How to lookup values
A lookup dialog is an HTML page dialog that can be configured to opened for a simpeType element.
Built-in panels vs a custom lookup dialog
In the Content Editor interface, insert panels are used to lookup values from the Content Manager CMS, for such things as reuse content and images. The built-in library panels cannot be configured or extended.
If you want to use a customized lookup dialog in your application, you'll need to build it yourself.
Simple lookup configuration
First, you need to choose your target element or attribute. A common target is a required attribute on an element. This does not mean that you cannot lookup values for elements, but doing that is more complicated.
A simple lookup configuration uses the lookup configuration element. A link element in the XML has the attribute
href. We'll configure the lookup for @href as follows:
<x:node match="link/@href">
<x:lookup url="lookup-link-target.php" autoOpen="true"/>
</x:node>When the link element is inserted, Content Editor will validate the element and add the attribute. Now the editor will open the lookup page. The html lookup page takes care of the interaction with the user so that the user can select the desired value. The lookup has access to Content Editor through several means, and can return a value to the editor through the top.choose method.