dynamic runtime modifs webdynpro
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SAP AG 2005, Title of Presentation / Speaker Name / 1
Introduction
Modifying the context structure at runtime
Modifying the UI Element hierarchy at runtime
The use of dynamic actions
Contents:
Dynamic Modifications at Runtime
SAP AG 2005, Title of Presentation / Speaker Name / 2
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
SAP AG 2005, Title of Presentation / Speaker Name / 3
Dynamic Runtime Modifications
What is type of dynamic modifications can be made at runtime?
Dynamic Context ManipulationThe creation, modification and deletion of context nodes and attributes
Dynamic UI ManipulationThe creation, modification and deletion of UI elements
Dynamic Assignment of Actions to UI Elements
SAP AG 2005, Title of Presentation / Speaker Name / 4
Dynamic Runtime Modifications
There are several situations in which type of coding could be required:
When the structure of your data is not known until runtime When you want the behaviour of a screen to be generic – and
therefore dynamic When you are writing utility components that must function in
a generic manner Etc…
Under what circumstances should I write coding that performs dynamic modifications?
SAP AG 2005, Title of Presentation / Speaker Name / 5
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
SAP AG 2005, Title of Presentation / Speaker Name / 6
Coding steps:
Obtain a reference to the metadata of the context node that will act as the new node’s 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
SAP AG 2005, Title of Presentation / Speaker Name / 7
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 node’s 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 context rootnode_info = wd_context->get_node_info( ).
* create node named CONNECTIONS of sflight cl_wd_dynamic_tool=>create_nodeinfo_from_struct( parent_info = rootnode_info node_name = node_name structure_name = table_name is_multiple = abap_false is_mandatory = abap_true ).
Cardinality 1…1
SAP AG 2005, Title of Presentation / Speaker Name / 8
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 <CONTEXT> to <FLIGHTS> via lead selection dyn_node = wd_Context->get_Child_Node( Name = node_name ). dyn_node_info = dyn_node->get_node_info( ).
* create sub node named BOOKINGS of sbook cl_wd_dynamic_tool=>create_nodeinfo_from_struct( parent_info = dyn_node_info node_name = 'BOOKINGS' structure_name = 'SBOOK' is_multiple = abap_true is_mandatory = abap_false ).
Context Root (c=1..1, s=true)
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 node’s parent
Call static method create_nodeinfo_from_struct( ) to create from a DDIC structure a node
SAP AG 2005, Title of Presentation / Speaker Name / 9
Add a Dynamic Attribute to a Node
Context Root (c=1..1, s=true)
UI_ATTRIBUTES
BUTTON_VISIBILITY
TEXT_VISIBILITY
* add context attribute to node data: Ui_Attributes_info type ref to If_Wd_Context_Node_info. data: ls_att type WDR_CONTEXT_ATTRIBUTE_INFO.
* get node info of context Ui_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
SAP AG 2005, Title of Presentation / Speaker Name / 10
Standard Hook Method – View controller
Only a view controller has these hook methods.
The method WDDOMODIFYVIEW will 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.
SAP AG 2005, Title of Presentation / Speaker Name / 11
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 when firstTime == 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.
SAP AG 2005, Title of Presentation / Speaker Name / 12
Dynamic UI manipulation (1)
Context Root
Connections
PRICE
CARRID
CONNID
FLDATE
Context Metadata UI Element Hierarchy to be created at runtime
RootUIElementContainer
CARRIDLabel
CARRIDInput
CONNIDLabel
CONNIDInput
FLDATELabel
FLDATEInput
PRICELabel
PRICEInput
SAP AG 2005, Title of Presentation / Speaker Name / 13
Dynamic UI manipulation (2)
Coding steps:
Check that this is the first time the view has been rendered
Obtain a reference to the root UI element container
UI Element Hierarchy to be created at runtime
RootUIElementContainer
Context Root
Connections
PRICE
CARRID
CONNID
FLDATE
Context Metadata
method WDDOMODIFYVIEW . data: wd_container type ref to cl_wd_uielement_container, . . .
