values There are two types of caching: •

Browser cache

•

Server cache

See also

Caching BSPs.

You can only use limited caching here. Note that the server cache is not user-specific. If you change the page, you should reset the cache that may be set. DISPATCH_INPUT

Dispatches the input processing (only for the top-level controller). For each input, DISPATCH_INPUT calls the correct methods in the correct sequence. This method fetches data from the request. This method does not have any attributes.

GET_ID

Calculates the ID from the specified ID and the component ID

SET_MODEL

Creates and registers a model instance

CREATE_MODEL

Creates and registers a model instance

GET_CONTROLLER

Fetches a sub-controller

CONTROLLER_SET_ACTIVE

Sets a controller to active/inactive. This is relevant with input processing, since you can use it to hide a controller. See also Lifetime

DELETE_MODEL

Deletes a model instance

FILL_MODEL_DATA

Fills the model data

DELETE_CONTROLLER

Deletes a sub-controller

GET_MODEL

Fetches a model instance

IS_TOPLEVEL

Is this controller a top (main) controller (0: no, 1: yes)?

IS_NAVIGATION_REQUESTED

Has a controller requested a navigation (0: no, 1: yes)?

Framework functions These methods are provided as part of the framework and are only included here for the sake of completeness. They are not usually relevant for application development. Method

Description

IF_BSP_DISPATCHER~REGISTER

Registers a sub-components

IF_BSP_CONTROLLER~FINISH_INPUT_PROCESSING

Processes or dispatches: end of input processing.

IF_BSP_CONTROLLER~FILL_VALUES

Processes or dispatches: handling values

IF_BSP_CONTROLLER~HANDLE_EVENT

Processes or dispatches: Handle event

GET_FIELD_COMPONENT

Finds components for a field name

GET_FIELD_MODEL

Finds model for a field name

Methods DO_DESTROY and SUBSCRIBE are not relevant.

Examples of Architecture Previous BSP Application With SAP Web AS 6.10, normal BSP applications usually consisted of an application class and several BSPs. Navigation between the pages was controlled using redirects.

This is how it looks with SAP Web AS 6.20: BSP Application with Controllers and Views

Model View Controller Tutorial Uses In this tutorial you can use a simple example to run through the first steps with the View Controller design pattern for BSP.

Model

The general bookshop tutorial for BSP contains a more extensive MCV tutorial: Our Online Bookshop Using MVC and HTMLB.

Prerequisites • •

You are in an SAP Web AS 6.20 system You know how to use MVC for BSPs

Functions Creating a Controller Creating a View Calling a Controller

Creating a Controller Prerequisites You have created an empty BSP application for this tutorial.

Procedure 1. Create a controller within your BSP application. To do this, choose Create → Controller.

2. On the following dialog box, give the controller a name and add a short description.

3. Choose

. 4. On the following screen, assign a class name to the controller. The class does not have to exist yet.

5. You navigate to the Class Builder by double-clicking on the controller class. If the class does not already exist, the system asks you if you want to create it. Choose Yes so that you create a class with the specified name that is derived from CL_BSP_CONTROLLER2.

Each controller class must be derived directly or indirectly from CL_BSP_CONTROLLER2.

6. Choose the 7.

symbol to branch to the change mode in your class.

Select method DO_REQUEST and choose symbol

to overwrite the methods.

8. Generate the required output. In this example, it is simple HTML: method DO_REQUEST . write( '

' ). write( 'This is my very first controller' ). write( '

' ). endmethod. 9. Activate your class and your BSP application. 10. Before you can test the controller, in Transaction SICF you must also activate the new entry that was automatically created for your BSP application (see also Activating and Deactivating an ICF Service).

In Transaction SICF, select the entry for your BSP application and choose Service/Virt.Host → Activate.

Confirm the following confirmation prompts. 11. You can now test the new controller page that you have created.

Result

Continue by creating a view.

Creating a View Use If you do not always want to use the write function to create the HTML page content (as described in Creating a Controller), and you want to create it as pure HTMLO layout instead, then create a view that you can call from the controller.

