Automatic Data Binding
- 2 minutes to read
The ASPxTreeView control has a unique built-in ability to automatically retrieve data from a data source that supports the IHierarchicalEnumerable or IHierarchicalDataSource interface. This topic describes the conditions that let ASPxTreeView control bind to data after just one property (ASPxHierarchicalDataWebControl.DataSourceID or ASPxDataWebControlBase.DataSource) is specified.
The ASPxTreeView can recognize the data items and retrieve some node characteristics from the data fields named in a specific way. If however, any of the data-related properties of an ASPxTreeView control (such as ASPxTreeView.TextField, ASPxTreeView.ImageUrlField, etc.) have been set, then the mapping of the associated TreeViewNode object properties will proceed according to Data Binding Using Mapping Properties.
Data fields and node properties name match
During binding, an ASPxTreeView control implements its automatic binding ability by retrieving node characteristics from those data fields whose names coincide with certain property names of a TreeViewNode object. The table below lists the names of the node object properties that can be mapped during automatic binding, and the matching data field names you should use in the data source for the mapping to work.
| Node properties that can be set automatically | Data field names |
|---|---|
| TreeViewNode.Checked | Checked |
| TreeViewNode.Enabled | Enabled |
| TreeViewNode.Image.Url | ImageUrl |
| TreeViewNode.Name | Name |
| TreeViewNode.NavigateUrl | NavigateUrl |
| TreeViewNode.Target | Target |
| TreeViewNode.Text | Text |
| TreeViewNode.ToolTip | ToolTip |
The following image illustrates the process of data retrieval during automatic binding to a particular type of data source - XmlDataSource. Note, that only the DataSourceId property is set for the ASPxTreeView.
Binding to a Site Map
Since the properties of a SiteMapNode object have specific names, the ASPxTreeView is designed to automatically bind to a Site Map source, with node attributes with similar names. In the process of binding, corresponding properties of individual TreeViewNode objects are automatically associated with these item attributes and mapped accordingly. See the table below for name correspondence.
| Site Map node attributes | Corresponding TreeViewNode object properties |
|---|---|
| Description | TreeViewNode.ToolTip |
| Title | TreeViewNode.Text |
| Url | TreeViewNode.NavigateUrl |
Note
The structure of a Site Map allows flexibility in the naming of item attributes. After the ASPxTreeView detects the item attributes named title, url and description in the bound Site Map source, the conditions described in the above section apply.
ASPxTreeView control can bind to the Site Map via the SiteMapDataSource or the ASPxSiteMapDataSource control. The picture below demonstrates the process of data retrieval and TreeViewNode object property mapping, when binding via the ASPxSiteMapDataSource control.
