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mx.data 
DataService 
Packagemx.data
Classpublic class DataService
InheritanceDataService Inheritance DataManager Inheritance Object
Subclasses DataService

Language Version: ActionScript 3.0
Product Version: LiveCycle Data Services 3
Runtime Versions: Flash Player 9, AIR 1.1

The DataService class provides the top-level functionality for Data Management Service. The DataService provides synchronization, replication, and occasionally connected services.

A DataService is constructed specifying the desired destination. These destinations are generally configured from the services-config.xml file.

There are two different sets of methods that retrieve data from the specified remote destination. The first are for collection managed objects. The second are for Single Managed Objects (SMOs).

For the collection managed objects the DataService.fill() method is used. This method populates an ArrayCollection with objects that this services will manage.

To get SMOs the DataService.getItem() and DataService.createItem() methods are used.

When a previously filled ArrayCollection is no longer needed, or the items within that collection should no longer receive or create updates, the DataService.releaseCollection() method is called.

When an item previously retrieved using DataService.getItem() or DataService.createItem() is no longer needed or should not receive or create updates, the DataService.releaseItem() method should be called. The DataService.createItem() and DataService.getItem() methods return an ItemReference. This object can be used to release a specific instance of a single managed object. Unlike the DataService.releaseItem() method, calling ItemReference.releaseItem() will release a specific instance of an SMO. DataService.releaseItem() will release the first SMO that it finds with a matching identity to that specified. This is normally okay as long as the number of calls to DataService.getItem() and DataService.createItem() matches the number of calls to DataService.releaseItem().

A connection to the remote destination is created automatically the first time any methods that require a connection are called. For example, calling the DataService.fill() method or DataService.commit() operation when there are uncommitted updates will attempt to establish a connection to the remote destination. To force a DataService to become disconnected use the DataService.disconnect() method. This method can be used to clean up remote destination resources when no longer needed. Because other services may be using the same physical connection calling DataService.disconnect() may terminate the connection.

The bindable property connected indicates the current state of the associated DataService connection.

If a remote destination has declared any security constraints for an operation, credentials must be provided. Credentials are set via the DataService.setCredentials() call. This turns into a login command at the remote destination. To change credentials or invalidate the current session DataService.logout() can be called. When called the DataService.logout() method will release all local managed data. It is equivalent to calling DataService.release().

Each DataService has a dataStore property that returns an object of type mx.data.DataStore. This object stores the uncommitted changes for one or more DataService objects. By default, a DataService shares the same DataStore with other data services if they have managed association properties and share the same set of channels. When sharing DataStores, a commit() method call on one DataService commits changes for all DataService using the shared data store. This preserves the order of operations in the event there are dependencies between the changes in the associated DataService objects.

DataService and DataStore dispatch result and fault events for all operations that require a remote call.

NOTE: if you create two DataService instances that point to the same destination both of those instances will share the same collection of managed objects, and will dispatch the same set of events. For example, if you add an event listener to one DataService instance for a destination, and you use a different instance to initiate an operation, the first DataService instance will still receive those events. Each operation you initiate on a DataService returns an AsyncToken. You can add an event responder to that token to receive a result event specific for that operation. This approach often produces cleaner code than adding a result or fault event handler globally for a given destination.

Data binding can be used on properties of any managed instances for a DataService. DataService will also dispatch a "message" event when a remote operation occurs for any managed object. For example when a locally managed item is updated by a remote process a message will be pushed to all DataService instances that are still managing that item. This message is dispatched as a MessageEvent.MESSAGE event.

When a conflict is detected either at the remote destination in response to a change committed by the DataService, or due to a pushed change which conflicts with a local uncommitted change, a conflict event is dispatched. These events can be handled by listening for the DataConflictEvent.CONFLICT. Data binding can be employed to update UI controls by binding to the DataService.conflicts.resolved property.

DataService supports the following data synchronization configuration modes:

  • autoCommit - when true each change is immediately sent to the remote destination once detected. When this is false, an explicit call to commit must be made. The bindable DataService.commitRequiredproperty can be used to determine whether or not there are uncommitted changes.
  • autoSyncEnabled - This affects any fill, getItem or createItem calls made and determines whether managed instances listen for changes made to these objects by other clients or using the server push api at the remote destination.
  • autoMerge property controls whether or not changes received from a remote destination are applied immediately or queued up until a call to DataService.merge() is made.

The DataService.revertChanges() method is used to revert changes for a specific item or for all items. When an error occurs for a remote destination operation, the committed changes are put back into the uncommitted queue so the data stays in sync with the remote destination data. If the changes are in error, typically a call to DataService.revertChanges() is made to undo the changes as part of a fault handler.

