Invoking View Trees From Application Pages

This section outlines the development steps and provides some sample code to view trees from an application page. It provides two methods of how to view trees from application pages:

Without multi-node selection.
With multi-node selection.

To view a tree from an application page:

Add the PSTREEVIEWERWRK page to your component as a hidden page.
Add a field to a work record that will then be used as a Command Button or Hyperlink to your secondary page.

The user selects this button or link to invoke the Tree Viewer page. You also need to add the following sample code to the FieldChange event for this field.
Add the Command Button or Hyperlink to the application page.
Add a Secondary Page control to the application page, and set the secondary page to PSTREEVIEWER.

The Secondary Page control must be placed on the page at a level higher than level 3.

In addition, the Command button or Hyperlink to invoke the PSTREEVIEWER secondary page must be placed on the same level as a secondary page control.
Add the application PeopleCode, which should do the following:
1. Set the values of the Tree’s key fields on the PSTREEVIEWWRK record.
2. Determine whether a node has been previously selected, and if so, setting the Tree_Node field to be the ID of the selected node:
  
  If a leaf has been previously selected, your code should do the following:
  
  — Populate the Range_From and Range_To fields with the selected leaf values
  
  — Set the Tree_Node field to the parent node
  
  — Set the Leaf_Selected field to "Y"
3. Set any of the display options that you want to use.
4. Display the Tree Viewer secondary page (PSTREEVIEWER) by calling the DoModal PeopleCode function.
5. Optionally, check the return code value and storing the ID of the selected node if the user selected a node and clicked the OK or Select button.

/* Note: Keys of Tree are stored in &SetId,&TreeName variables. 
Assume that application has Leaf selected with values stored in variables &Range⇒
From; &RangeTo and has parent node name stored in &TreeNode variable. QE_TREETEST_⇒
WRK Record holds input and received output values. */

/*Tree to open specification */
PSTREEVIEWWRK.SETID = &SETID;
PSTREEVIEWWRK.SETCNTRLVALUE = " ";
PSTREEVIEWWRK.TREE_NAME = &TREENAME;
PSTREEVIEWWRK.TREE_BRANCH = " ";
PSTREEVIEWWRK.EFFDT = %DATE; /* Get Latest Tree as of Today */

/* Tree appearance specification */
PSTREEVIEWWRK.PAGE_SIZE = 60;
PSTREEVIEWWRK.SHOW_LEAVES = "Y";
PSTREEVIEWWRK.SHOW_LEVELS = "Y";
PSTREEVIEWWRK.MULTINODESELECTION = "N";

/* Leaf input specification */
/* (Assuming QE_TREETEST_WK.LEAF_SELECTED ="Y"; */
PSTREEVIEWWRK.LEAF_SELECTED = QE_TREETEST_WRK.LEAF_SELECTED;
PSTREEVIEWWRK.TREE_NODE = &TreeNode;
PSTREEVIEWWRK.RANGE_FROM = &RangeFrom;
PSTREEVIEWWRK.RANGE_TO = &RangeTo;

/* Opening the PSTREEVIEWER secondary page */
&rslt = DoModal(Page.PSTREEVIEWER, " ", - 1, - 1);

/* populating the application Record (QE_TREETEST_WRK) with output values from⇒
 user selection in Tree */
If &rslt = 1 Then
   QE_TREETEST_WRK.TREE_NODE = PSTREEVIEWWRK.TREE_NODE;
   QE_TREETEST_WRK.TREE_LEVEL_NUM = PSTREEVIEWWRK.TREE_LEVEL_NUM;
   QE_TREETEST_WRK.TREE_LEVEL = PSTREEVIEWWRK.TREE_LEVEL;
   QE_TREETEST_WRK.TREE_LEVEL_DESCR = PSTREEVIEWWRK.TREE_LEVEL_DESCR;
   QE_TREETEST_WRK.RANGE_FROM = PSTREEVIEWWRK.RANGE_FROM;
   QE_TREETEST_WRK.RANGE_TO = PSTREEVIEWWRK.RANGE_TO;
   QE_TREETEST_WRK.DYNAMIC_FLAG = PSTREEVIEWWRK.DYNAMIC_FLAG;
   QE_TREETEST_WRK.MESSAGE_SET_NBR = PSTREEVIEWWRK.MESSAGE_SET_NBR;
   QE_TREETEST_WRK.MESSAGE_NBR = PSTREEVIEWWRK.MESSAGE_NBR;
End-If;

