Attributes"

From Documentation
m
Line 19: Line 19:
  
 
There are a few ways to associate Java objects with EL expressions
 
There are a few ways to associate Java objects with EL expressions
# Implement a variable resolver (<javadoc type="interface">org.zkoss.xel.VariableResolver</javadoc> and specify it with the [[ZUML Reference/ZUML/Processing Instructions/variable-resolver|variable-resolver]] directive.
+
# Implement a variable resolver (<javadoc type="interface">org.zkoss.xel.VariableResolver</javadoc>) and specify it with the [[ZUML Reference/ZUML/Processing Instructions/variable-resolver|variable-resolver]] directive.
 
# Return the object in a static method and specify it in [[ZUML Reference/ZUML/Processing Instructions/xel-method|xel-method]]
 
# Return the object in a static method and specify it in [[ZUML Reference/ZUML/Processing Instructions/xel-method|xel-method]]
 
# Construct them in [[ZUML Reference/ZUML/Elements/zscript|zscript]]
 
# Construct them in [[ZUML Reference/ZUML/Elements/zscript|zscript]]

Revision as of 07:34, 15 November 2010



Each attribute, except special attributes like if and forEach, represents a value that shall be assigned to a property of a component after it is created. For example, when an attribute, say, foo</foo>, is specified, ZK Loader will assume there is a method called setFoo that accepts a single argument. If there are multiple methods with the same name, ZK Loader will use the one that matches the argument most (in term of the argument's class).

For example, suppose ${foo} is evaluated to an integer in the following example, ZK Loader will invoke Window.setMode(int), rather than Window.setMode(String).

<window mode="${foo}">
...

The values of attributes usually consist of EL expressions. For example,

<listbox forEach="${matrix}">
    <listitem label="${forEachStatus.previous.each.label}: ${each}" forEach=${each.items}/> <!-- nested-->
</listbox>

There are a few ways to associate Java objects with EL expressions

  1. Implement a variable resolver (VariableResolver) and specify it with the variable-resolver directive.
  2. Return the object in a static method and specify it in xel-method
  3. Construct them in zscript

In the following sections, we will discuss the special attributes one-by-one.





Last Update : 2010/11/15

Copyright © Potix Corporation. This article is licensed under GNU Free Documentation License.