regarding concrete class that implements interface if_wd_context_node

[Former Member]

Hello,

I am new to the webdynpro. i have seen code for accessing the context node using interface if _wd_context_node.

but i am totally confused by seeing the code .As we know that for accessing interface method , concrete class must implement interface . after that by using refrence variable of iterface if_wd_context_node  or concrete class variable we can access the method of interface.

but unfortunately i have not seen any class that implement implement  if _wd_context_node.  one class that implement this interface is abstract class ie

CL_WDC_CONTEXT_node. but all of we know that we can not create the object of abstract class.

So please tell me the concrete class name that implement interface if _wd_context_node. so that i can proceed by coding. urgently

[Former Member · Accepted solution]

Hi ashish,

    Yes you are right  for accessing interface method , concrete class must implement interface .

The same is happening in web dynpo also.

Here we use all these from WDA controller referrence & context referrence. I hope u are clear about the concept of controller.

For example whenever u create any view, by default three attribute will be created ( Chek attribute tab).

WD_THIS , WD_CONTEXT ,  WD_COMP_CONTROLLER.

We implement all this interfaces from this referrence actually.

Therefor to access any note code will generate like this :-

  DATA lo_nd_node_1 TYPE REF TO if_wd_context_node.
  DATA lt_node_1 TYPE wd_this->Elements_node_1.

* navigate from <CONTEXT> to <NODE_1> via lead selection
  lo_nd_node_1 = wd_context->get_child_node( name = wd_this->wdctx_node_1 ).

( Therefor you can see the node referrence created from wd_context.)

Double click on this & you will get the declaration the context & methods.

Regards,

Monishankar Chatterjee

[Former Member · Accepted solution]

Hi,

thanks for your response . but some misconception is  their. firstly wd_this refers to local controller interface but my concern is where is the actaual concrete class which implement the interface or class implicitly works in background.

[former_member182915]

hello ashish narayan

To access any component in other component in a application you  need that components usage i.e nothing but reference of that controller .by default  SAP provide the reference of component controller to all controller as  wd_comcontroller.  if want to verify go to attribute tab in view controller & window controller.

scenario-1

for example in component controller (i.e cc) define  a context node with mara node and matnr, ersda, ernam,pstat, mtart  attribute  and create a custom method Fill in method tab

method FILL .

  DATA LO_ND_MARA TYPE REF TO IF_WD_CONTEXT_NODE.

  DATA LT_MARA TYPE WD_THIS->ELEMENTS_MARA.

* navigate from <CONTEXT> to <MARA> via lead selection

  LO_ND_MARA = WD_CONTEXT->GET_CHILD_NODE( NAME = WD_THIS->WDCTX_MARA ).

* @TODO handle non existant child

* IF lo_nd_mara IS INITIAL.

* ENDIF.

** @TODO compute values

** e.g. call a model function

select matnr ersda ernam pstat mtart from mara into table it_mara up to 5 rows.

  LO_ND_MARA->BIND_TABLE( NEW_ITEMS = LT_MARA SET_INITIAL_ELEMENTS = ABAP_TRUE ).

endmethod.

after  mapping of context node  between view & component controller by drag & drop

create a table in main view by taking mara node of view controller .

and in the wddoinit () method of view controller call the component controller custom method fill with component controller reference.

as bellow

DATA LO_COMPONENTCONTROLLER TYPE REF TO IG_COMPONENTCONTROLLER .

  LO_COMPONENTCONTROLLER =   WD_THIS->GET_COMPONENTCONTROLLER_CTR( ).

    LO_COMPONENTCONTROLLER->FILL(

    ).

the above code is system generated.

or simply

  wd_comcontroller->FILL( ).

so after executing the application you get Ur table is filled. i.e is only possible of taking reference of component controller.

hope this note help you.