Package com.sencha.gxt.data.shared.loader

Class Loader<C,M>

java.lang.Object

com.sencha.gxt.data.shared.loader.Loader<C,M>

Type Parameters:

C - the type of the data used to configure

M - the type of data being returned by the loader

All Implemented Interfaces:

BeforeLoadEvent.HasBeforeLoadHandlers<C>, LoaderHandler.HasLoaderHandlers<C,M>, LoadExceptionEvent.HasLoadExceptionHandlers<C>, LoadHandler.HasLoadHandlers<C,M>

Direct Known Subclasses:

ListLoader, TreeLoader

public class Loader<C,M>
extends Object
implements LoaderHandler.HasLoaderHandlers<C,M>

Abstract base class for objects that can load remote data.

The optional input object passed with the load request is logically called a "load config" with the object returned by the loader called the "load result".

Typically, loaders work with DataProxy and DataReader to help perform the load operations. The DataProxy is responsible for obtaining the remote data. The DataReader is responsible for "processing" the remote data and converting the data to the expected format.

Events:

BeforeLoadEvent

LoadEvent

LoadExceptionEvent

Constructor Summary

Constructors

Constructor	Description
Loader(DataProxy<C,M> proxy)	Creates a new base loader instance.
Loader(DataProxy<C,T> proxy, DataReader<M,T> reader)	Creates a new loader with the given proxy and reader.

Method Summary

Modifier and Type	Method	Description
com.google.gwt.event.shared.HandlerRegistration	addBeforeLoadHandler(BeforeLoadEvent.BeforeLoadHandler<C> handler)	Adds a BeforeLoadEvent handler.
com.google.gwt.event.shared.HandlerRegistration	addLoaderHandler(LoaderHandler<C,M> handler)	Adds a LoadEvent handler.
com.google.gwt.event.shared.HandlerRegistration	addLoadExceptionHandler(LoadExceptionEvent.LoadExceptionHandler<C> handler)	Adds a LoadExceptionEvent handler.
com.google.gwt.event.shared.HandlerRegistration	addLoadHandler(LoadHandler<C,M> handler)	Adds a LoadEvent handler.
C	getLastLoadConfig()	Returns the last load config.
DataProxy<?,?>	getProxy()	Returns the loader's data proxy.
boolean	isReuseLoadConfig()	Returns true if the load config is being reused.
boolean	load()	Loads the data using the current configuration.
boolean	load(C loadConfig)	Loads the data using the given load configuration.
void	setReuseLoadConfig(boolean reuseLoadConfig)	Sets whether the same load config instance should be used for load operations (defaults to false).

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Loader

public Loader(DataProxy<C,M> proxy)

Creates a new base loader instance. Since a data reader is not used, the data returned by the data proxy will not be read and converted by a reader.

Parameters:

proxy - the data proxy

Loader

public Loader(DataProxy<C,T> proxy,
              DataReader<M,T> reader)

Creates a new loader with the given proxy and reader.

Type Parameters:

T - the type of data being proxied

Parameters:

proxy - the data proxy

reader - the data reader

Method Detail

addBeforeLoadHandler

public com.google.gwt.event.shared.HandlerRegistration addBeforeLoadHandler(BeforeLoadEvent.BeforeLoadHandler<C> handler)

Description copied from interface: BeforeLoadEvent.HasBeforeLoadHandlers

Adds a BeforeLoadEvent handler.

Specified by:

addBeforeLoadHandler in interface BeforeLoadEvent.HasBeforeLoadHandlers<C>

Parameters:

handler - the handler

Returns:

the registration for the event

addLoaderHandler

public com.google.gwt.event.shared.HandlerRegistration addLoaderHandler(LoaderHandler<C,M> handler)

Description copied from interface: LoaderHandler.HasLoaderHandlers

Adds a LoadEvent handler.

Specified by:

addLoaderHandler in interface LoaderHandler.HasLoaderHandlers<C,M>

Parameters:

handler - the handler

Returns:

the registration for the event

addLoadExceptionHandler

public com.google.gwt.event.shared.HandlerRegistration addLoadExceptionHandler(LoadExceptionEvent.LoadExceptionHandler<C> handler)

Description copied from interface: LoadExceptionEvent.HasLoadExceptionHandlers

Adds a LoadExceptionEvent handler.

Specified by:

addLoadExceptionHandler in interface LoadExceptionEvent.HasLoadExceptionHandlers<C>

Parameters:

handler - the handler

Returns:

the registration for the event

addLoadHandler

public com.google.gwt.event.shared.HandlerRegistration addLoadHandler(LoadHandler<C,M> handler)

Description copied from interface: LoadHandler.HasLoadHandlers

Adds a LoadEvent handler.

Specified by:

addLoadHandler in interface LoadHandler.HasLoadHandlers<C,M>

Parameters:

handler - the handler

Returns:

the registration for the event

getLastLoadConfig

public C getLastLoadConfig()

Returns the last load config.

Returns:

the last load config

getProxy

public DataProxy<?,?> getProxy()

Returns the loader's data proxy.

Returns:

the data proxy

isReuseLoadConfig

public boolean isReuseLoadConfig()

Returns true if the load config is being reused.

Returns:

the reuse load config state

load

public boolean load()

Loads the data using the current configuration. Fires the BeforeLoadEvent before the request, then the LoadEvent after the load operation.

Returns:

true if the load was requested, false if cancelled

load

public boolean load(C loadConfig)

Loads the data using the given load configuration. Fires the BeforeLoadEvent before the request, then the LoadEvent after the load operation. The current load configuration object can be retrieved using getLastLoadConfig().

Parameters:

loadConfig - the load config

Returns:

true if the load was requested, false if cancelled

setReuseLoadConfig

public void setReuseLoadConfig(boolean reuseLoadConfig)

Sets whether the same load config instance should be used for load operations (defaults to false).

Parameters:

reuseLoadConfig - true to reuse