String value. Sets the id (or name) attribute of the rendered HTML tag. Note that the real id attribute rendered in the browser may be changed by the application container (for example, Portal containers may change the rendered id value to ensure the uniqueness of id's on the page). In this case, the real id rendered in the browser may be looked up through the JavaScript function lookupIdByTagId( tagId, tag ).

For example, assume that some tag's tagId attribute is set to foo.

    <netui:textBox tagId="foo" />

Then the following JavaScript function will return the real id attribute rendered in the browser:

    lookupIdByTagId( "foo", this )

To get a <netui:form> element and all of its children elements in JavaScript, use the same JavaScript function lookupIdByTagId( tagId, tag ). For example, assume that there is a <netui:form> whose tagId attribute is set to bar.

    <netui:form tagId="bar" >

Then the following JavaScript function will return the <netui:form> element and its children (packaged as an array).

    document[lookupIdByTagId( "bar", this )]

To retreive the value entered into a <netui:textBox> within the <netui:form> tag, use the following JavaScript expression.

    document[lookupIdByTagId("bar", this)][lookupIdByTagId("foo", this)].value

The second parameter ensures that the JavaScript function begins its search within the correct Portlet scope. Pass the JavaScript keyword this as the second parameter.