Procedure ...

1.

Begin as if you are creating a normal page with flow logic in your BSP application.

To do this, choose Create → Page.

2. In the following dialog box, enter a name and short description of the view and select View as the page type:

3. 4.

Choose . Create the attributes for the variable parts of the view.

You cannot define auto-page attributes, since views cannot be called directly from the browser.

Create the following attribute:

5.

Define the layout as usual:

<%@ page language="abap" %>

View Example

Hello, user <%= name%>

6. 7.

Activate the view. Finally, adjust the DO_REQUEST method to the controller class.

Here, the schema is always the same. First you create the view, then you set the attributes, and then you call the view. (For the time being you can ignore the warning concerning exception CX_STATIC_CHECK, or you can set a try-catch block around the calls):

method DO_REQUEST . data: myview type ref to if_bsp_page. myview = create_view( view_name = 'view_test.htm' ). myview->set_attribute( name = 'name' value = sy-uname ). call_view( main_view ). endmethod. 8.

Activate your class and test your controller.

Result You have created your own view for the layout.

Continue by Calling the Controller.

Creating a View Use If you do not always want to use the write function to create the HTML page content (as described in Creating a Controller), and you want to create it as pure HTMLO layout instead, then create a view that you can call from the controller.

Procedure ...

1.

Begin as if you are creating a normal page with flow logic in your BSP application.

To do this, choose Create → Page.

2. In the following dialog box, enter a name and short description of the view and select View as the page type:

3. 4.

Choose . Create the attributes for the variable parts of the view.

You cannot define auto-page attributes, since views cannot be called directly from the browser. Create the following attribute:

5.

Define the layout as usual:

<%@ page language="abap" %>
href="../../sap/public/bc/bsp/styles/sapbsp.css">

View Example

Hello, user <%= name%>

6. 7.

Activate the view. Finally, adjust the DO_REQUEST method to the controller class.

Here, the schema is always the same. First you create the view, then you set the attributes, and then you call the view. (For the time being you can ignore the warning concerning exception CX_STATIC_CHECK, or you can set a try-catch block around the calls):

method DO_REQUEST . data: myview type ref to if_bsp_page. myview = create_view( view_name = 'view_test.htm' ). myview->set_attribute( name = 'name' value = sy-uname ). call_view( main_view ). endmethod. 8.

Activate your class and test your controller.

Result You have created your own view for the layout.

Continue by Calling the Controller.

Calling a Controller Use You can call a controller from a page with flow logic, or from a view.

Procedure 1. Create a page within your BSP application. Ensure that you select Page with Flow Logic as the page type.

2. In the Tag Browser, select BSP extension bsp and drag it to the second line of your BSP’s layout under the page directive.

3. Now drag the directive of BSP extension bsp to the body of the HTML layout and add the URL parameter. The source now looks as follows: <%@page language="abap"%> <%@ extension name="bsp" prefix="bsp" %> 4. You can now activate and test the page. The page looks as follows:

Ensure that the page you have tested looks exactly the same as when you tested the controller. The URL is different, however. You can use View Source in the browser to see that nothing remains of the HTML text from the BSP, but that only the content of the view is displayed:

View Example

Hello, User GREBEL

5. You can now try out the difference between the element and the element.

If you use the element instead of the element, the calling page text remains the same. In the view that is inserted, you should therefore delete the HTML text available on the outline page, otherwise these texts will be transferred twice.

6. You can add another attribute to the controller. This is a public class attribute. It is set using the element. You can use it for example to control which view is called, or this value can be passed to the view.

