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GroupingCollection2

Package | mx.collections
Class | public class GroupingCollection2
Inheritance | GroupingCollection2 HierarchicalData flash.events.EventDispatcher
Implements | IGroupingCollection2

Language Version : | ActionScript 3.0

Product Version : | Flex 4

Runtime Versions : | Flash Player 10, AIR 1.5

The GroupingCollection2 class lets you create grouped data from flat data for display in the AdvancedDataGrid control. When you create the instance of the GroupingCollection2 from your flat data, you specify the field or fields of the data used to create the hierarchy.

Note: In the previous release of Flex, you used the GroupingCollection class with the AdvancedDataGrid control. The GroupingCollection2 class is new for Flex 4 and provides better performance than GroupingCollection.

To populate the AdvancedDataGrid control with grouped data, you create an instance of the GroupingCollection2 class from your flat data, and then pass that GroupingCollection2 instance to the data provider of the AdvancedDataGrid control. To specify the grouping fields of your flat data, you pass a Grouping instance to the `GroupingCollection2.grouping` property. The Grouping instance contains an Array of GroupingField instances, one per grouping field.

The following example uses the GroupingCollection2 class to define two grouping fields: Region and Territory.

      <mx:AdvancedDataGrid id="myADG"
        <mx:dataProvider>
          <mx:GroupingCollection2 id="gc" source="{dpFlat}">
            <mx:grouping>
              <mx:Grouping>
                <mx:GroupingField name="Region"/>
                <mx:GroupingField name="Territory"/>
              </mx:Grouping>
            </mx:grouping>
          </mx:GroupingCollection2>
        </mx:dataProvider>

        <mx:columns>
          <mx:AdvancedDataGridColumn dataField="Region"/>
          <mx:AdvancedDataGridColumn dataField="Territory"/>
          <mx:AdvancedDataGridColumn dataField="Territory_Rep"/>
          <mx:AdvancedDataGridColumn dataField="Actual"/>
          <mx:AdvancedDataGridColumn dataField="Estimate"/>
        </mx:columns>
      </mx:AdvancedDataGrid>

MXML Syntax Show MXML Syntax
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The `<mx.GroupingCollection2>` inherits all the tag attributes of its superclass, and defines the following tag attributes:

      <mx:GroupingCollection2
      Properties
        grouping="No default"
        source="No default"
        summaries="No default"
      />

Default MXML Property `grouping`

See also

mx.controls.AdvancedDataGrid
mx.collections.Grouping
mx.collections.GroupingField

Public Properties
Hide Inherited Public Properties
Show Inherited Public Properties

| Property | Defined By
--- | --- | ---
|  | childrenField : String Indicates the field name to be used to detect children objects in a data item. | HierarchicalData
|  | grouping : Grouping Specifies the Grouping instance applied to the source data. | GroupingCollection2
|  | source : Object [override] The source collection containing the flat data to be grouped. | GroupingCollection2
|  | summaries : Array Array of SummaryRow instances that define any root-level data summaries. | GroupingCollection2

Protected Properties

| Property | Defined By
--- | --- | ---
|  | timer : Timer The timer which is associated with an asynchronous refresh operation. | GroupingCollection2

Public Methods
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| Method | Defined By
--- | --- | ---
|  | GroupingCollection2() Constructor. | GroupingCollection2
|  | cancelRefresh():void If the refresh is performed asynchronously, cancels the refresh operation and stops the building of the groups. | GroupingCollection2
|  | canHaveChildren(node:Object):Boolean Returns true if the node can contain children. | HierarchicalData
|  | getChildren(node:Object):Object Returns an Object representing the node's children. | HierarchicalData
|  | getData(node:Object):Object Returns data from a node. | HierarchicalData
|  | getRoot():Object [override] Return super.source, if the grouping property is set, and an ICollectionView instance that refers to super.source if not. | GroupingCollection2
|  | hasChildren(node:Object):Boolean Returns true if the node has children. | HierarchicalData
|  | refresh(async:Boolean = false, dispatchCollectionEvents:Boolean = false):Boolean Applies the grouping to the collection. | GroupingCollection2

Protected Methods

| Method | Defined By
--- | --- | ---
|  | getParent(node:Object):* Returns the parent of a node. | GroupingCollection2

Property Detail

grouping | property

`grouping:Grouping`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 10, AIR 1.5

Specifies the Grouping instance applied to the source data. Setting the `grouping` property does not automatically refresh the view, so you must call the `refresh()` method after setting this property.

Implementation
`public function get grouping():Grouping`
`public function set grouping(value:Grouping):void`

See also

mx.collections.GroupingCollection2.refresh()

source | property |

`source:Object`[override]

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 10, AIR 1.5

The source collection containing the flat data to be grouped. If the source is not a collection, it will be auto-wrapped into a collection.

