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mx.data 

DataService  - AS3 ADEP Data Services

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

Language Version: ActionScript 3.0
Product Version: Adobe Digital Enterprise Platform Data Services for Java EE 3
Runtime Versions: Flash Player 9, AIR 1.1

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

A DataService instance is constructed specifying the desired destination. Destinations are generally configured from the services-config.xml file, but can also be configured dynamically with runtime configuration, as in the case of model-driven development.

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.

For collection managed objects, you use the DataService.fill() method. This method populates an ArrayCollection with objects that this service manages.

To get single manged objects, use the DataService.getItem() and DataService.createItem() methods.

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

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

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

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

If a remote destination has declared any security constraints for an operation, you must provide credentials by calling the DataService.setCredentials() method. A call to the DataService.setCredentials() method turns into a login command at the remote destination. To change credentials or invalidate the current session, call the DataService.logout() method, which releases all local managed data. Calling the DataService.logout() method is equivalent to calling the DataService.release() method.

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

DataService and DataStore instances 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 instances share the same collection of managed objects and 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 still receives those events. Each operation you initiate on a DataService instance returns an AsyncToken instance. You can add an event responder to that AsyncToken instance to receive a result event specific to that operation. This approach often produces cleaner code than adding a result or fault event handler globally for a given destination.

You can use data binding on properties of any managed object for a DataService instance. A DataService instance also dispatches a "message" event when a remote operation occurs for any managed object. For example, when a remote process updates a locally managed item, a message is pushed to all DataService instances that are still managing that item. This message is dispatched as a MessageEvent.MESSAGE event.

A conflict event is dispatched when a conflict is detected either at the remote destination in response to a change the DataService instance commits or due to a pushed change that conflicts with a local uncommitted change. You can handle conflict events by listening for DataConflictEvent.CONFLICT. Use data binding to update user interface controls by binding to the DataService.conflicts.resolved property.

The DataService class supports the following data synchronization configuration modes:

  • autoCommit - when true each change is immediately sent to the remote destination when detected. When this is false, you must make an explicit call to the commit() method. Use the bindable DataService.commitRequired property determine if there are uncommitted changes.
  • autoSyncEnabled - This affects any fill(), getItem() or createItem() method calls and determines whether managed instances listen for changes made to these objects by other clients or by the DataServiceTransaction server push API at the remote destination.
  • autoMerge - Controls whether changes received from a remote destination are applied immediately or queued up until a call to the DataService.merge() method is made.

Use the DataService.revertChanges() method 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 data at the remote destination. If the changes are in error, you typically make a call to the DataService.revertChanges() method to undo the changes as part of a fault handler.

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

MXML SyntaxexpandedHide MXML Syntax

The <mx:DataService> element accepts the following 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."
 />
 

More examples

Related API Elements



Public Properties
 PropertyDefined By
 Inheritedadapter : DataServiceAdapter = null
An instance of a class that controls interaction with the server.
DataManager
 InheritedautoCommit : Boolean
Indicates whether 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
You can store the local cache of data and changes to disk.
DataManager
 InheritedautoSyncEnabled : Boolean
When true, fill(), createItem() and getItem() requests return items that 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 DataManager instance.
DataManager
 Inheritedconflicts : Conflicts
[read-only] Contains a Conflicts object, which is 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
 InheritedencryptLocalCache : Boolean
Indicates if offline storage should be encrypted For AIR clients that use a SQL offline adapter.
DataManager
 InheritedfallBackToLocalFill : Boolean
This flag determines whether the application should query against the local store when it is not connected.
DataManager
 InheritedhierarchicalEventsDefault : Boolean
Associations optionally list property change events on properties of the associated instances.
DataManager
 InheritedignoreCollectionUpdates : Boolean
Indicates if changes to managed collections should be ignored instead of being communicated to the server on a commit.
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 DataManager from association properties of other items.
DataManager
 InheritedisInitialized : Boolean
[read-only] Indicates whether the metadata associated with this DataManager instance is initialized.
DataManager
 InheritedmanualSync : ManualSyncConfiguration
Provides access to the ManualSyncConfiguration instance for each DataManager instance.
DataManager
 InheritedmaxFrequency : uint
Determines the maximum number of messages per second the DataManager instance can receive.
DataManager
 InheritedmergeRequired : Boolean
[read-only] Indicates whether there are any pending changes that must be merged.
DataManager
 InheritedofflineAdapter : DataServiceOfflineAdapter
Returns an object of type mx.data.DataServiceOfflineAdapter.
DataManager
 InheritedpageSize : int
Provides access to the current page size setting for all collections.
DataManager
 InheritedpagingEnabled : Boolean
[read-only] Indicates whether the remote destination is configured to allow paged requests.
DataManager
 Inheritedpriority : int
The default message priority for the messages the DataManager instance sends.
DataManager
 InheritedrequestTimeout : int
Provides access to the request timeout in seconds for an operation.
DataManager
 InheritedresetCollectionOnFill : Boolean
When the property is true, after the fill operation completes, a RESET event is sent.
DataManager
 InheritedresubscribeAttempts : int
Controls the number of times a disconnected DataManager instance attempts to resubscribe to its destination.
DataManager
 InheritedresubscribeInterval : int
Controls the delay, in milliseconds, between resubscribe attempts.
DataManager
 InheritedsaveCacheRequired : Boolean
[read-only] Indicates if there are changes that have not been saved to the local cache and the saveCache() method should be called.
DataManager
 Inheritedsubscribed : Boolean
[read-only] Indicates if the DataManager instance is subscribed to the remote destination.
DataManager
 InheritedthrowItemPendingErrors : Boolean
Set this property to false if you want to suppress item pending errors when lazily fetched or unpaged data is accessed.
DataManager
Public Methods
 MethodDefined By
  