The mx.data.mxml.DataService class is an MXML-specific subclass of mx.data.DataService that allows binding to the properties of a DataService.

MXML SyntaxexpandedHide MXML Syntax

The <mx:DataService> tag accepts the following tag attributes:

  <mx:DataService
   Properties
   autoCommit="true"
   autoMerge="true"
   autoSaveCache="false"
   autoSyncEnabled="true"
   conflictDetector="No default."
   dataStore="No default."
   destination="No default."
   pageSize="No default."
   id="No default."
 
   Events
   conflict="No default."
   fault="No default."
   message="No default."
   propertyChange="No default."
   result="No default."
 />
 

See also



Public Properties
 PropertyDefined By
 Inheritedadapter : DataServiceAdapter = null
An instance of a class which controls interaction with the server.
DataManager
 InheritedautoCommit : Boolean
Indicates if changes to the local cache are automatically committed.
DataManager
 InheritedautoConnect : Boolean
Indicates if this service should attempt to connect for any operations that require a connection.
DataManager
 InheritedautoMerge : Boolean
If set to false, when changes are pushed from the remote destination to the client they are not immediately applied.
DataManager
 InheritedautoSaveCache : Boolean
The local cache of data and changes can be stored to disk.
DataManager
 InheritedautoSyncEnabled : Boolean
When true, fill(), createItem() and getItem() requests return items which listen for updates made to these items from the remote destination.
DataManager
 InheritedcacheID : String
Provides access to the cache identifier for this service.
DataManager
  channelSet : ChannelSet
Provides access to the ChannelSet used by the service.
DataService
 InheritedcommitRequired : Boolean
[read-only] Indicates if there are changes that have not been committed and the commit() method should be called.
DataManager
 InheritedconflictDetector : ConflictDetector
Provides access to the current implementation being used to detect conflicts for remote operations pushed to this DataService.
DataManager
 Inheritedconflicts : Conflicts
[read-only] Contains a Conflicts object, an ArrayList of Conflict instances.
DataManager
 Inheritedconnected : Boolean
[read-only] Indicates if the DataService is connected to the remote destination.
DataManager
 Inheritedconstructor : Object
A reference to the class object or constructor function for a given object instance.
Object
 InheriteddataStore : DataStore
Contains an object of type mx.data.DataStore.
DataManager
 InheriteddeleteItemOnRemoveFromFill : Boolean
By default when you call the removeItemAt() method on a managed filled collection, it issues a delete item call to the server to physically remove the item.
DataManager
  destination : String
[read-only] Indicates which remote destination this service is associated with.
DataService
 InheritedhierarchicalEventsDefault : Boolean
Associations optionally list for property change events on properties of the associated instances.
DataManager
 InheritedindexReferences : Boolean
To tune the speed of your application, set this property to false if you have a small number of fills or references to items managed by this data service from association properties of other items.
DataManager
 InheritedisInitialized : Boolean
[read-only] Indicates if the metadata associated with this service is initialized.
DataManager
 InheritedmanualSync : ManualSyncConfiguration
The manualSync property provides access to the ManualSyncConfiguration instance for each data service.
DataManager
 InheritedmaxFrequency : uint
Determines the maximum number of messages per second the DataManager wants to receive.
DataManager
 InheritedmergeRequired : Boolean
[read-only] Indicates if there are any pending changes that must be merged.
DataManager
 InheritedpageSize : int
Provides access to the current page size setting for all collections.
DataManager
 InheritedpagingEnabled : Boolean
[read-only] Indicates if the remote destination is configured to allow paged requests.
DataManager
 Inheritedpriority : int
The default message priority for the messages sent by the data service.
DataManager
 Inheritedprototype : Object
[static] A reference to the prototype object of a class or function object.
Object
 InheritedrequestTimeout : int
Provides access to the request timeout in seconds for an operation.
DataManager
 InheritedresetCollectionOnFill : Boolean
When true, after the fill operation completes, a RESET event is sent.
DataManager
 InheritedresubscribeAttempts : int
Controls the number of times a disconnected data service will attempt to resubscribe.
DataManager
 InheritedresubscribeInterval : int
Controls the delay, in milliseconds, between resubscribe attempts.
DataManager
 Inheritedsubscribed : Boolean
[read-only] Indicates if the DataService is subscribed to the remote destination.
DataManager
 InheritedthrowItemPendingErrors : Boolean
Set this property to false if you want to suppress the throwing of item pending errors when lazily fetched or unpaged data is accessed.
DataManager
Public Methods
 MethodDefined By
  