Implementation
`public function get source():Object`
`public function set source(value:Object):void`

summaries | property |

`public var summaries:Array`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 10, AIR 1.5

Array of SummaryRow instances that define any root-level data summaries. Specify one or more SummaryRow instances to define the data summaries, as the following example shows:

          <mx:AdvancedDataGrid id="myADG"
             width="100%" height="100%"
             initialize="gc.refresh();">
             <mx:dataProvider>
                 <mx:GroupingCollection2 id="gc" source="{dpFlat}">
                     <mx:summaries>
                         <mx:SummaryRow summaryPlacement="last">
                             <mx:fields>
                                 <mx:SummaryField2 dataField="Actual"
                                     label="Min Actual" summaryOperation="MIN"/>
                                 <mx:SummaryField2 dataField="Actual"
                                     label="Max Actual" summaryOperation="MAX"/>
                             </mx:fields>
                           </mx:SummaryRow>
                         </mx:summaries>
                     <mx:Grouping>
                         <mx:GroupingField name="Region"/>
                         <mx:GroupingField name="Territory"/>
                     </mx:Grouping>
                 </mx:GroupingCollection2>
             </mx:dataProvider>

             <mx:columns>
                 <mx:AdvancedDataGridColumn dataField="Region"/>
                 <mx:AdvancedDataGridColumn dataField="Territory_Rep"
                     headerText="Territory Rep"/>
                 <mx:AdvancedDataGridColumn dataField="Actual"/>
                 <mx:AdvancedDataGridColumn dataField="Estimate"/>
                 <mx:AdvancedDataGridColumn dataField="Min Actual"/>
                 <mx:AdvancedDataGridColumn dataField="Max Actual"/>
             </mx:columns>
          </mx:AdvancedDataGrid>

See also

mx.collections.SummaryRow
mx.collections.SummaryField2

timer | property |

`protected var timer:Timer`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 10, AIR 1.5

The timer which is associated with an asynchronous refresh operation. You can use it to change the timing interval, pause the refresh, or perform other actions. The default value for the `delay` property of the Timer instance is 1, corresponding to 1 millisecond.

Constructor Detail

GroupingCollection2 | () | Constructor

`public function GroupingCollection2()`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 10, AIR 1.5

Constructor.

Method Detail

cancelRefresh | () | method

`public function cancelRefresh():void`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 10, AIR 1.5

If the refresh is performed asynchronously, cancels the refresh operation and stops the building of the groups. This method only cancels the refresh if it is initiated by a call to the `refresh()` method with an `asynch` argument of `true`, corresponding to an asynchronous refresh.

getParent | () | method |

`protected function getParent(node:Object):*`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 10, AIR 1.5

Returns the parent of a node. The parent of a top-level node is `null`.

Parameters

| `node:Object` — The Object that defines the node.

Returns

| `*` — The parent node containing the node as child, `null` for a top-level node, and `undefined` if the parent cannot be determined.

getRoot | () | method |

`override public function getRoot():Object`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 10, AIR 1.5

Return `super.source`, if the `grouping` property is set, and an ICollectionView instance that refers to `super.source` if not.

Returns

| `Object` — The object to return.

refresh | () | method |

`public function refresh(async:Boolean = false, dispatchCollectionEvents:Boolean = false):Boolean`

Language Version : | ActionScript 3.0

Product Version : | Flex 3

Runtime Versions : | Flash Player 10, AIR 1.5

Applies the grouping to the collection. The collection does not detect changes to a group automatically, so you must call the `refresh()` method to update the collection after setting the `grouping`, `source`, or `summaries` properties. You also call the `refresh()` method when you modify a GroupingField of the collection, such as by changing the `caseInsensitive`, `compareFunction`, or `groupingFunction` properties.

The `refresh()` method can be applied synchronously or asynchronously.

When `refresh()` is called synchronously, all groups and summaries are updated together before the method returns. That means your application cannot perform other processing operations for the duration of the call. A client should wait for a CollectionEvent event with the value of the `kind` property set to `CollectionEventKind.REFRESH` to ensure that the `refresh()` method completed.

In asynchronous refresh, all groups and summaries are updated individually. The `refresh()` method returns before the groups and summaries are updated so that your application can continue execution. Also, the control is updated during the refresh so that the user can continue to interact with it.

The overhead of updating groups and summaries individually, rather than all at once, makes an asynchronous refresh take longer than a synchronous one. However, for large data sets, your application continues to operate during the refresh.

Parameters

| `async:Boolean` (default = `false`)`` — If `true`, defines the refresh to be asynchronous. By default it is `false` denoting synchronous refresh.
| `dispatchCollectionEvents:Boolean` (default = `false`)`` — If `true`, events are dispatched when groups are formed. For better performance, set it to `false`. If `true`, then events are dispatched as groups and summaries are calculated synchronously to update the control. Note: If `async` is `true`, the `dispatchCollectionEvents` is always set to `true`. By default it is `false` denoting no events will be dispatched.

Returns

| `Boolean` — `true` if the `refresh()` method completed, and `false` if the refresh is incomplete, which can mean that items are still pending.

Sun Mar 5 2017, 03:42 PM +11:00