How to use the action OnExpandAll on UI element Tree

Question

Hi, experts .
I am in WDA developing project and developing the screen which has Tree .
I want to expand all nodes when users click the button on the head of Tree .
I copied the application `WDT_TREE` and created Tree of my application successfully .
And I created the action OnExpandAll on my Tree and tried to create the function to expand all nodes .
But I do not know how to use the action OnExpandAll .
I can see the button to start action OnExpandAll on the head of Tree .
I am trying to write logic in the action . But it does not work successfully .
(In my tree , when I click the button for OnExpandAll , all nodes are outputted on root node .
Because my logic is wrong ... )
Please give me any hints .
Masao

Answer 1

Hi
As your case it is a recursive node.
then you have to create method and call it recursively for the expanall functionality.
do it like this.
create an attribute the node FOLDER
name = 'ISEXPANDED'
type = WDY_BOOLEAN.
Now bind the property expanded of treenode FOLDER UI to this attribute.
now go to the methods tab and create one method say name ZEXPANDALL.
in thsi method make one importing parameter of type ( type ref to ) if_wd_context_node. and name NODE.
then write the following code in this method.
method ZEXPANDALL .
DATA ELT TYPE WDR_CONTEXT_ELEMENT_SET.
DATA EL TYPE REF TO IF_WD_CONTEXT_ELEMENT.
data nd type ref to if_wd_context_node.
data nds type WDR_CONTEXT_CHILD_MAP.
data chld type wdr_context_child.
data nf type ref to if_wd_context_node_info.
data name type string.
ELT = node->GET_ELEMENTS( ).
LOOP AT ELT INTO EL.
  EL->SET_ATTRIBUTE(
  NAME = 'ISEXPANDED'
  VALUE = ABAP_TRUE
  data parent_key type string.
EL->get_attribute( exporting name = 'TEXT' importing value
= parent_key ).
* create the child nodes
    create_node(
      exporting
        cur_element = EL
        parent_key  = parent_key ).
nds = el->get_child_nodes( ).
loop at nds into chld.
  nd ?= chld-node.
  nf = nd->get_node_info( ).
name  = nf->get_name( ).
if name eq 'FOLDER'.
  zexpandall(                             "recursive call
  nd
endif.
  endloop.
  ENDLOOP.
endmethod.
NOw go to your eventhandler created for action expandall.
there write the following code.
method ONACTIONEXPANDALL .
DATA lo_nd TYPE REF TO if_wd_context_node.
  lo_nd = wd_context->get_child_node( 'FOLDER' ).
  ZEXPANDALL( lo_nd ).
endmethod.
thats it.
Thanks
sarbjeet singh