DataService(destination:String)
Constructs a DataService instance with the specified destination.
DataService
 Inherited
Clears any data stored to disk with a previous call to the saveCache() method or when the autoSaveCache method 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 instance associated with this DataManager instance.
DataManager
 Inherited
Indicates if there are pending changes for this particular object.
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 DataManager instance'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 (collection) instance based on the associated fill method of the destination.
DataManager
 Inherited
Fills the specified ListCollectionView (collection) instance based on the associated fill method of the destination.
DataManager
 Inherited
findItem(queryName:String, propertySpecifier:PropertySpecifier, ... args):mx.rpc:AsyncToken
Executes a query that returns a single item.
DataManager
 Inherited
Returns an ArrayCollection or a single managed object from the the local store.
DataManager
 Inherited
Fills the specified ListCollectionView (collection) instance with CacheDataDescriptor instances.
DataManager
 Inherited
Fills the specified ListCollectionView (collection) instance 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
 Inherited
Fills the specified ListCollectionView based on the associated <fill-method> elements based on the data from the local store.
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 DataManager instance.
DataManager
 Inherited
Refreshes a 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 DataManager instance.
DataManager
 Inherited
releaseCollection(view:ListCollectionView, clear:Boolean = false, copyStillManagedItems:Boolean = true):void
Releases any item within the specified collection from management by this DataManager instance.
DataManager
 Inherited
releaseItem(item:IManaged, copyStillManagedItems:Boolean = true, enableStillManagedCheck:Boolean = true):IManaged
Releases the specified item from management by this DataManager instance.
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 DataManager instance.
DataManager
 Inherited
This method saves the current state of the DataManager instance's cache.
DataManager
 Inherited
Indicates if there are pending changes for this particular object that are not saved to the local 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
Obtains the changed items for all previously executed fills on this data service (data manager).
DataManager
 Inherited
[static] A convenience method to allow the synchronization of all local data: a synchronizeAllFills() is invoked on each data service (data manager) specified such that the final result token is completed only when all the individual synchronizeAllFills() calls are completed.
DataManager
 Inherited
Obtains the changed items that have changed on the server since the previous time a fill or synchronizeFill was invoked.
DataManager
 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 pending local changes and changes submitted by another client, or when changes submitted by this client conflict 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: Adobe Digital Enterprise Platform Data Services for Java EE 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: Adobe Digital Enterprise Platform Data Services for Java EE 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: Adobe Digital Enterprise Platform Data Services for Java EE 3
Runtime Versions: Flash Player 9, AIR 1.1

Constructs a DataService instance with the specified destination. The destination name must be a reference to a destination configured in a LiveCycle Data Service configuration file or with runtime configuration.

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: Adobe Digital Enterprise Platform Data Services for Java EE 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.

Related API Elements

setCredentials

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

Language Version: ActionScript 3.0
Product Version: Adobe Digital Enterprise Platform Data Services for Java EE 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: Adobe Digital Enterprise Platform Data Services for Java EE 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: Adobe Digital Enterprise Platform Data Services for Java EE 3
Runtime Versions: Flash Player 9, AIR 1.1

The DataConflictEvent.CONFLICT event is dispatched when a conflict is detected between pending local changes and changes submitted by another client, or when changes submitted by this client conflict with those in the remote destination. Each DataService instance 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: Adobe Digital Enterprise Platform Data Services for Java EE 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 also get this event for each item that generates an error as part of a commit result. In that case, the DataServiceFaultEvent contains the token returned by the commit, but the item and error message strings in the fault are specific to the item that 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

Language Version: ActionScript 3.0
Product Version: Adobe Digital Enterprise Platform Data Services for Java EE 3
Runtime Versions: Flash Player 9, AIR 1.1

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 instance.

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: Adobe Digital Enterprise Platform Data Services for Java EE 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: Adobe Digital Enterprise Platform Data Services for Java EE 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 the fill() method dispatches 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.