Setting up structured nodes
A structured node is a node where each new level is created recursively from the same SDO. This means that you can expand a node any number of times, and you do not have to set up individual nodes for each level in the tree.
This section explains the process of setting up a node for a structured table using the gsm_node table, illustrated in Figure 9–5, from the Repository database (ICFDB) as an example.
As you can see from this diagram, the gsm_node table is linked to itself and is using the parent_node_obj and node_obj fields.
You can define a single node record to identify a node to expand indefinitely depending on its data. To do this, you create a node record that indicates that the SDO can expand into child nodes. To illustrate, create a node in the Tree Node Control window using the values shown in Figure 9–6. Note the information in the Structure tab as shown:
The Structured node check box is enabled and identifies this node as a structured table node and allows related child nodes to be created.
When specifying values for a structured node, you must specify the following values in the following order:·
For example, if you want to list only those nodes that do not have a parent (that is, nodes that are the highest nodes in the structure), the root node would filter only on records where the parent_node_obj = 0. Since a node only has a value in the parent_node_obj field if it is a child of another node, you can specify the parent_node_obj as the parent key field. A child node is linked to its parent by checking that the parent’s key field value (node_obj) is equal to the parent_node_obj field for any other nodes. This makes the node_obj field the table’s child key field. Where both of these key fields have a data type of DECIMAL, the fourth value would be DECIMAL. Thus, the Fields To Store value would be:
Once you have set up all the other standard information, you can create a dynamic TreeView in the normal way by creating a record in the Dynamic TreeView Builder.