Binding

Kind of class:class
Inherits from:none
Classpath:mx.data.binding.Binding
File last modified:Tuesday, 18 December 2007, 15:44:38
Defines an association between two endpoints, a source and a destination.
The Binding object listens for changes to the source endpoint, and copies the
data to the destination endpoint each time the source changes.

Summary


Constructor
  • Binding (source:Object, dest:Object, format:Object, is2way:Boolean)
    • Initializes a new Binding object.
Class properties
Instance properties
Class methods
Instance methods

Constructor

Binding

function Binding (
source:Object, dest:Object, format:Object, is2way:Boolean)

Initializes a new Binding object. Registers the Binding
as a listener for the 'data changed' event of the source endpoint.
Parameters:
source:
The source endpoint of the binding. This parameter is nominally of type
"EndPoint", but in fact it can be any actionscript object that has the required fields.
dest :
The destination endpoint of the binding. This
must not be a constant. The 'event' field of the destination is only
needed if the binding is 2-way.
format:
[optional] An object containing formatting information. The properties of this object are:


cls : class
an actionscript class which implements the interface mx.data.binding.Formatter.

className : String
a string containing the name of an actionscript class which implements the interface mx.data.binding.Formatter

settings : Object
an object whose properties are option settings for the formatter

cls and className contain the same information, and you can give one or the other of these, but not both.
The difference is that cls is an actual reference to the class, whereas className is the name of
the class as a string. If you choose to give the class name as a string, you must also reference that class directly somewhere
in actionscript code - this reminds Flash to include a copy of the class in your SWF. Examples:

{cls: com.mycompany.MyFormatter, settings: {precision: 3, separator: ","}}
{className: "com.mycompany.MyFormatter", settings: {precision: 3, separator: ","}}
is2way:
[optional] A boolean which is true if the binding is bi-directional.
Returns:
  • The Binding object that was just created. You don't need to keep a reference to
    this object - it will keep itself alive as long as needed.

    Warning: after creating a Binding, do not modify the fields of the objects
    that were passed as parameters to the constructor. The results will be unpredictable.

Example:
  • new Binding (
    {constant: "abc123"}, 
    {component: _root.Screen1.serviceCall1, property: "params", location: "password"});

foo = new Binding (
    {component: myServiceCall1, property: "results", event: "result"},
    {component: myDisplayText1, property: "text"},
    {cls: com.mycompany.SpecialFormatter},
    true);

src = new mx.data.binding.EndPoint();
src.component = myXmlDocument;
src.property = "results";
src.event = "result";
new mx.data.binding.Binding (src, {component: myComboBox, property: "dataProvider"});
src.location = "something"; // This line won't work! Do it *before* calling 'new Binding'

Class properties

bindingRegistry

static bindingRegistry:Array = new Array()
(read)

counter

static private counter:Number = 0
(read)

screenRegistry

static private screenRegistry:Object = new Object()
(read)

Instance properties

dest

dest:EndPoint
(read)

dispatchEvent

private dispatchEvent:Function
(read)

format

private format:Formatter
(read)

is2way

private is2way:Boolean
(read)

num

private num:Number
(read)

queued

private queued:Boolean = false
(read)

reverse

private reverse:Boolean = false
(read)

source

source:EndPoint
(read)

sub

private sub:Array
(read)

Class methods

copyBinding

static private function copyBinding (
b:mx = .data.binding.Binding)

copyEndPoint

static private function copyEndPoint (
e:mx = .data.binding.EndPoint)

dispatchEnterFrame

static private function dispatchEnterFrame (
)

getLocalRoot

static function getLocalRoot (
clip)

getRuntimeObject

static function getRuntimeObject (
info:Object, constructorParameter:Object)

okToCallGetterFromSetter

static function okToCallGetterFromSetter (
)

refreshDestinations

static function refreshDestinations (
component:Object, bindings:Array)

refreshFromSources

static function refreshFromSources (
component:Object, property:String, bindings:Array) : Array

registerBinding

static function registerBinding (
binding)

registerScreen

static function registerScreen (
screen, id)

Instance methods

calcShortLoc

private function calcShortLoc (
endpoint)

execute

function execute (
reverse:Boolean) : Array

Fetches the data from the source, formats it, and assigns it to the destination.
Validates the data and causes either a 'valid' or 'invalid' event to be emitted by
the destination and source components. Data is assigned to the destination even
if its invalid, unless the destination is read-only.
Parameters:
reverse:
A boolean which is true if the binding is to be executed in the
reverse direction (dest -> source).
Returns:
  • any error messages that were generated as a result of the assignment. These are either

queueForExecute

private function queueForExecute (
reverse)

Queues the binding for execution at a safe time.
Returns:
  • none

setUpIndexListeners

private function setUpIndexListeners (
endpoint, reverse)

if there are components which are indexes for this endpoint,
set up a listener so that we can re-evaluate the binding
when the index changes.

setUpListener

private function setUpListener (
endpoint, reverse)

summaryString

private function summaryString (
reverse:Boolean)