DataService(destination:String)
Constructs an instance of the DataService with the specified destination.
DataService
 Inherited
Clears any data stored to disk with a previous call to saveCache() or when autoSaveCache was set to true
DataManager
 Inherited
Clears the data specified by the passed descriptor from the local store.
DataManager
 Inherited
commit(itemsOrCollections:Array = null, cascadeCommit:Boolean = false):mx.rpc:AsyncToken
Commits pending changes for all collections currently managed by the DataStore associated with this data service.
DataManager
 Inherited
Forces a connection attempt by this service to the remote destination.
DataManager
 Inherited
Calls a count method on the remote destination.
DataManager
 Inherited
Requests that the specified item be created in the remote store.
DataManager
 Inherited
Requests that the specified item be deleted from the remote store.
DataManager
 Inherited
Disconnects the DataService's network connection.
DataManager
 Inherited
executeQuery(queryName:String, propertySpecifier:PropertySpecifier, ... args):mx.rpc:AsyncToken
Executes a query with the provided name and arguments.
DataManager
 Inherited
Fills the specified ListCollectionView based on the associated fill method of the destination.
DataManager
 Inherited
fillSubset(value:ListCollectionView, ps:PropertySpecifier, ... args):mx.rpc:AsyncToken
Fills the specified ListCollectionView based on the associated fill method of the destination.
DataManager
 Inherited
findItem(queryName:String, propertySpecifier:PropertySpecifier, ... args):mx.rpc:AsyncToken
Executes a query which returns a single item.
DataManager
 Inherited
Returns an ArrayCollection or a single managed object (SMO) from the the local store.
DataManager
 Inherited
This method will fill the specified ListCollectionView with CacheDataDescriptor(s).
DataManager
 Inherited
This method will fill the specified ListCollectionView with all cache identifiers previously used in the application.
DataManager
 Inherited
getItem(identity:Object, defaultValue:Object = null):ItemReference
Makes an asynchronous request for an item matching the specified identity.
DataManager
 Inherited
Looks up the supplied item with the given identity.
DataManager
 Inherited
Returns page information for the specified collection.
DataManager
 Inherited
Returns the pending operation in the message cache for the specified item.
DataManager
 Inherited
Indicates whether an object has a specified property defined.
Object
 Inherited
Forces initialization of the DataStore.
DataManager
 Inherited
Returns true if the passed collection is managed by this service.
DataManager
 Inherited
Returns true if the passed collection is using paging features.
DataManager
 Inherited
Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter.
Object
 Inherited
isRangeResident(view:ListCollectionView, startIndex:int, numberOfItems:int):Boolean
Returns true if the supplied range of items is all paged in.
DataManager
  
Logs the user out of the destination for the DataService.
DataService
 Inherited
Merges any pending updates into the managed set of objects.
DataManager
 Inherited
Indicates whether the specified property exists and is enumerable.
Object
 Inherited
Refreshes all data managed by this data service.
DataManager
 Inherited
Refreshes an array collection previously filled with the fill method or managed as a managed association.
DataManager
 Inherited
release(clear:Boolean = true, copyStillManagedItems:Boolean = true):void
Releases all managed collections and items for the DataService.
DataManager
 Inherited
releaseCollection(view:ListCollectionView, clear:Boolean = false, copyStillManagedItems:Boolean = true):void
Releases any item within the specified collection from management by this service.
DataManager
 Inherited
releaseItem(item:IManaged, copyStillManagedItems:Boolean = true, enableStillManagedCheck:Boolean = true):IManaged
Releases the specified item from management by this service.
DataManager
 Inherited
releaseItemsFromCollection(collection:ListCollectionView, startIndex:int, numberOfItems:int):int
Releases a range of items in the collection.
DataManager
 Inherited
Releases the value for a single-valued association.
DataManager
 Inherited
Reverts any uncommitted changes to the specified item.
DataManager
 Inherited
Reverts the changes for any item contained in the specified collection which should be managed by this data service.
DataManager
 Inherited
This method will save the current state of the DataService cache.
DataManager
  
setCredentials(username:String, password:String):void
Sets the credentials for this DataService destination.
DataService
 Inherited
Sets the availability of a dynamic property for loop operations.
Object
  
