dojo/Stateful (version 1.9)

Base class for objects that provide named properties with optional getter/setter control and the ability to watch for property changes

The class also provides the functionality to auto-magically manage getters and setters for object attributes/properties.

Getters and Setters should follow the format of _xxxGetter or _xxxSetter where the xxx is a name of the attribute to handle. So an attribute of "foo" would have a custom getter of _fooGetter and a custom setter of _fooSetter.

See the dojo/Stateful reference documentation for more information.

Examples

Example 1

var obj = new dojo.Stateful();
obj.watch("foo", function(){
    console.log("foo changed to " + this.get("foo"));
});
obj.set("foo","bar");

Property Summary

  • _attrPairNames Used across all instances a hash to cache attribute names and their getter and setter names.

Method Summary

  • _changeAttrValue(name, value) Internal helper for directly changing an attribute value.
  • _get(name, names) Private function that does a get based off a hash of names
  • _getAttrNames(name) Helper function for get() and set().
  • get(name) Get a property on a Stateful instance.
  • postscript(params)
  • set(name, value) Set a property on a Stateful instance
  • watch(name, callback) Watches a property for changes

Properties

_attrPairNames
Defined by: dojo/Stateful

Used across all instances a hash to cache attribute names and their getter and setter names.

Methods

_changeAttrValue(name, value)
Defined by dojo/Stateful

Internal helper for directly changing an attribute value.

Directly change the value of an attribute on an object, bypassing any accessor setter. Also handles the calling of watch and emitting events. It is designed to be used by descendent class when there are two values of attributes that are linked, but calling .set() is not appropriate.

Parameter Type Description
name String

The property to set.

value Mixed

The value to set in the property.

Returns: function

Internal helper for directly changing an attribute value.

_get(name, names)
Defined by dojo/Stateful

Private function that does a get based off a hash of names

Parameter Type Description
name undefined
names undefined

Hash of names of custom attributes

Returns: undefined
_getAttrNames(name)
Defined by dojo/Stateful

Helper function for get() and set(). Caches attribute name values so we don't do the string ops every time.

Parameter Type Description
name undefined
Returns: undefined | object
get(name)
Defined by dojo/Stateful

Get a property on a Stateful instance.

Get a named property on a Stateful object. The property may potentially be retrieved via a getter method in subclasses. In the base class this just retrieves the object's property. For example:

stateful = new dojo.Stateful({foo: 3});
stateful.get("foo") // returns 3
stateful.foo // returns 3
Parameter Type Description
name String

The property to get.

Returns: any | undefined

The property value on this Stateful instance.

postscript(params)
Defined by dojo/Stateful
Parameter Type Description
params Object
Optional
set(name, value)
Defined by dojo/Stateful

Set a property on a Stateful instance

Sets named properties on a stateful object and notifies any watchers of the property. A programmatic setter may be defined in subclasses. For example:

stateful = new dojo.Stateful();
stateful.watch(function(name, oldValue, value){
    // this will be called on the set below
}
stateful.set(foo, 5);

set() may also be called with a hash of name/value pairs, ex:

myObj.set({
    foo: "Howdy",
    bar: 3
})

This is equivalent to calling set(foo, "Howdy") and set(bar, 3)

Parameter Type Description
name String

The property to set.

value Object

The value to set in the property.

Returns: any | function

The function returns this dojo.Stateful instance.

watch(name, callback)
Defined by dojo/Stateful

Watches a property for changes

Parameter Type Description
name String
Optional

Indicates the property to watch. This is optional (the callback may be the only parameter), and if omitted, all the properties will be watched

callback Function

The function to execute when the property changes. This will be called after the property has been changed. The callback will be called with the |this| set to the instance, the first argument as the name of the property, the second argument as the old value and the third argument as the new value.

Returns: any | object

An object handle for the watch. The unwatch method of this object can be used to discontinue watching this property:

var watchHandle = obj.watch("foo", callback);
watchHandle.unwatch(); // callback won't be called now
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