Called when a client adds an item to a filled collection.

You can use this method to track changes made to a filled collection by client applications. Usually the results of a fill are maintained by a query made on the server and so changes made by the client are temporary or replaced when the server has a chance to update the fill based on reexecuting the query. In some cases though, you may want to turn auto-refresh off for the fill, and track the changes made by the client to the filled collection. You might do this if the list of items returned for a given fill is maintained by an explicit list of object ids.

Warning: if you need clients to maintain a consistent order of items, you may not want to use this technique. If two clients insert different items into the same position at roughly the same time, each will have processed the inserts in different orders and so will have the two items swapped. You can ignore the position and maintain consistent lists where order is not critical or the client sorts the list.

Parameters

This method can be used to help control how fill methods are refreshed by Data Management Services. If this method returns true for a given set of fill parameters, it indicates that this fill method is to be auto-refreshed. In this mode, the Data Management Service calls your refreshFill method for each item of the appropriate type is created or updated. That method can determine whether or not we append this item to the existing list, re-execute the fill method, remove the item from the existing list, or do nothing. If this method always returns false, your refreshFill method is not called. In this case, you either use the DataServiceTransaction.refreshFill method to manually cause the fill to be reexecuted or you can let the clients changes to the fill update the assembler and other clients.

Parameters

Retrieve the number of items for a given query with the supplied parameters. This method is only necessary if your client code uses the corresponding count method on the DataService class.

When paging is enabled and this method is defined to return -1 , the client will be sent the number of records for the given query dynamically with each page request. This allows you to avoid an expensive count query for large data sets.

Parameters

Creates the item. Often, you fill in the identity properties unless those values were supplied by the client. If any errors occur for this operation, you can throw an exception of your choice to indicate that fact. The message of the exception is delivered to the client.

The Java class of the item supplied depends on the ActionScript class used by your client application. ActionScript to Java rules are by default used to convert the client object into a Java object. This will produce a java.util.Map for the item parameter if the client object is dynamic object or if that object does not have a RemoteClass alias mapping it to a Java class. If your assembler expects instances of a single specific Java class, you can use the item-class tag in your destination's configuration to specify a single class of which all java.util.Map instances are converted into before being passed to the assembler.

Parameters

This is called when the client application removes an item managed by the destination corresponding to this assembler. In this case, your deleteItem method is called with the version of the item intended for removal on the client. This method can do conflict detection to ensure that the item has not been modified since this deletion event was scheduled. In this case, your deleteItem method can throw the flex.data.DataSyncException where it should provide the current version of the item as the serverVersion parameter.

This method can also thrown any runtime exception to indicate a general error to be returned to the client.

If your object model uses properties which are load-on-demand or using page-size on the association tag, these properties are not included in the version of the item supplied as the previous version.

Parameters

This method is called by the Data Management Service for any fill methods called by the client which are not configured in the configuration file explicitly using the fill-method tag. If you have a matching fill-method definition for a given set of parameters, it is called instead of calling this method.

In general a fill method corresponds to a database query made on the server. The results of a fill method should be based solely on the parameters provided here - do not return different results of a fill for the same parameter set since Data Management Services is designed to try and keep all clients which use the same set of fill parameters viewing the same results.

Depending upon the number and type of fill method you need for this destination, it can be a good practice to use the first parameter as the name of the fill and the rest as the parameters to make it easier to identify the particular fill you are dealing with.

Parameters

This method is called by the Data Management Service for any paged-fill methods. A paged-fill method is called to satisfy fill and page requests from the client when paging is enabled for the given destination. This method will be used when a paged-fill method is not configured in the configuration file explicitly using the paged fill-method child tag of the fill-method tag. If you have a matching paged-fill-method definition for a given set of parameters, it is called instead of calling this method.

This method corresponds to a fill method with the same parameter list. Its benefit is improved performance in that it only retrieves a page of records instead of the entire set.

This default implementation calls the correspoding fill method. This will forego any performance gain and return the entire cillection.

Parameters

Retrieves an item with the specified Map of ids. Ids are stored with the key as the property name of the id property, the value as the value of the identity property.