Sets the credentials for the third party of this DataService destination.
DataService
 Inherited
Returns the string representation of this object, formatted according to locale-specific conventions.
Object
 Inherited
Returns the string representation of the specified object.
Object
 Inherited
updateItem(item:Object, origItem:Object = null, changes:Array = null):mx.rpc:AsyncToken
Triggers an update for the specified item.
DataManager
 Inherited
Returns the primitive value of the specified object.
Object
Protected Methods
 MethodDefined By
 Inherited
Queues a fault if this data manager has not yet been initialized.
DataManager
Events
 Event Summary Defined By
  The DataConflictEvent.CONFLICT event is dispatched when a conflict is detected between either pending local changes and changes submitted by another client, or when changes submitted by this client are conflicting with those in the remote destination.DataService
  The DataServiceFaultEvent.FAULT event is dispatched when a service call fails due to an error.DataService
  The MessageEvent.MESSAGE event is dispatched when the remote destination pushes a notification of a data operation.DataService
  The PropertyChangeEvent.PROPERTY_CHANGE event is dispatched when a property of this service changes.DataService
  The ResultEvent.RESULT event is dispatched when a service call successfully returns.DataService
Property Detail

channelSet

property
channelSet:ChannelSet

Language Version: ActionScript 3.0
Product Version: LiveCycle Data Services 3
Runtime Versions: Flash Player 9, AIR 1.1

Provides access to the ChannelSet used by the service. The ChannelSet can be manually constructed and assigned, or it will be dynamically created to use the configured Channels for the destination for this service.



Implementation
    public function get channelSet():ChannelSet
    public function set channelSet(value:ChannelSet):void

destination

property 
destination:String  [read-only]

Language Version: ActionScript 3.0
Product Version: LiveCycle Data Services 3
Runtime Versions: Flash Player 9, AIR 1.1

Indicates which remote destination this service is associated with.



Implementation
    public function get destination():String
Constructor Detail

DataService

()Constructor
public function DataService(destination:String)

Language Version: ActionScript 3.0
Product Version: LiveCycle Data Services 3
Runtime Versions: Flash Player 9, AIR 1.1

Constructs an instance of the DataService with the specified destination. The destination must be a reference to a destination configured in the services-config.xml file.

Parameters
destination:String — that contains the name of the desired destination.
Method Detail

logout

()method
public function logout():void

Language Version: ActionScript 3.0
Product Version: LiveCycle Data Services 3
Runtime Versions: Flash Player 9, AIR 1.1

Logs the user out of the destination for the DataService. Logging out of a destination applies to everything connected using the same ChannelSet as specified in the server configuration. For example, if you are connected over the my-rtmp channel and you log out using one of your DataService instances, anything that was connected over the same ChannelSet is logged out.

Note: Adobe recommends that you use the mx.messaging.ChannelSet.logout() method rather than this method.

See also

setCredentials

()method 
public function setCredentials(username:String, password:String):void

Language Version: ActionScript 3.0
Product Version: LiveCycle Data Services 3
Runtime Versions: Flash Player 9, AIR 1.1

Sets the credentials for this DataService destination. The credentials are applied to all services connected over the same ChannelSet.

Parameters

username:String — The username for the destination.
 
password:String — The password for the destination

setRemoteCredentials

()method 
public function setRemoteCredentials(username:String, password:String):void

Language Version: ActionScript 3.0
Product Version: LiveCycle Data Services 3
Runtime Versions: Flash Player 9, AIR 1.1

Sets the credentials for the third party of this DataService destination.

Parameters

username:String — The username for the destination.
 
password:String — The password for the destination.

Event Detail

conflict

Event
Event Object Type: mx.data.events.DataConflictEvent
property DataConflictEvent.type = mx.data.events.DataConflictEvent.CONFLICT

Language Version: ActionScript 3.0
Product Version: LiveCycle Data Services 3
Runtime Versions: Flash Player 9, AIR 1.1

The DataConflictEvent.CONFLICT event is dispatched when a conflict is detected between either pending local changes and changes submitted by another client, or when changes submitted by this client are conflicting with those in the remote destination. Each DataService sends conflict events only for items of this particular destination. Use the conflict event on the DataService if you need to handle conflicts for a set of related destinations at the same time.

The CONFLICT constant defines the value of the type property of the event object for a conflict event.