Online Bookshop The BSP application that you create in these tutorials is an online bookshop. The first page (entry page) of the bookshop should look like this:

In this application you will learn to create BSPs as page fragments and to include them in other BSPs using include statements. This ensures that all the headers in your BSPs are identical. You will also learn to work with ABAP methods for data retrieval. The methods used here are part of the package SBOOKSHOP, which is described in the section Data Model. You can do the following from the first page: • • •

Go to the catalog from the second tutorial Search for a book Call up information about the bookshop

To go to the catalog, choose the link catalog (from last tutorial):

This takes you to the list of authors from the second tutorial:

To search for a book, the user chooses the link search book:

On the following page, criteria can be specified:

If the user searches for the author "Keller", the results list shown below appears. Note that this search is an OR search. The user can also search by title, publisher, keyword, or ISBN number. If the user enters an invalid ISBN number, an error message appears.

To get detailed information on a book, click on the book title:

You can now choose For general information about this tutorial, choose about.

The following information page appears:

to order this book.

The method for processing this BSP application is described in section Processing Procedure. For information on the data model in the SAP System, see the section Data Structures. For background information about the structure and functions of BSP Applications see What Is a BSP Application?.

Go to Processing Procedure, to Data Structures, or to Creating BSP Applications and Pages.

Processing Process The internal structure illustrated below underlies the BSP application with the interface just described:

The arrows represent navigation paths between the pages. For information on the data model in the SAP System, see section Data Structures. For information on "clean" and efficient programming, see the section Separation of Data Retrieval, Evaluation, and Output.

Now you can get started with creating your BSP application.

Get started!

Separation of Data Retrieval, Evaluation, and Output

To give the BSP application a clear and transparent structure, it makes sense to store logical and functional elements in Event Handlers (these contain only program code). In the HTMLbased layout part, dynamic scripting code should only be used to display data on the page in question. In this tutorial, the book search facility demonstrates the advantages of clearly separating data retrieval, evaluation, and output: •

The page attributes for the results page are set in the OnInputProcessing of the search page. If nothing was input, the results page should not be opened.

•

In the initialization part (OnInitialization) of the results page results.htm, the method search_book is called to search for book titles that match the criteria entered. If an invalid ISBN is entered, the page invalid_isbn.htm opens. If another type of error occurs, the error page opens. If no errors occur, the titles of the books found are written to the internal table bookcat_tab.

•

The layout part, then, simply checks whether or not this table is empty. If it is empty, this means that no matching entries were found. If the table is not empty, the results are output in a HTML table.

This ensures that functionality and logic (error handling) are kept out of the layout part.

Data Model for the Bookshop Tutorials The data model described here in the basis of the bookshop tutorials. In the package SBOOKSHOP in your system, you will find the following database tables and other objects used in the tutorials. Only the most important objects are listed here. For a complete list, see the Object Navigator in your system.

Database Tables SBOOKSHOP contains the following database tables: Table Name

Key Fields

Other Fields

Meaning

BSAUTHORS

MANDT

AUTHFNAM

ISBN

AUTHLNAM

In addition to the client for each book, this table also contains the ISBN and the first and last names of the author, written once in standard case and once in upper case.

AUTHFNAME AUTHLNAME BSBOOK

MANDT

TITLE

ISBN

SUBTITLE

This table contains the titles of the books available in the bookshop. ISBN and client are the

SERIES PUBLISHER PUBLYEAR BOOKPAGES

key fields. The other fields are title, sub-title, book series, publisher, year of publication, number of pages, the recommended retail price, the currency (euro), and the country code.

PRICE_RAW CURRENCY COUNTRY BSCATALOG

MANDT

CURRENCY

CATA_ID

OUR_PRICE

ISBN

DELIVERY COVER_URL

This table represents the book catalog. Each book has a unique number, the CATA_ID. The CATA_ID and the ISBN number are the key fields for this table. The other fields are currency (euro), price in our shop, expected delivery time, and the URL of a picture of the book cover.

BSCUSTOMER

MANDT

TITLE

CUSTOMERID

SURNAME FIRSTNAME COMPANY STREET ZIP CITY COUNTRY DISCOUNT

This is the customer table. All customer data is stored here. The customer’s e-mail address (this must be unique) and the client are used as the key field. The other fields are title, first name and surname of the customer, customer address (street, postcode, city, and country), details of any discount arrangement with the customer, and the customer’s password.

