44233767 WEB DYNPRO Dynamic Runtime Modifications

8/6/2019 44233767 WEB DYNPRO Dynamic Runtime Modifications

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SAP AG 2005, Title of Presentation / Speaker Name / #

Introduction

Modifying the context structure at runtime

Modifying the UI Element hierarchy at runtime The use of dynamic actions

Contents:

Dynamic Modifications at Runtime


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Dynamic Modifications at Runtime: Unit Objectives

After completing this unit, you will be able to:

Understand what is dynamic programming

Dynamically modify and create UI elements

Dynamically create context elements

Dynamically bind UI element values to context

elements

Dynamically create actions


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Dynamic Runtime Modifications

What is type of dynamic modifications can be made at

runtime?

Dynamic Context ManipulationThe creation, modification and deletion of context nodes andattributes

Dynamic UI ManipulationThe creation, modification and deletion of UI elements

DynamicAssignment ofActions to UI Elements


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Dynamic Runtime Modifications

There are several situations in which type of coding could berequired:

When the structure of your data is not known until runtime

When you want the behaviour of a screen to be generic andtherefore dynamic

When you are writing utility components that must function ina generic manner

Etc

Under what circumstances should I write coding that

performs dynamic modifications?


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Dynamic Context Data Creation

Example of context

metadata to be created

dynamically?Context Root (c=1..1, s=true)FLIGHTS (c=0..n, s=true)

Context Metadata to be

created at runtime

BOOKINGS (c=0..n, s=false)

PRICE

CARRID

CONNID

FLDATE

BOOKID

CUSTOMID

CLASS

PASSNAME


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Coding steps:

Obtain a reference to the metadata of

the context node that will act as the new

nodes parent. In this case, we are

creating an independent node, therefore

we get a reference to the metadata of

the root node.

Call static method

create_nodeinfo_from_struct( ) from

helper class cl_wd_dynamic_tool

A DDIC Structure can be used for the

attribute creation.

Dynamic Node Creation (1)

Context Root (c=1..1, s=true)

FLIGHTS (c=0..n, s=true)

Context Metadata to be

created at runtime

BOOKINGS (c=0..n, s=false)

PRICE

CARRID

CONNID

FLDATE

BOOKID

CUSTOMID

CLASS

PASSNAME

DDIC Structure SFLIGHT


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Dynamic Node Creation related to a structure

Coding steps:

Obtain a reference to the metadata of the context node that will act as the

new nodes parent.

Call static method create_nodeinfo_from_struct( ) from helper class

cl_wd_dynamic_tool to create from a DDIC structure a node.

DATA: rootnode_info TYPE REF TO if_wd_context_node_info,table_name type string value 'SFLIGHT',node_name type string value 'CONNECTIONS'.

* get root node info of contextrootnode_info = wd_context->get_node_info( ).

* create node named CONNECTIONS of sflightcl_wd_dynamic_tool=>create_nodeinfo_from_struct(parent_info = rootnode_infonode_name = node_namestructure_name = table_name

is_multiple = abap_falseis_mandatory = abap_true ).

Cardinality 11


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Dynamic Sub Node Creation related to a structure

DATA: dyn_node type ref to if_wd_context_node,dyn_node_info TYPE REF TO if_wd_context_node_info,node_name TYPE string value 'FLIGHTS',. . .

* navigate from to via lead selectiondyn_node = wd_Context->get_Child_Node( Name = node_name ).dyn_node_info = dyn_node->get_node_info( ).

* create sub node named BOOKINGS of sbookcl_wd_dynamic_tool=>create_nodeinfo_from_struct(parent_info = dyn_node_infonode_name = 'BOOKINGS'structure_name = 'SBOOK'is_multiple = abap_trueis_mandatory = abap_false ).


FLIGHTS (c=0..n, s=true)

BOOKINGS (c=0..n,s=false)

PRICE

CARRID

CONNID

FLDATE

BOOKID

CUSTOMID

CLASS

PASSNAME

Structure SBOOK

Coding steps:

Obtain a reference to node and reference to the

metadata of the context node that will act as the new

nodes parent

Call static method create_nodeinfo_from_struct( ) to

create from a DDIC structure a node


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Add a Dynamic Attribute to a Node


UI_ATTRIBUTES

BUTTON_VISIBILITY

TEXT_VISIBILITY

* add context attribute to nodedata: Ui_Attributes_info type ref to If_Wd_Context_Node_info.data: ls_att type WDR_CONTEXT_ATTRIBUTE_INFO.

* get node info of contextUi_Attributes_info = Node_Ui_Attributes->get_node_info( ).

ls_att-name = `TEXT_VISIBILITY`.ls_att-TYPE_NAME = 'WDUI_VISIBILITY'.

Ui_Attributes_info->add_attribute( ATTRIBUTE_INFO = ls_att ).

Coding steps:

Obtain a reference to the metadata of the parent node

that will contain the attribute

Fill structure ( WDR_CONTEXT_ATTRIBUTE_INFO )

with attribute properties

Add attribute to parent node


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Standard Hook Method View controller

Only a view controller has these hook methods.

The method WDDOMODIFYVIEWwill only be called if:

The view is part of the current view assembly and this is the

first time the view is required, or

The view is part of the current view assembly and an action

belonging to the same view controller has been processed.


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Principles of UI element manipulation

The following coding principles must be adhered to during UI element

manipulation:1. Only perform direct manipulation of UI element objects when it is not

possible to control their behaviour through context binding.

2. UI manipulation is only permitted within the wdDoModifyView()

method of a view controller.

3. wdDoModifyView() has a boolean parameter called firstTime.Typically, you will only build a dynamic UI element hierarchy whenfirstTime == true. This avoids rebuilding the UI element hierarchy

unnecessarily.