The properties of the event object have the following values:

PropertyValue
bubblesfalse
cancelablefalse
currentTargetThe Object that defines the event listener that handles the event. For example, if you use myButton.addEventListener() to register an event listener, myButton is the value of the currentTarget.
conflict The Conflict object that holds the conflict that occurred.
message The Message associated with this event.
targetThe Object that dispatched the event; it is not always the Object listening for the event. Use the currentTarget property to always access the Object listening for the event.

fault

Event  
Event Object Type: mx.data.events.DataServiceFaultEvent
property DataServiceFaultEvent.type = mx.data.events.DataServiceFaultEvent.FAULT

Language Version: ActionScript 3.0
Product Version: LiveCycle Data Services 3
Runtime Versions: Flash Player 9, AIR 1.1

The DataServiceFaultEvent.FAULT event is dispatched when a service call fails due to an error. For example, a call to the fill() method dispatches this event if the call fails. You'll also get this event for each item which generates an error as part of a commit result. In this case, the DataServiceFaultEvent will contain the token returned by the commit, but the item and error message strings in the fault are specific to the item which caused the error.

The FAULT constant defines the value of the type property of the event object for a fault event.

The properties of the event object have the following values:

PropertyValue
bubblesfalse
cancelabletrue, calling preventDefault() from the associated token's responder.fault method will prevent the service or operation from dispatching this event
currentTargetThe Object that defines the event listener that handles the event. For example, if you use myButton.addEventListener() to register an event listener, myButton is the value of the currentTarget.
fault The Fault object that holds the conflict that occurred.
item The item that generated the fault.
identity The identity of of the item that generated the fault.
message The Message associated with this event.
token The token that represents the call to the method. Used in the asynchronous completion token pattern.
targetThe Object that dispatched the event; it is not always the Object listening for the event. Use the currentTarget property to always access the Object listening for the event.

message

Event  
Event Object Type: mx.messaging.events.MessageEvent
property MessageEvent.type = mx.messaging.events.MessageEvent.MESSAGE

The MessageEvent.MESSAGE event is dispatched when the remote destination pushes a notification of a data operation. For example, when data is updated in the remote destination an update operation is sent to all clients listening, this operation is converted to a message event on this DataService.

The MESSAGE event type; dispatched upon receipt of a message.

The value of this constant is "message".

The properties of the event object have the following values:

PropertyValue
bubblesfalse
cancelablefalse
currentTargetThe Object that defines the event listener that handles the event. For example, if you use myButton.addEventListener() to register an event listener, myButton is the value of the currentTarget.
messageThe message associated with this event.
targetThe Object that dispatched the event; it is not always the Object listening for the event. Use the currentTarget property to always access the Object listening for the event.

propertyChange

Event  
Event Object Type: mx.events.PropertyChangeEvent
property PropertyChangeEvent.type = mx.events.PropertyChangeEvent.PROPERTY_CHANGE

Language Version: ActionScript 3.0
Product Version: LiveCycle Data Services 3
Runtime Versions: Flash Player 9, AIR 1.1

The PropertyChangeEvent.PROPERTY_CHANGE event is dispatched when a property of this service changes. This happens for the following properties:

  • commitRequired
  • mergeRequired
  • connected

The PropertyChangeEvent.PROPERTY_CHANGE constant defines the value of the type property of the event object for a PropertyChange event.

The properties of the event object have the following values:

PropertyValue
bubblesDetermined by the constructor; defaults to false.
cancelableDetermined by the constructor; defaults to false.
kindThe kind of change; PropertyChangeEventKind.UPDATE or PropertyChangeEventKind.DELETE.
oldValueThe original property value.
newValueThe new property value, if any.
propertyThe property that changed.
sourceThe object that contains the property that changed.
currentTargetThe Object that defines the event listener that handles the event. For example, if you use myButton.addEventListener() to register an event listener, myButton is the value of the currentTarget.
targetThe Object that dispatched the event; it is not always the Object listening for the event. Use the currentTarget property to always access the Object listening for the event.

result

Event  
Event Object Type: mx.rpc.events.ResultEvent
property ResultEvent.type = mx.rpc.events.ResultEvent.RESULT

Language Version: ActionScript 3.0
Product Version: LiveCycle Data Services 3
Runtime Versions: Flash Player 9, AIR 1.1

The ResultEvent.RESULT event is dispatched when a service call successfully returns. For example a call to fill() will dispatch this event if the call is successful.

The RESULT event type.

The properties of the event object have the following values:

PropertyValue
bubblesfalse
cancelabletrue, preventDefault() from the associated token's responder.result method will prevent the service or operation from dispatching this event
currentTargetThe Object that defines the event listener that handles the event. For example, if you use myButton.addEventListener() to register an event listener, myButton is the value of the currentTarget.
message The Message associated with this event.
targetThe Object that dispatched the event; it is not always the Object listening for the event. Use the currentTarget property to always access the Object listening for the event.
resultResult that the RPC call returns.
tokenThe token that represents the indiviudal call to the method. Used in the asynchronous completion token pattern.