USRPWD BSKEYWORD

MANDT

In addition to the client this table contains a keyword for an ISBN.

ISBN KEYWORD BSORDER

MANDT

ORDERDATE

CUSTOMER

AMOUNT

ORDER_ID

STATUS

ISBN

BSTEXTS

MANDT

ISBN

RELID

TEXT_TYPE

SRTFD

REVIEW_NO

SRTF2

INPUTDATE CLUSTR CLUSTD

This table contains all the orders. The key fields are the client, the customer ID (that is, the e-mail address), the order ID (assigned when the order is placed), and the ISBN. Other fields are the date of the order, the number of books ordered, and the order status. This is the table for long texts in the bookshop. The key fields are the client, the area in the import/export data table, the user-defined key part of the table INDX, and the next record counter in the import/export data table. The other fields are ISBN, the type of a long text in the bookshop, an internal field, the date, a field length for user data, and a database field for the IMPORT/EXPORT tables.

Classes and Methods The bookshop has the class CL_BOOK_SHOP. This class includes the following methods: Method

Parameter

SEARCH_BOOK

Description Book search

TITLE

Book title

AUTHOR

Surname of author

PUBLISHER

Publisher

KEYWORD

Key words

ISBN

ISBN

ISBN_TAB

Table of ISBNs

GET_BOOK_DATA

Reading the book table ISBN_TAB

Table of ISBNs

BOOKCAT_TAB

Table of books

MAINTENANCE_SCREEN

Input and output of book data on the screen NEW_ENTRY

Indicator

ISBN

ISBN

GET_ITEM

Reading a catalog entry CAT_ID

Bookshop index

BOOK_DATA

Structure for transferring all relevant data for a book

CHECK_ISBN

Symbol

ISBN check ISBN

ISBN

Flag

Indicator Meaning Import parameter Export parameter Return parameter

Creating Page Fragments

Use Page fragments help ensure that the appearance of your Web application is consistent. Similarly to frames, you can use page fragments to implement the same layout for different parts of your page. In this tutorial, you will use a page fragment to implement a consistent header for all BSPs in your BSP application. You simply include the page fragment in all your BSPs.

Procedure Take the following steps to create a page fragment for your BSP application:

1. In the Web Application Builder, open your application (tutorial_3), position your 2.

cursor on the highest-level hierarchy node in the left-hand navigation tree, and, using the right mouse button, choose Create → Page . In the popup that appears, enter a meaningful name (the system will propose the extension .htm) and a description, and select the page type Page Fragment.

3. Choose . 4. Create the code for your page fragment. <%@ page language="abap" %>

  mySAP Bookshop

---

5.

6. Make sure that you do not include the end tags and in this code, as this is a page fragment, and page fragments are always located at the beginning of the HTML page. Correspondingly, page that include the fragment head.htm have no start tags, only end tags. 7. This ensures that the headers that are included in every BSP by means of the steps outlined below always look the same:

8. 9. This also sets the background color for the whole page. 10. Choose .

Result In the Web Application Builder your entire BSP application with the pages, images, and page fragment are displayed:

Layout for the First Page

Layout for the First Page The layout for the first page (default.htm), which you set using the tab page Layout, looks like this: <%@ page language="abap" %> <%@ include file="head.htm" %>

Welcome to our small bookshop!

It offers the following small features:

catalogue (from last tutorial)

search book

about
This code uses HTML to create three links, and uses the include directive (see below). The first link links to the list of authors, which you created in the previous tutorial (see A Simple BSP Application). The second link links to the search page, and the third link links to an information page.

The Include Directive In the code for this page, the following line comes after the page directive: <%@ include file="head.htm" %> This directive includes the page fragment head.htm in the page default.htm. This has the effect that the first page gets the header defined in head.htm.

The syntax of the page directive is as follows: <%@ include file="relative URL" %> The include directive includes existing pages and page fragments in the BSP. Make sure that you always use a relative URL when specifying the page to be included.

