Client Attribute

Name: client attribute
Namespace: http://www.zkoss.org/2005/zk/client/attribute
Namespace shortcut: client/attribute
Java: LanguageDefinition.CLIENT_ATTRIBUTE_NAMESPACE

It is the reserved namespace for specifying client-side DOM attributes. Unlike the client namespace, which assigns something to widgets, the client/attribute namespace assigns additional DOM attributes to the DOM tree directly at the client.

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Notice that if the widget's DOM output (Widget.redraw(Array)) also has the same DOM attribute, both of them will be generated and it is technically not legal. Thus, you should prevent the DOM attributes that widget might output.

For example, suppose you want to listen to the onload event, you can do as follows.

<iframe src="http://www.google.com" width="100%" height="300px"
  xmlns:ca="client/attribute"
  ca:onload="do_whater_you_want()"/>

If the attribute contains colon or other special characters, you can use the attribute element as follows.

<div xmlns:ca="client/attribute">
  <attribute ca:name="ns:whatever">
  whatever_value_you_want
  </attribute>
</div>

The other use of the client-attribute namespace is to specify attributes that are available only to certain browsers, such as accessibility and Section 508.

Data-Attribute Handler

Developer can define their own data-handler for the client attribute to have an extra functionality. For example, (jQuery's mask)

Zul File:

<textbox xmlns:ca="client/attribute" ca:data-mask="00:00:00" onChange='Clients.log(self.value)'/>

zk.xml:

<client-config>	
	<data-handler>
		<name>mask</name><!-- the attribute name, i.e. data-mask -->
		<depends>http://igorescobar.github.io/jQuery-Mask-Plugin/js/jquery.mask.min.js</depends>
		<script>
		function (wgt, dataValue) {
			jq(wgt.$n()).mask(dataValue);

			// unformat after onChange event.
			wgt.listen({onChange: function (event) {
				event.data.value = jq(this.$n()).cleanVal();
			}});
		}
		</script>
	</data-handler>
</client-config>

Syntax Definition

• <data-handler>: a group of a data-attribute handler
  • <name>: the attribute name. (i.e. data-name)
  • <depends>: the url for extra JS files
  • <script> the script content
    • <script src="foo.js"> the src attribute for the script, it can be a url of a JS script from context-path or a url from class-path. For example,

      <script-uri>~./myscript</script-uri>

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Version History

Version	Date	Content
5.0.3	July 2010	The client-attribute namespace was introduced.
8.0.0	May 2015	Support client data attributes handler