.. _dijit/tree/TreeStoreModel:

dijit.tree.TreeStoreModel
=========================

The TreeStoreModel connects a data store with a single "root" item to a :ref:`dijit.Tree <dijit/Tree>`.

An example might be an employee database where the company's CEO is the root item, and all other
employees report directly or indirectly to the CEO.

Here's an example of a declarative initialization for a TreeStoreModel and for the data store that it connects to:

.. code-block :: html

	<div dojoType="dojo.data.ItemFileWriteStore" jsId="store"
		url="../tests/_data/treeTest.json"></div>
	<div dojoType="dijit.tree.TreeStoreModel" jsId="model"
		childrenAttrs="kids"
		store="store" query="{id:'root'}"></div>

A few things to note here:

  * The query {id:'root'}, when run against the data store, must return exactly one item
  * That item should have an attribute named "kids" with a list of children items


Here's a much more complicated where we've overridden the getChildren() method because in the
data store a child references it's parent rather than vice-versa.

.. code-block :: html

	<div dojoType="dijit.tree.TreeStoreModel" jsId="model" store="store">
		<script type="dojo/method" event="getChildren" args="item, onComplete">
			return store.fetch({query: {parent: store.getIdentity(item)}, onComplete: onComplete});
		</script>
		<script type="dojo/method" event="mayHaveChildren" args="item">
			var type = store.getValue(item, "type");
			return (type == "continent" || type == "country");
		</script>
	</div>