If you view the page default.htm in the browser and choose View Source, you will see that the HTML code simply consists of head.htm and default.htm.

Layout for the Info Page

Layout for the Info Page The layout for the information page about.htm, which you set using the tab page Layout, looks like this: <%@ page language="abap" %> <%@ include file="head.htm" %>

Demo bookshop for BSP tutorial

© by SAP AG 2000.

The page fragment head.htm is also included in this page.

Layout for the Search Page

Layout for the Results Page The layout for the page results.htm, which you set using the tab page Layout, looks like this: <%@ page language="abap" %> <%@ include file="head.htm" %> <% IF bookcat_tab IS INITIAL. %> No books were found to match your query.

Go back to the search form <% ELSE. %>

<% DATA bookcat TYPE bsbookdata. LOOP AT bookcat_tab INTO bookcat. %>

<% ENDLOOP. %>

Title	Author(s)	Delivery	Our Price
"> <%= bookcat-title %> <small><%= bookcat-subtitle %>	<small><% DATA author_wa TYPE bsauthors. LOOP AT bookcat-authors INTO author_wa. %> <%=author_wa-authfname %> <%=author_wa-authlname %> <% ENDLOOP. %>	<%= bookcat-delivery %>	<%= bookcat-our_price %><%= bookcat-catal_curr %>

<% ENDIF. %> The page fragment head.htm is also included in this page. First, this code checks whether there are any entries in the structure bookcat_tab that match the search criteria. If there are not, an error message is output. The user can then click on a link on the error page to return to the search page. If there are matching entries in the bookcat_tab structure, the results are output in a fourcolumn table. The output is then processed in detail: A loop statement writes the content of the internal table bookcat_tab line by line into a help variable. When this happens, the title and sub-title for each book are stored along with a link. The variable ?s_cata_id is included in the link after the page details. "> Next, the first name and surname of the author, the delivery time, and the price are retrieved, and all this data is written to the table. The variable s_cata_id contains the unique ID number of a book in the catalog. This ID number is the primary key of the database table bscatalog in the SAP System (see Data Model).

Attributes for the Results Page

Page Attributes for the Results Page Use the tab page Page Attributes to define the required page attributes for the results page (results.htm).

These attributes are the fields that are used to search on the search page. They also correspond to the import parameters of the method search_book in the SAP System (see also Data Model). These attributes are flagged as automatic, as they were set using navigation->set_parameter on the search page, and now variables of the same name are being used again. There is also the page attribute bookcat_tab. This is the table in the Data Dictionary that contains the book and catalog data for the tutorials. This table is not flagged as an automatic page attribute, as it is being used for the first time.

Auto page attributes can have various data types, structures or tables but no references.

Event Handlers for the Results List

Event Handlers for the Results Page Two event handlers are required for the processing procedure of the results page (results.htm), OnInitialization and OnInputProcessing.

OnInitialization

data: isbn_tab TYPE isbn_tab. CALL METHOD cl_book_shop=>search_book EXPORTING author = author title = title publisher = publisher ISBN = ISBN keyword = keyword IMPORTING isbn_tab = isbn_tab EXCEPTIONS no_search_parameter = 2 invalid_isbn = 4. if sy-subrc = 4. navigation->goto_page( 'invalid_isbn.htm' ). elseif sy-subrc <> 0. navigation->goto_page( 'error.htm' ). endif. IF sy-subrc = 0. CALL METHOD cl_book_shop=>get_book_data EXPORTING isbn_tab = isbn_tab IMPORTING bookcat_tab = bookcat_tab EXCEPTIONS empty_input_table = 2 invalid_isbn = 4. ENDIF. The data statement sets the data transfer for the ISBN table. The method search_book of the class cl_book_shop is used to search for book titles that match the user input. When this happens, the method search_book gets the page parameters author, title, publisher, isbn and keyword, and the parameter isbn_tab is returned with the results of the search. The following exceptions or errors are defined in search_book: •

There are no search parameters, that is, the user input fields are empty (sysubrc=2). This scenario is already taken care of by OnInputProcessing on the search page. Therefore, it cannot occur here.

