mx.binding.utils.BindingUtils - Adobe® Flex® 4 Language Reference (Flex 4)

Package	mx.binding.utils
Class	public class BindingUtils
Inheritance	BindingUtils Object

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

The BindingUtils class defines utility methods for performing data binding from ActionScript. You can use the methods defined in this class to configure data bindings.

Public Properties

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	Property		Defined By
		constructor : Object A reference to the class object or constructor function for a given object instance.	Object
		prototype : Object [static] A reference to the prototype object of a class or function object.	Object

Public Methods

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	Method		Defined By
		bindProperty(site:Object, prop:String, host:Object, chain:Object, commitOnly:Boolean = false, useWeakReference:Boolean = false):ChangeWatcher [static] Binds a public property, prop on the site Object, to a bindable property or property chain.	BindingUtils
		bindSetter(setter:Function, host:Object, chain:Object, commitOnly:Boolean = false, useWeakReference:Boolean = false):ChangeWatcher [static] Binds a setter function, setter, to a bindable property or property chain.	BindingUtils
		hasOwnProperty(name:String):Boolean Indicates whether an object has a specified property defined.	Object
		isPrototypeOf(theClass:Object):Boolean Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter.	Object
		propertyIsEnumerable(name:String):Boolean Indicates whether the specified property exists and is enumerable.	Object
		setPropertyIsEnumerable(name:String, isEnum:Boolean = true):void Sets the availability of a dynamic property for loop operations.	Object
		toLocaleString():String Returns the string representation of this object, formatted according to locale-specific conventions.	Object
		toString():String Returns the string representation of the specified object.	Object
		valueOf():Object Returns the primitive value of the specified object.	Object

Method Detail

bindProperty

()

method

 public static function bindProperty(site:Object, prop:String, host:Object, chain:Object, commitOnly:Boolean = false, useWeakReference:Boolean = false):ChangeWatcher

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Binds a public property, prop on the site Object, to a bindable property or property chain. If a ChangeWatcher instance is successfully created, prop is initialized to the current value of chain.

Parameters

	`site:Object` — The Object defining the property to be bound to `chain`.

	`prop:String` — The name of the public property defined in the `site` Object to be bound. The property will receive the current value of `chain`, when the value of `chain` changes.

	`host:Object` — The object that hosts the property or property chain to be watched.

	`chain:Object` — A value specifying the property or chain to be watched. Legal values are: String containing the name of a public bindable property of the host object. An Object in the form: `{ name: property name, getter: function(host) { return host[property name] } }`. This Object must contain the name of, and a getter function for, a public bindable property of the host object. A non-empty Array containing a combination of the first two options that represents a chain of bindable properties accessible from the host. For example, to bind the property `host.a.b.c`, call the method as: `bindProperty(site, prop, host, ["a","b","c"])`. Note: The property or properties named in the `chain` argument must be public, because the `describeType()` method suppresses all information about non-public properties, including the bindability metadata that ChangeWatcher scans to find the change events that are exposed for a given property. However, the getter function supplied when using the `{ name, getter }` argument form described above can be used to associate an arbitrary computed value with the named (public) property.

	`commitOnly:Boolean` (default = `false`) — Set to `true` if the handler should be called only on committing change events; set to `false` if the handler should be called on both committing and non-committing change events. Note: the presence of non-committing change events for a property is indicated by the `[NonCommittingChangeEvent(<event-name>)]` metadata tag. Typically these tags are used to indicate fine-grained value changes, such as modifications in a text field prior to confirmation.

	`useWeakReference:Boolean` (default = `false`) — (default = false) Determines whether the reference to the host is strong or weak. A strong reference (the default) prevents the host from being garbage-collected. A weak reference does not.

Returns

ChangeWatcher — A ChangeWatcher instance, if at least one property name has been specified to the chain argument; null otherwise.

bindSetter

()

method

 public static function bindSetter(setter:Function, host:Object, chain:Object, commitOnly:Boolean = false, useWeakReference:Boolean = false):ChangeWatcher

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Binds a setter function, setter, to a bindable property or property chain. If a ChangeWatcher instance is successfully created, the setter function is invoked. The setter must have the following function signature:

      function mySetterFunction(object:Object):void {
          //Do whatever you want with the value of the bound property.
      }

where object contains the current value of chain.

Parameters

	`setter:Function` — Setter method to invoke with an argument of the current value of `chain` when that value changes.

	`host:Object` — The host of the property. See the `bindProperty()` method for more information.

	`chain:Object` — The name of the property, or property chain. See the `bindProperty()` method for more information.

	`commitOnly:Boolean` (default = `false`) — Set to `true` if the handler should be called only on committing change events. See the `bindProperty()` method for more information.

	`useWeakReference:Boolean` (default = `false`) — (default = false) Determines whether the reference to the host is strong or weak. A strong reference (the default) prevents the host from being garbage-collected. A weak reference does not.

Returns

ChangeWatcher — A ChangeWatcher instance, if at least one property name has been specified to the chain argument; null otherwise.