4. Do NOT implement any coding in wdDoModifyView() that modifies

the context! The context should be considered read-only during the

execution of this method.


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Dynamic UI manipulation (1)

Context Root

Connections

PRICE

CARRID

CONNID

FLDATE

Context Metadata UI Element Hierarchy tobe created at runtime

RootUIElementContainer

CARRIDLabel

CARRIDInput

CONNIDLabel

CONNIDInput

FLDATELabel

FLDATEInput

PRICELabel

PRICEInput


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Coding steps:

Check that this is the

first time the view has

been rendered

Obtain a reference to

the root UI elementcontainer

UI Element Hierarchy tobe created at runtime


Context Root

Connections

PRICE

CARRID

CONNID

FLDATE

Context Metadata

method WDDOMODIFYVIEW .

data: wd_container type ref to cl_wd_uielement_container,

. . .

* Check if first timecheck first_time = abap_true.

wd_container ?= view->get_element( 'ROOTUIELEMENTCONTAINER' ).


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Coding steps:

Create a new InputField UI

element object (bind to

context attribute

Create a new Label UI

element object

Set the Labels properties

as required

Add the Label object to the

UI element container

Set the InputFields

properties as required

Add the InputField to the

UI element container

InputField



InputField

Label

Label

bind

add

Context Root

Connections

PRICE

CARRID

CONNID

FLDATE

Context Metadata


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* Create label and input field** create a input fieldwd_input_field = cl_wd_input_field=>new_input_field( view = view

bind_value = 'CONNECTIONS.CARRID').

** create a label for the input fieldwd_label = cl_wd_label=>new_label( label_for = wd_input_field->id ).

** set matrix_head_data for the labelcl_wd_matrix_head_data=>new_matrix_head_data( element = wd_label ).

** add label to container

wd_container->add_child( wd_label ).

** set matrix_data for the input_fieldcl_wd_matrix_data=>new_matrix_data( element = wd_input_field ).

** add input field to containerwd_container->add_child( wd_input_field ).



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Dynamic Actions

Certain UI elements can trigger client-side events (e.g. pressing enter

in an InputField, toggling a CheckBox or selecting the row of atable).

In order for the client-side event to trigger the execution of a server-

side method, Web Dynpro uses the concept ofActions.

Actions can either be assigned declaratively to UI element events atdesign time, or dynamically at runtime.

Actions assigned dynamically can only refer to existing server-side

action handler methods. It is not possible to define the coding of an

action event handler dynamically; only to define which existing action

handler will be called when a client-side event is trapped.


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Action Declaration

Declared action

Coding requiredfor dynamic

assigned action


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* Create button

** create button UI elementwd_button = cl_wd_button=>new_button( text = 'Show Flights'on_action = 'SELECT_FLIGHTS' ).

** set matrix_head_data for the labelcl_wd_matrix_head_data=>new_matrix_head_data( element = wd_button ).

** add button to containerwd_container->add_child( wd_button ).

Create a Dynamic Button

Coding steps: Create a new Button UI

element object (assign an

predefined action)

Set the Button properties

as required

Add the Button to the UI

element containerButton



InputField

Label

Context Root

Connections

PRICE

CARRID

CONNID

FLDATE

Context Metadata

Button


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Was this a good approach?

Development Principle

Only if the required functionality of your application does notpermit design time declarations, then use a dynamicmodification approach.

All context node/attribute and UI elements which can be

created during design time should be created during designtime.


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Example for Dynamic Programming

Display the content ofANY table

Dynamic Context

Dynamic table UI element

Dynamic data retrieval


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Example for Dynamic Programming I

DATA:group_1 TYPE REF TO cl_wd_uielement_container,

new_tab TYPE REF TO cl_wd_table,dyn_node TYPE REF TO if_wd_context_node,tabname_node TYPE REF TO if_wd_context_node,rootnode_info TYPE REF TO if_wd_context_node_info,stru_tab TYPE REF TO data,tablename TYPE string.

FIELD-SYMBOLS TYPE table.

* get node info of context root noderootnode_info = wd_context->get_node_info( ).

* Get the name of the table to be createdtabname_node = wd_context->get_child_node( name = 'TABLE_DATA' ).tabname_node->get_attribute( EXPORTING name = 'NAME' IMPORTING value =tablename ).

translate tablename to upper case.

* create sub node of structure (tablename)cl_wd_dynamic_tool=>create_nodeinfo_from_struct(parent_info = rootnode_infonode_name = tablenamestructure_name = tablenameis_multiple = abap_true ).


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Example for Dynamic Programming II

* remove "old" table UI element from view , if necessarygroup_1 ?= view->get_element( 'GROUP_1' ).

group_1->remove_child( id = 'TESTTAB' ).

* * get instance of new nodedyn_node = wd_context->get_child_node( name = tablename ).

DATA new_tab TYPE REF TO cl_wd_table.

* create new UI element tablenew_tab = cl_wd_dynamic_tool=>create_table_from_node(ui_parent = group_1table_id = 'TESTTAB'node = dyn_node ).

** fill context node with data* create internal table of (tabletype)

CREATE DATA stru_tab TYPE TABLE OF (tablename).ASSIGN stru_tab->* TO .

* Get table contentSELECT * FROM (tablename) INTO CORRESPONDING FIELDS OF TABLE .

* Bind internal table to context nodedyn_node->bind_table( ).


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You should now be able to:

Understand what is dynamic programming

Dynamically modify and create UI elements

Dynamically create context elements

Dynamically bind UI element values to context

elements

Dynamically create actions

Web Dynpro Dynamic Programming: Unit Summary

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44233767 WEB DYNPRO Dynamic Runtime Modifications