•

The specified ISBN does not correspond to the conventions (sy-subrc=4). In this case, the ISBN error page (invalid_isbn.htm) is called.

•

An internal error occurs (sy-subrc<>0).

In this case, the general error page (error.htm) is called. If no errors occur, the method get_book_data of the class cl_book_shop is called, which finds suitable results. Sometimes, no suitable results are found, that is, isbn_tab is empty.

In this case, get_book_data returns sy-subrc = 2, and the table bookcat_tab is empty. The layout part checks for this scenario.

OnInputProcessing navigation->set_parameter( 's_cata_id' ). Based on the user input, the book page is opened for the book with the s_cata_id that was specified in the layout with the statement below: ">

Layout for the Book Page

Navigation Structure In our example, the navigation structure is important mainly for the search function. When the user enters search criteria on the search page (search.htm), a corresponding results list (results.htm) is output. The navigation request TORESULTS controls the navigation procedure that opens the results page. When the user orders a book on the page showing detailed information on individual books (showbook.htm), the page containing a confirmation of the order (corder.htm) is displayed. The navigation request TOORDER controls this navigation procedure. The navigation structure for your BSP application, which you set using the tab page Navigation, looks like this:

You have now created your own online bookshop as a BSP application. Once you have activated all the BSPs and the BSP application itself, call your application in the Web browser.

To Be Continued... In the next tutorial you will extend your online bookshop by adding an online shopping basket with cookies, and a function for creating new users.

Our Little Online Bookshop Using MVC and HTMLB Purpose In this tutorial we create the same online bookshop as in Tutorial 3 ( Our First Online Bookshop) but this time using MVC and HTMLB.

Introductory Comments This has the advantage over the previous BSP application that you have several components on one page, where each component is represented by a controller and a view. You should do this tutorial if you are used to creating BSP applications (ideally once you have completed all of the tutorials) and you want to use MVC and HTMLB to create your applications. You should also have already completed the short Model View Controller Tutorial.

Integration Each tutorial builds on the information presented in the previous one. You can also read the reference documentation on the SAP Web AS Architecture, which explains the system’s architecture and components: You can find documentation about the MVC Design Pattern in Model View Controller (MVC). You can find documentation on BSP extension HTMLB in the system: you can display detailed documentation for each HTMLB element in the Tag browser of the Web Application Builder.

Features In this tutorial you will learn how to: •

Recognize HTMLB elements TableView, Button, Tray, Group and so on.

•

How to create a page (view) that calls several sub-controllers

•

How you implement event handling with MVC

•

How you can control the rendering of individual cells in a table

Section Bookshop Structure describes how you set up the BSP application to be created. See Creating BSP Applications, Controllers and Views for the exact procedure.

Constraints This model does not explain the use of models; for this comparatively simple application you need controllers and views only. The tutorial ends without any defined error pages. You can find information about using and creating error pages in the MVC documentation in Creating Error Pages.

Bookshop Structure

Unlike the online bookshop without MVC, this bookshop is structured so that book searches, results lists and the detailed displays are summarized on one page. You can use this to clearly show how the MVC programming model "thinks". If you call the URL hidden behind the main controller in the browser, the following page is displayed:

Tha main controller bookshop.do calls view default.htm. This contains a page fragment, which represents the bookshop header (like Tutorial 3 but with HTMLB), as well as 3 HTMLB trays, which call the corresponding controllers.

The following graphic highlights the structure.

The URL is recognized by the SAP Web AS as a BSP application and is processed by the BSP runtime. This calls main controller bookshop.do up first, that is, method DO_REQUEST for the corresponding controller class is executed. This then calls the main view default.htm, which in turn uses element within HTMLB trays to call subcontrollers search.do, result.do and detail.do. These sub-controllers have views that they call.