The following is the sample PeopleCode (Method A), which would be part of the FieldChange event triggered from a Command Button or Hyperlink command on the application page:

In some cases, you may need to use the Component Level Record variable &cPSTREEVIEWWRK to set values for the tree. For example, if the application added the Tree Viewer secondary page to the application’s secondary page and cannot reach the record from the component buffer. The following is the sample PeopleCode illustrating the use of the variable:

Component Record &cPSTREEVIEWWRK;
Component boolean &gbShowTreeLeaves;
Local number &rslt;

/* opening the Tree Viewer secondary page */

&cPSTREEVIEWWRK = CreateRecord(Record.PSTREEVIEWWRK);

&cPSTREEVIEWWRK.SETID.Value = &SETID;
&cPSTREEVIEWWRK.SETCNTRLVALUE.Value = " ";
&cPSTREEVIEWWRK.TREE_NAME.Value = &TREENAME;
&cPSTREEVIEWWRK.TREE_BRANCH.Value = " ";
&cPSTREEVIEWWRK.EFFDT.Value = %DATE; /* Get Latest Tree as of Today */;
&cPSTREEVIEWWRK.PAGE_SIZE.Value = 60;
&cPSTREEVIEWWRK.SHOW_LEVELS.Value = "Y";
&cPSTREEVIEWWRK.MULTINODESELECTION.Value = "N";

If &gbShowTreeLeaves Then
   &cPSTREEVIEWWRK.SHOW_LEAVES.Value = "Y";
Else
   &cPSTREEVIEWWRK.SHOW_LEAVES.Value = "N";
End-If;

&rslt = DoModal(Page.PSTREEVIEWER, "", - 1, - 1);

/* reading output value in a case when Component Level Record variable &c⇒
PSTREEVIEWERWRK is used. */

If &rslt = 1 Then
   QE_TREETEST_WRK.TREE_NODE = &cPSTREEVIEWWRK.TREE_NODE.value;
   QE_TREETEST_WRK.TREE_LEVEL_NUM = &cPSTREEVIEWWRK.TREE_LEVEL_NUM.value;
   QE_TREETEST_WRK.TREE_LEVEL = &cPSTREEVIEWWRK.TREE_LEVEL.value;
   QE_TREETEST_WRK.TREE_LEVEL_DESCR = &cPSTREEVIEWWRK.TREE_LEVEL_DESCR.value;
   QE_TREETEST_WRK.RANGE_FROM = &cPSTREEVIEWWRK.RANGE_FROM.value;
   QE_TREETEST_WRK.RANGE_TO = &cPSTREEVIEWWRK.RANGE_TO.value;
   QE_TREETEST_WRK.DYNAMIC_FLAG = &cPSTREEVIEWWRK.DYNAMIC_FLAG.value;
   QE_TREETEST_WRK.MESSAGE_SET_NBR = &cPSTREEVIEWWRK.MESSAGE_SET_NBR.value;
   QE_TREETEST_WRK.MESSAGE_NBR = &cPSTREEVIEWWRK.MESSAGE_NBR.value;
   
   EndModal(1);
Else
   EndModal(0);
End-If;

Note:

The name of the variable &cPSTREEVIEWWRK is hard-coded and should not be changed.

The segment of code in italics reads the results that came from the tree. (Node or leaf selected).