* Check if first time check first_time = abap_true.
wd_container ?= view->get_element( 'ROOTUIELEMENTCONTAINER' ).
SAP AG 2005, Title of Presentation / Speaker Name / 14
Dynamic UI manipulation (3)
Coding steps:
Create a new InputField UI element object (bind to context attribute
Create a new Label UI element object
Set the Label’s properties as required
Add the Label object to the UI element container
Set the InputField’s properties as required
Add the InputField to the UI element container
InputField
UI Element Hierarchy to be created at runtime
RootUIElementContainer
InputField
Label
Label
bind
add
Context Root
Connections
PRICE
CARRID
CONNID
FLDATE
Context Metadata
SAP AG 2005, Title of Presentation / Speaker Name / 15
* Create label and input field** create a input field wd_input_field = cl_wd_input_field=>new_input_field( view = view bind_value = 'CONNECTIONS.CARRID').** create a label for the input field wd_label = cl_wd_label=>new_label( label_for = wd_input_field->id ).
** set matrix_head_data for the label cl_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_field cl_wd_matrix_data=>new_matrix_data( element = wd_input_field ).
** add input field to container wd_container->add_child( wd_input_field ).
Dynamic UI manipulation (4)
SAP AG 2005, Title of Presentation / Speaker Name / 16
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 a table).
In order for the client-side event to trigger the execution of a server-side method, Web Dynpro uses the concept of Actions.
Actions can either be assigned declaratively to UI element events at design 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.
SAP AG 2005, Title of Presentation / Speaker Name / 17
Action Declaration
Declared action
Coding required for dynamic
assigned action
SAP AG 2005, Title of Presentation / Speaker Name / 18
* Create button** create button UI element wd_button = cl_wd_button=>new_button( text = 'Show Flights' on_action = 'SELECT_FLIGHTS' ).** set matrix_head_data for the label cl_wd_matrix_head_data=>new_matrix_head_data( element = wd_button ).** add button to container wd_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 container
Button
UI Element Hierarchy to be created at runtime
RootUIElementContainer
InputField
Label
Context Root
Connections
PRICE
CARRID
CONNID
FLDATE
Context Metadata
Button
SAP AG 2005, Title of Presentation / Speaker Name / 19
Was this a good approach?
Development Principle
Only if the required functionality of your application does not permit design time declarations, then use a dynamic modification approach.
All context node/attribute and UI elements which can be created during design time should be created during design time.
SAP AG 2005, Title of Presentation / Speaker Name / 20
Example for Dynamic Programming
Display the content of ANY table
Dynamic Context
Dynamic table UI element
Dynamic data retrieval
SAP AG 2005, Title of Presentation / Speaker Name / 21
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 <tab> TYPE table.
* get node info of context root node rootnode_info = wd_context->get_node_info( ).
* Get the name of the table to be created tabname_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_info node_name = tablename structure_name = tablename is_multiple = abap_true ).
SAP AG 2005, Title of Presentation / Speaker Name / 22
Example for Dynamic Programming II
* remove "old" table UI element from view , if necessary group_1 ?= view->get_element( 'GROUP_1' ). group_1->remove_child( id = 'TESTTAB' ).
* * get instance of new node dyn_node = wd_context->get_child_node( name = tablename ).
DATA new_tab TYPE REF TO cl_wd_table.
* create new UI element table new_tab = cl_wd_dynamic_tool=>create_table_from_node( ui_parent = group_1 table_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 <tab>.
* Get table content SELECT * FROM (tablename) INTO CORRESPONDING FIELDS OF TABLE <tab>.
* Bind internal table to context node dyn_node->bind_table( <tab> ).
SAP AG 2005, Title of Presentation / Speaker Name / 23
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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