You can now get going with the implementation! Creating BSP Applications, Controllers and Views

Creating BSP Applications, Controllers and Views In the Web Application Builder, create the following: •

A BSP application We have chosen tutorial_3 as the name. This is a sample BSP application contained in package SBOOKSHOP. Pay attention to the customer namespaces when you are naming your BSP application.

Select your BSP application (Properties tabstrip) as Stateful. This is recommended when you work with sub-controllers (see Bookshop Structure), because the main controller must recognize all sub-controllers when it delegates the data. It must also be instantiated. If you want to program the application as stateless, you must create sub-controllers in the DO_INIT method of that controller. You can find additional information about this in Stateful and Stateless. •

Next controller bookshop.do. This is the main controller that is also called using the URL by the browser. Method ON_REQUEST of the controller class of this controller is executed first of all. This calls the view default.htm. Creating Main Controller bookshop.do describes how you create this controller. search.do. This is the controller that is responsible for the book search. It must react to the searchbutton, process the book data that are entered, search for suitable books and then write these to an internal table. It then passes this table to view search.htm. Creating Controller search.do for the Search describes how you create this controller. result.do. This controller is responsible for outputting the books that are found as well as for event handling when a user clicks on a book to display detailed data about that book. Individual rendering of the author column must also be determined. Creating Controller result.do for the Results Page describes how you create this controller. detail.do. This controller is responsible for determining the detailed data for a selected book. It then passes this table to view detail.htm. Creating Controller search.do for the Detail Display describes how you create this controller.

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Following views default.htm. This is the main view that consists of the header and 3 HTMLB trays, which contain the search-, result- and detail controllers and the corresponding views. Creating Main View default.htm describes how you create this view. search.htm. Creating View search.htm for the Search describes how you create the view for inputting the search data. result.htm. Creating View result.htm for the Results List describes the view for displaying the results list with an HTMLB table view. detail.htm. This view returns details on a book selected in the results table. Creating View detail.htm for the Details Display describes how you create the view. about.htm. If no books were found in the search or the results table is empty for another reason, information about the bookshop should be displayed instead of the book details. Create the view as described in Creating View about.htm for the Detail Display.

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Page fragment head.htm, which is included in main view default.htm. Creating Page Fragment head.htm describes how you create this with HTMLB. A page with flow logic corder.htm. You can navigate to this from the detail.do controller. Like Our First Online Bookshop, you navigate to this page if you want to order a book. Creating Page with Flow Logic corder.htm describes how you create the page.

Further Developing the Online Bookshop Purpose Welcome to the fourth tutorial! In this tutorial, you will further develop the functions of the Online Bookshop.

Introductory Comments Some important functions, such as customer administration and a shopping basket, are still missing from your online bookshop. This tutorial shows you how to add these functions to the application. The application is a stateless one (see Stateful and Stateless Applications), which means that any books selected by the user remain in the shopping basket, even if the connection is interrupted. For example, if the customer is in the middle of ordering a book, goes to visit another site, and then comes back to the bookshop, all the details of the order are still there, thanks to a cookie on the client side which retains the relevant information. The new bookshop functionality is described under What’s New?.

Integration Each tutorial builds on the information presented in the previous one. This tutorial requires the Online Bookshop (or Our Little Online Bookshop Using MVC and HTMLB) from Tutorial 3. You can also read the reference documentation on the SAP Web AS Architecture, which explains the system’s architecture and components:

Features In this tutorial you will learn how to: •

Use an application class (CL_BSP_TUTORIAL)

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Check user input and write it to the database

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Set cookies on the client side to store information in a stateless application

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Use caching functions

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Use the messages object

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Use the Online Text Repository (OTR)

Let’s get started!

