org.omnifaces.resourcehandler

Class CombinedResourceHandler

java.lang.Object

javax.faces.application.ResourceHandler

javax.faces.application.ResourceHandlerWrapper

org.omnifaces.resourcehandler.DefaultResourceHandler

org.omnifaces.resourcehandler.CombinedResourceHandler

All Implemented Interfaces:

EventListener, FacesListener, SystemEventListener, FacesWrapper<ResourceHandler>

public class CombinedResourceHandler
extends DefaultResourceHandler
implements SystemEventListener

This ResourceHandler implementation will remove all separate script and stylesheet resources which have the target attribute set to "head" from the UIViewRoot and create a combined one for all scripts and another combined one for all stylesheets.

Installation

To get it to run, this handler needs be registered as follows in faces-config.xml:

 <application>
     <resource-handler>org.omnifaces.resourcehandler.CombinedResourceHandler</resource-handler>
 </application>
 

Usage

Noted shuold be that the target attribute of <h:outputStylesheet> already defaults to "head" but the one of <h:outputScript> not. So if you have placed this inside the <h:head>, then you would still need to explicitly set its target attribute to "head", otherwise it will be treated as an inline script and not be combined. This is a design limitation. This is not necessary for <o:deferredScript>.

 <h:head>
     ...
     <h:outputStylesheet name="style.css" />
     <h:outputScript name="script.js" target="head" />
     <o:deferredScript name="onload.js" />
 </h:head>
 

If you want them to appear after any auto-included resources of standard JSF implementation or JSF component libraries, then move the declarations to top of the <h:body>. This is not necessary for <o:deferredScript>.

 <h:body>
     <h:outputStylesheet name="style.css" />
     <h:outputScript name="script.js" target="head" />
     ...
 </h:body>
 

The generated combined resource URL also includes the "v" request parameter which is the last modified time of the newest individual resource in minutes, so that the browser will always be forced to request the latest version whenever one of the individual resources has changed.

Configuration

The following context parameters are available:

"org.omnifaces.COMBINED_RESOURCE_HANDLER_EXCLUDED_RESOURCES"	Comma separated string of resource identifiers of <h:head> resources which needs to be excluded from combining. For example: <param-value>primefaces:primefaces.css, javax.faces:jsf.js</param-value> Any combined resource will be included after any of those excluded resources.
"org.omnifaces.COMBINED_RESOURCE_HANDLER_SUPPRESSED_RESOURCES"	Comma separated string of resource identifiers of <h:head> resources which needs to be suppressed and removed. For example: <param-value>skinning.ecss, primefaces:jquery/jquery.js</param-value>
"org.omnifaces.COMBINED_RESOURCE_HANDLER_INLINE_CSS"	Set to true if you want to render the combined CSS resources inline (embedded in HTML) instead of as a resource.
"org.omnifaces.COMBINED_RESOURCE_HANDLER_INLINE_JS"	Set to true if you want to render the combined JS resources inline (embedded in HTML) instead of as a resource.

Here, the "resource identifier" is the unique combination of library name and resource name, separated by a colon, exactly the syntax as you would use in #{resource} in EL. If there is no library name, then just omit the colon. Valid examples of resource identifiers are filename.ext, folder/filename.ext, library:filename.ext and library:folder/filename.ext.

Note that this combined resource handler is not able to combine resources which are not been added as a component resource, but are been hardcoded in some renderer (such as theme.css in case of PrimeFaces and several JavaScript files in case of RichFaces), or are been definied using plain HTML <link> or <script> elements. Also, when you're using RichFaces with the context parameter org.richfaces.resourceOptimization.enabled set to true, then the to-be-combined resource cannot be resolved by a classpath URL due to RichFaces design limitations, so this combined resource handler will use an internal workaround to get it to work anyway, but this involves firing a HTTP request for every resource. The impact should however be relatively negligible as this is performed on localhost.

Conditionally disable combined resource handler

If you'd like to supply a context parameter which conditionally disables the combined resource handler, then set the context parameter "org.omnifaces.COMBINED_RESOURCE_HANDLER_DISABLED" accordingly.

 <context-param>
     <param-name>org.omnifaces.COMBINED_RESOURCE_HANDLER_DISABLED</param-name>
     <param-value>true</param-value>
 </context-param>
 <!-- or -->
 <context-param>
     <param-name>org.omnifaces.COMBINED_RESOURCE_HANDLER_DISABLED</param-name>
     <param-value>#{facesContext.application.projectStage eq 'Development'}</param-value>
 </context-param>
 <!-- or -->
 <context-param>
     <param-name>org.omnifaces.COMBINED_RESOURCE_HANDLER_DISABLED</param-name>
     <param-value>#{someApplicationScopedBean.someBooleanProperty}</param-value>
 </context-param>
 

The EL expression is resolved on a per-request basis.

CDNResourceHandler

If you're also using the CDNResourceHandler or, at least, have configured its context parameter "org.omnifaces.CDN_RESOURCE_HANDLER_URLS", then those CDN resources will automatically be added to the set of excluded resources.

