com.vaadin.client

Class ResourceLoader

java.lang.Object

com.vaadin.client.ResourceLoader

public class ResourceLoader
extends Object

ResourceLoader lets you dynamically include external scripts and styles on the page and lets you know when the resource has been loaded. You can also preload resources, allowing them to get cached by the browser without being evaluated. This enables downloading multiple resources at once while still controlling in which order e.g. scripts are executed.

Since:

1.0

Author:

Vaadin Ltd

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ResourceLoader.ResourceLoadEvent Event fired when a resource has been loaded.
static interface	ResourceLoader.ResourceLoadListener Event listener that gets notified when a resource has been loaded.

Constructor Summary

Constructors

Constructor and Description
ResourceLoader(Registry registry, boolean initFromDom) Creates a new resource loader.

Method Summary

Modifier and Type	Method and Description
static void	addOnloadHandler(elemental.dom.Element element, ResourceLoader.ResourceLoadListener listener, ResourceLoader.ResourceLoadEvent event) Adds an onload listener to the given element, which should be a link or a script tag.
void	inlineHtml(String htmlContents, ResourceLoader.ResourceLoadListener resourceLoadListener) Inlines an HTML import and notify a listener when the HTML import is loaded.
void	inlineScript(String scriptContents, ResourceLoader.ResourceLoadListener resourceLoadListener) Inlines a script and notify a listener when the script is loaded.
void	inlineStyleSheet(String styleSheetContents, ResourceLoader.ResourceLoadListener resourceLoadListener) Inlines a stylesheet and notify a listener when the stylesheet is loaded.
void	loadHtml(String htmlUrl, ResourceLoader.ResourceLoadListener resourceLoadListener, boolean async) Loads an HTML import and notify a listener when the HTML import is loaded.
void	loadScript(String scriptUrl, ResourceLoader.ResourceLoadListener resourceLoadListener) Load a script and notify a listener when the script is loaded.
void	loadScript(String scriptUrl, ResourceLoader.ResourceLoadListener resourceLoadListener, boolean async, boolean defer) Load a script and notify a listener when the script is loaded.
void	loadStylesheet(String stylesheetUrl, ResourceLoader.ResourceLoadListener resourceLoadListener) Load a stylesheet and notify a listener when the stylesheet is loaded.
void	runWhenHtmlImportsReady(Runnable task) Sets the provided task to be run by HTMLImports.whenReady.

Methods inherited from class java.lang.Object

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

Constructor Detail

ResourceLoader

public ResourceLoader(Registry registry,
                      boolean initFromDom)

Creates a new resource loader. You should not create you own resource loader, but instead use Registry.getResourceLoader() to get an instance.

Parameters:

registry - the global registry

initFromDom - true if currently loaded resources should be marked as loaded, false to ignore currently loaded resources

Method Detail

loadScript

public void loadScript(String scriptUrl,
                       ResourceLoader.ResourceLoadListener resourceLoadListener)

Load a script and notify a listener when the script is loaded. Calling this method when the script is currently loading or already loaded doesn't cause the script to be loaded again, but the listener will still be notified when appropriate.

Loads all dependencies with async = false and defer = false attribute values, see loadScript(String, ResourceLoadListener, boolean, boolean).

Parameters:

scriptUrl - the url of the script to load

resourceLoadListener - the listener that will get notified when the script is loaded

loadScript

public void loadScript(String scriptUrl,
                       ResourceLoader.ResourceLoadListener resourceLoadListener,
                       boolean async,
                       boolean defer)

Load a script and notify a listener when the script is loaded. Calling this method when the script is currently loading or already loaded doesn't cause the script to be loaded again, but the listener will still be notified when appropriate.

Parameters:

scriptUrl - url of script to load

resourceLoadListener - listener to notify when script is loaded

async - What mode the script.async attribute should be set to

defer - What mode the script.defer attribute should be set to

inlineScript

public void inlineScript(String scriptContents,
                         ResourceLoader.ResourceLoadListener resourceLoadListener)

Inlines a script and notify a listener when the script is loaded. Calling this method when the script is currently loading or already loaded doesn't cause the script to be loaded again, but the listener will still be notified when appropriate.

Parameters:

scriptContents - the script contents to inline

resourceLoadListener - listener to notify when script is loaded

loadHtml

public void loadHtml(String htmlUrl,
                     ResourceLoader.ResourceLoadListener resourceLoadListener,
                     boolean async)

Loads an HTML import and notify a listener when the HTML import is loaded. Calling this method when the HTML import is currently loading or already loaded doesn't cause the HTML import to be loaded again, but the listener will still be notified when appropriate.

Parameters:

htmlUrl - url of HTML import to load

resourceLoadListener - listener to notify when the HTML import is loaded

async - loads the import asynchronously, if true, synchronously otherwise

inlineHtml

public void inlineHtml(String htmlContents,
                       ResourceLoader.ResourceLoadListener resourceLoadListener)

Inlines an HTML import and notify a listener when the HTML import is loaded. Calling this method when the HTML import is currently loading or already loaded doesn't cause the HTML import to be loaded again, but the listener will still be notified when appropriate.

Parameters:

htmlContents - the html contents to inline

resourceLoadListener - listener to notify when the HTML import is loaded

runWhenHtmlImportsReady

public void runWhenHtmlImportsReady(Runnable task)

Sets the provided task to be run by HTMLImports.whenReady. The task is run immediately if HTMLImports.whenReady is not supported.

Parameters:

task - the task to run, not null

addOnloadHandler

public static void addOnloadHandler(elemental.dom.Element element,
                                    ResourceLoader.ResourceLoadListener listener,
                                    ResourceLoader.ResourceLoadEvent event)

Adds an onload listener to the given element, which should be a link or a script tag. The listener is called whenever loading is complete or an error occurred.

Parameters:

element - the element to attach a listener to

listener - the listener to call

event - the event passed to the listener

loadStylesheet

public void loadStylesheet(String stylesheetUrl,
                           ResourceLoader.ResourceLoadListener resourceLoadListener)

Load a stylesheet and notify a listener when the stylesheet is loaded. Calling this method when the stylesheet is currently loading or already loaded doesn't cause the stylesheet to be loaded again, but the listener will still be notified when appropriate.

Parameters:

stylesheetUrl - the url of the stylesheet to load

resourceLoadListener - the listener that will get notified when the stylesheet is loaded

inlineStyleSheet

public void inlineStyleSheet(String styleSheetContents,
                             ResourceLoader.ResourceLoadListener resourceLoadListener)

Inlines a stylesheet and notify a listener when the stylesheet is loaded. Calling this method when the stylesheet is currently loading or already loaded doesn't cause the stylesheet to be loaded again, but the listener will still be notified when appropriate.

Parameters:

styleSheetContents - the contents to inline

resourceLoadListener - the listener that will get notified when the stylesheet is loaded