Parameters

Retrieves a specific subset of properties for the item identified. The PropertySpecifier argument provides an interface to determine which properties should be retrieved. The rest of the properties are not used in the returned instance and so do not need to be populated.

Parameters

Given a list of identity Maps, returns the list of items. The list should contain null entries for any ids which do not map to a valid item. This is an optimization for the case where the getItem method needs to be called repeatedly to retrieve a list of items.

Parameters

This method can be used to return collection properties page-by-page rather than all at once. If this method returns null, the getItem method is called to retrieve the entire property value.

Parameters

When you set paged-collection=true on multi-valued association property, this method is used to determine the size of the returned collection. If this method returns -1, the collection's size is determined using a dynamic sizing approach. The client sees the collection's size as one more than the last page requested. When that item is fetched another page is requested. When the assembler returns fewer items from the getPagedCollectionProperty method, the size of the collection is known.

Parameters

If your fill methods are auto-refreshed, this method is called for each item that changes (either created or updated as indicated by the isCreate parameter). It can return DO_NOT_EXECUTE_FILL if you want to leave the contents of the fill unchanged, EXECUTE_FILL if you want the data service to call your fill method, or APPEND_TO_FILL if you just want this changed item to be added onto the end of the list returned by the last fill invocation.

Parameters

Called when a client removes an item from a filled collection. Like addItemToFill, you can use this method to monitor and record changes made by a client to a given filled collection.

Parameters

When the client is using pagedUpdates for updating a collection property, when those changes are committed to the server, this method is used by the assembler to update the collection property. The UpdateCollectionChanges method contains the identities of the objects to insert and remove from the collection along with positions in the collection for these operations (used for ordered collections).

Parameters

Updates the item. The newVersion is always going to be present and contains the new version of the item. The previousVersion contains any state required for maintaining the integrity of this instance. Currently, it is always fully populated. However, in the future, Adobe anticipates this method to selectively include only the properties of the item required to maintain an item's integrity during an update. It might be null to disable optimistic concurrency detection.

The changes array provides the list of properties changed. You should interpret a null value as "any properties may have changed". If you have a property which has its own properties, only the top level property name will be included.

If the previousVersion conflicts with the current database copy of the item, you can throw a flex.data.DataSyncException to indicate this fact. In this case, you should provide the current version of the item in the database as the serverVersion parameter. This allows the client to resolve the conflict and resubmit a non-conflicting change or revert to the server's version. Your method can also throw any runtime exception to indicate that a general fault has occurred while processing this update.

Your updateItem method can modify changes sent in from the client and add additional properties. To do this you update properties in the newVersion and add additional property names to the changes property.

The Java class of the items supplied depends on the ActionScript class used by your client application. ActionScript to Java rules are by default used to convert the client object into a Java object. This will produce a java.util.Map for the item parameter if the client object is dynamic object or if that object does not have a RemoteClass alias mapping it to a Java class. If your assembler expects instances of a single specific Java class, you can use the item-class tag in your destination's configuration to specify a single class of which all java.util.Map instances are converted into before being passed to the assembler.

If your object model uses properties which are load-on-demand or using page-size on the association tag, these properties are only included in the previous and new versions of the item if they are in the changes list. Otherwise, you can assume those properties have not changed.

Parameters

This method can be used to control whether a paged-fill method for a given set of parameters is used. This method will be called whenever paging is enabled and a client issues either a FILL or a PAGE request. If this method returns true, the paged-fill method will be called. If it returns false, the standard fill method will be called.

Parameters

Constant used as the return value from the refreshFill method. APPEND_TO_FILL tells Data Management Services to add this item onto the set of items in this filled collection if it is not already in the collection.

Constant used as the return value from the refreshFill method. DO_NOT_EXECUTE_FILL tells Data Management Services not to execute the fill method for this newly updated or created item.

Constant used as the return value from the refreshFill method. EXECUTE_FILL tells Data Management Services to reexecute the fill method for this newly updated or created item.

Constant used as the return value from the refreshFill method. REMOVE_FROM_FILL tells Data Management Services to remove this item from the set of items in this filled collection if it is in the collection.