Author:

Bauke Scholtz

See Also:

CombinedResource, CombinedResourceInfo, CombinedResourceInputStream, DefaultResource, DefaultResourceHandler

Field Summary

Fields

Modifier and Type	Field and Description
static String	LIBRARY_NAME The default library name of a combined resource.
static String	PARAM_NAME_DISABLED The context parameter name to conditionally disable combined resource handler.
static String	PARAM_NAME_EXCLUDED_RESOURCES The context parameter name to specify resource identifiers which needs to be excluded from combining.
static String	PARAM_NAME_INLINE_CSS The context parameter name to enable rendering CSS inline instead of as resource link.
static String	PARAM_NAME_INLINE_JS The context parameter name to enable rendering JS inline instead of as resource link.
static String	PARAM_NAME_SUPPRESSED_RESOURCES The context parameter name to specify resource identifiers which needs to be suppressed and removed.

Fields inherited from class javax.faces.application.ResourceHandler

LOCALE_PREFIX, RESOURCE_CONTRACT_XML, RESOURCE_EXCLUDES_DEFAULT_VALUE, RESOURCE_EXCLUDES_PARAM_NAME, RESOURCE_IDENTIFIER, WEBAPP_CONTRACTS_DIRECTORY_PARAM_NAME, WEBAPP_RESOURCES_DIRECTORY_PARAM_NAME

Constructor Summary

Constructors

Constructor and Description
CombinedResourceHandler(ResourceHandler wrapped) Creates a new instance of this combined resource handler which wraps the given resource handler.

Method Summary

Modifier and Type	Method and Description
Resource	createResource(String resourceName, String libraryName, String contentType) Delegate to the right createResource() method of the wrapped resource handler.
boolean	isListenerForSource(Object source) Returns true if the source is an instance of UIViewRoot.
void	processEvent(SystemEvent event) Before rendering of a freshly created view, perform the following actions: Collect all component resources from the head.

Methods inherited from class org.omnifaces.resourcehandler.DefaultResourceHandler

createResource, createResource, getWrapped

Methods inherited from class javax.faces.application.ResourceHandlerWrapper

createResourceFromId, createViewResource, getRendererTypeForResourceName, handleResourceRequest, isResourceRequest, isResourceURL, libraryExists

Methods inherited from class java.lang.Object

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

Field Detail

LIBRARY_NAME

public static final String LIBRARY_NAME

The default library name of a combined resource. Make sure that this is never used for other libraries.

See Also:

Constant Field Values

PARAM_NAME_DISABLED

public static final String PARAM_NAME_DISABLED

The context parameter name to conditionally disable combined resource handler. @since 2.0

See Also:

Constant Field Values

PARAM_NAME_EXCLUDED_RESOURCES

public static final String PARAM_NAME_EXCLUDED_RESOURCES

The context parameter name to specify resource identifiers which needs to be excluded from combining.

See Also:

Constant Field Values

PARAM_NAME_SUPPRESSED_RESOURCES

public static final String PARAM_NAME_SUPPRESSED_RESOURCES

The context parameter name to specify resource identifiers which needs to be suppressed and removed.

See Also:

Constant Field Values

PARAM_NAME_INLINE_CSS

public static final String PARAM_NAME_INLINE_CSS

The context parameter name to enable rendering CSS inline instead of as resource link.

See Also:

Constant Field Values

PARAM_NAME_INLINE_JS

public static final String PARAM_NAME_INLINE_JS

The context parameter name to enable rendering JS inline instead of as resource link.

See Also:

Constant Field Values

Constructor Detail

CombinedResourceHandler

public CombinedResourceHandler(ResourceHandler wrapped)

Creates a new instance of this combined resource handler which wraps the given resource handler. This will also register this resource handler as a pre render view event listener, so that it can do the job of removing the CSS/JS resources and adding combined ones.

Parameters:

wrapped - The resource handler to be wrapped.

Method Detail

isListenerForSource

public boolean isListenerForSource(Object source)

Returns true if the source is an instance of UIViewRoot.

Specified by:

isListenerForSource in interface SystemEventListener

processEvent

public void processEvent(SystemEvent event)
                  throws AbortProcessingException

Before rendering of a freshly created view, perform the following actions:

• Collect all component resources from the head.
• Check and collect the script and stylesheet resources separately and remove them from the head.
• If there are any resources in the collection of script and/or stylesheet resources, then create a component resource component pointing to the combined resource info and add it to the head at the location of the first resource.

Specified by:

processEvent in interface SystemEventListener

Throws:

AbortProcessingException

createResource

public Resource createResource(String resourceName,
                               String libraryName,
                               String contentType)

Description copied from class: DefaultResourceHandler

Delegate to the right createResource() method of the wrapped resource handler. Some resource handler implementations namely doesn't implement all the three createResource() methods.

Overrides:

createResource in class DefaultResourceHandler