What’s New? In this tutorial, the online bookshop that you created in the last tutorial (Online Bookshop) will be extended to include the following functions and BSPs: •

The page newuser.htm is used to register new customers. New customer data is stored in the customer table BSCUSTOMER. The page cnewuser.htm shows the

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customer that the registration has been successfully completed. For subsequent orders, the customer simply logs on on the page order.htm using his or her user ID (e-mail address) and password. The page basket.htm is the most important addition. This page displays the current status of the shopping basket. The user can delete entries and modify the quantity of an item. If the connection is terminated and then re-opened, the current status of the shopping basket can be regenerated using a cookie. Initally, you will use the application class CL_BSP_TUTORIAL to implement the above functionality. This class contains the methods for maintaining the shopping basket. Caching is used with the results page results.htm. Error messages that are output in the case of incorrect user information are implemented using the messages object. Error pages error.htm and invalid_isbn.htm, which are available in the third tutorial, are not used as a result. Some of the error messages have been declared as online text repository texts as an example. OTR texts have the advantage that they are connected to the SAP translation system.

The ways in which the online bookshop can be extended are described in the section Extending the Online Bookshop.

Extending the Online Bookshop In this section, you will extend the first page of the Online Bookshop by adding one line to the header page fragment. This line enables the user to go to the standard pages (Search, Create New User, Shopping Basket, and About) from any page.

Users use these pages to do the following: • • • •

Go to the search page Create a new user, that is, register themselves Display the current shopping basket Display the information page (about.htm)

The search function and the detailed book data display are transferred from the Online Bookshop. The user registration function is also new:

On this page, the customer (user) enters his or her name, address, company, and password. When the user clicks the done button, the data is checked for completeness and for identical passwords, and is then entered in the database table BSCUSTOMER. If the registration is successful, the following page appears:

The next time this user wants to place an order, he or she only needs to enter his or her email address and password. Adding an administration function for the shopping basket is another way of further extending the functionality of the Online Bookshop. When the shopping basket is empty, the page basket.htm looks like this:

If you search for a book, select it, and place it in the shopping basket, the shopping basket then looks like this:

On this page, the user can change the number of books, remove items from the basket, and update the basket. Once the user has completed the order, he or she chooses Order Basket to place the order. The following page appears:

On this page, the user enters his or her e-mail and password to authenticate the login. If the user is not yet a registered customer, he or she can also register on this page. If the e-mail address and password entered are correct, this activates the order. The page corder.htm opens.

This completes this addition to the bookshop. In the next step, you will learn how to trigger the ordering process, for example, by means of a BAPI. The BAPI in turn triggers the creation of an invoice, the deletion of a book from the bookshop, and the delivery of an item. The method for processing this BSP application is described in section Processing Procedure. For information on the data model in the SAP System, see the section Data Structures.

Go to Processing Procedure, to Data Structures, or to Creating BSP Applications and Pages.

Creating BSP Applications and Pages Prerequisites You have implemented the Online Bookshop as a BSP application.

Procedure

Make a copy of the existing BSP application to a new one, with a freely definable name in the customer namespace. In our example, we used tutorial_4. To do this, go to the Web Application Builder and open the BSP application tutorial_3. Right-click on the BSP application and choose Copy. In the popup that appears, enter ‘tutorial_4’ in the field Target Application.

In the field Target Application, enter the name of your new BSP application. Now create from scratch the following BSPs: Page Name

Meaning

basket.htm

Shopping Basket Page This page implements the shopping basket function. The user is taken to this page when he or she places a book in the basket, or modifies the contents of the basket.

order.htm

Order Page The user is taken to this page when he or she wants to order the current contents of the shopping basket. At this stage, the user has to authenticate himself or herself, otherwise the ordering process cannot continue.

newuser.htm

Registration Page This page is used to register new customers. The customers enter their email address to identify themselves.

cnewuser.htm

Registration Confirmation Page This page confirms that a new customer has registered successfully. The customer’s data is stored in the database table BSCUSTOMER of the package in question (see Data Model for the Bookshop Tutorials).

Some existing pages and page fragments must be changed. These modifications are described in the following sections:

Modifying the Title Bar head.htm Modifying the Order Confirmation Page corder.htm Modifying the Entry Page default.htm Modifying the Results Page results.htm Modifying the Search Page search.htm