Dynamic Tree in ABAP WebDynpro

I program some trees in java webdynpro, but in abap wd it’s slightly different…easier on one side, but with no documentation could be quite complex.

Suppose you wish to build a dynamic tree, so you declare a tree control with a recursive node under it:

”

The tree node type shoud be binded to a context node which contain a recursive node under it; in this case the treeservices is the upper node of the tree in the context.

the event ‘onLoadChildren’ is raised when you expand a tree node; here the critical role is assumed by the parameter PATH which tell us positioning.

Here, the method ZGETLEAF of the component controller will retrieve the data for the expanded node:

method ZGETLEAF . DATA ls_treeservices TYPE wd_this->Element_treeservices. data: treeserv type table of wd_this->element_treeservices. data valore type char10. data tabhier type table of zzservhier. data shier type zzservhier. data nodo type ref to if_wd_context_node. data myset type WDR_CONTEXT_ELEMENT_SET. data valflag. data cxcontext type ref to cx_wd_context. data prestazione type char10. data prestaziones type string. data resto type string. data espanso type flag. data nodes type WDR_CONTEXT_CHILD_MAP. data snodes type WDR_CONTEXT_CHILD. data nodeinfo type ref to IF_WD_CONTEXT_NODE_INFO. data nodename type string. data indice type i. data loaded type flag. indice = parent->get_index( ). nodo = node->get_child_node( index = indice name = ‘TREELEAF’ ). call method parent->get_attribute exporting name = ‘EXPANDED’ importing value = espanso. check espanso = ‘X’. call method parent->get_attribute exporting name = ‘LOADED’ importing value = loaded. check loaded = space. call method parent->get_attribute exporting name = ‘CODICE’ importing value = prestaziones. split prestaziones at ‘-‘ into prestazione resto. call method parent->set_attribute exporting name = ‘LOADED’ value = ‘X’. CALL FUNCTION ‘ZZ_GET_CORDER_HIERARCHY’ EXPORTING I_TALST = prestazione LEVEL = ’01’ TABLES HIERARCHY = tabhier . loop at tabhier into shier. * concatenate shier-prestazione ‘-‘ * shier-descrizione into prestaziones. prestaziones = shier-prestazione. ls_treeservices-codice = prestaziones. ls_treeservices-nome = shier-descrizione. ls_treeservices-figli = shier-cartella. append ls_treeservices to treeserv. endloop. nodo->bind_table( new_items = treeserv set_initial_elements = abap_false ). endmethod.

Of course, I use an attribute in the tree context to know if I already loaded the data for that branch.

Also the first level of the tree is loaded in the WDDOINIT method of the view(via calling of a component controller method).

2 Comments

You must be Logged on to comment or reply to a post.

Former Member November 12, 2007 at 4:36 am

DemoTree
WDT_TREE
DEMO_TABLE_WITH_TREE

Thanks
Venkata Ramakrishna Ramisetti

like (0)
1. Former Member Post authorNovember 12, 2007 at 4:58 am
  
  Hi Venkata,
  
  of course you’re right…I wasn’t aware of WDT_TREE sample for dynamic tree…I would had save a lot of time…
  Thanks a lot
  Paolo
  
  like (0)