A tree consisting of content from a com.webmethods.caf.faces.data.tree.ITreeContentProvider object. An ITreeContentProvider creates a flattened view of the tree, iterating over the tree structure in depth-first order. You can choose to use a custom ITreeContentProvider. The Composite Application Framework library provides the following providers that you can use with tree data:

• com.webmethods.caf.faces.data.tree.object.NodeTreeContentProvider
• com.webmethods.caf.faces.data.tree.object.ListTreeContentProvider

NodeTreeContentProvider

The NodeTreeContentProvider works with tree data that is in the form of a tree object model such as data in an XML document loaded into a W3C DOM tree. You need to provide the NodeTreeContentProvider with a data model that implements the com.webmethods.caf.faces.data.tree.INode interface, and the NodeTreeContentProvider handles the rest.

The com.webmethods.caf.faces.data.tree.object.XMLDOMNode class is an INode that wraps a W3C DOM tree object model. You can instantiate the INode with the DOM node that serves as the root of the tree, and an XPath string that specifies a unique ID for each node. For example, with the following XML, use the uri attribute of each node for a unique ID:

<folder name='Root Folder' uri='/folders/'>
     <folder name='System' uri='/folders/system/'>
          ...
     </folder>
     <folder name='Public Folders' uri='/folders/public/'>
          ...
     </folder>
     <folder name='Users' uri='/folders/users/'>
          ...
     </folder>
</folder>


Use the XMLUtil.loadDocumentFromString() static utility method to load an XML document into a W3C DOM tree. Create an XMLDOMNode tree model using the document's root element as the tree model root, and using the uri attribute as each node's unique ID. With the INode tree model, you can instantiate a NodeTreeContentProvider. The tree control uses the ITreeContentProvider when you configure the control's value property.

org.w3c.dom.Document doc =
com.webmethods.caf.common.XMLUtil.loadDocumentFromString(xml);
INode root = new XMLDOMNode(doc.getDocumentElement(), "@uri");
ITreeContentProvider tree = new NodeTreeContentProvider(root);


ListTreeContentProvider

The ListTreeContentProvider works with tree data in the form of a list of rows, where each row has a property that identifies the parent of the row or the children of the row. Tree data stored in a relational database can take this parent/child form. You need to supply the ListTreeContentProvider with the list of rows, a ValueBinding expression that specifies a unique ID for each row, and a ValueBinding expression that specifies the parent ID for each row, or a ValueBinding expression that specifies a list of child IDs for each row.

In the following example, the row data is simply a list of String arrays. The first item in each String array is the row's parent ID, specified using a ValueBinding expression #{row[0]}). Rows where the parent ID is null are displayed as roots. The second item in each String array is the row's unique ID, specified using a ValueBinding expression #{row[1]}. The example below shows that in the first row, alice has two children, albert and agnes.

java.util.List list = java.util.Arrays.asList(new Object[] {
     new Object[] {null,"alice","apple","astros"},
     new Object[] {null,"bob","banana","brewers"},
     new Object[] {null,"carla","cantaloupe","cubs"},
     new Object[] {null,"dirk","dingleberries","dodgers"},
     new Object[] {null,"edna","eggplant","expos"},
     new Object[] {null,"frank","fruitcake","phillies"},
     new Object[] {"alice","albert","pineapple","texans"},
     new Object[] {"alice","agnes","cranapple","stars"},
     new Object[] {"bob","bertha","banan-o-rama","packers"},
     new Object[] {"bob","bradley","banana split","badgers"},
     new Object[] {"frank","felicity","fruit fly","eagles"},
     new Object[] {"frank","fredrick","fruitful","flyers"},
     new Object[] {"frank","fanny","fruition","76ers"},
});
ITreeContentProvider tree = new ListTreeContentProvider(list,
"#{row[1]}", "#{row[0]}", null);


Columns

You can add columns to the Tree control to display content for each tree row. Table columns, including special columns, like Select Row columns, work in Trees exactly the same as they do in Tables. Additionally, the Tree Toggle column controls allow users to toggle tree rows expanded and collapsed. Usually, each tree should include a Tree Toggle control.

You can sort columns by specifying a key using the column's sort property value. For more information, see the Standard Column control.

Children

javax.faces.Column, Basic Column control