org.apache.myfaces.renderkit.html.util
Class DefaultAddResource

java.lang.Object
  org.apache.myfaces.renderkit.html.util.DefaultAddResource

All Implemented Interfaces:

AddResource

public class DefaultAddResource
extends java.lang.Object
implements AddResource

This is a utility class to render link to resources used by custom components. Mostly used to avoid having to include [script src="..."][/script] in the head of the pages before using a component.

When used together with the ExtensionsFilter, this class can allow components in the body of a page to emit script and stylesheet references into the page head section. The relevant methods on this object simply queue the changes, and when the page is complete the ExtensionsFilter calls back into this class to allow it to insert the commands into the buffered response.

This class also works with the ExtensionsFilter to allow components to emit references to javascript/css/etc which are bundled in the component's jar file. Special URLs are generated which the ExtensionsFilter will later handle by retrieving the specified resource from the classpath.

The special URL format is:

 {contextPath}/faces/myFacesExtensionResource/
    {resourceLoaderName}/{cacheKey}/{resourceURI}
 

Where:

• {contextPath} is the context path of the current webapp
• {resourceLoaderName} is the fully-qualified name of a class which implements the ResourceLoader interface. When a browser app sends a request for the specified resource, an instance of the specified ResourceLoader class will be created and passed the resourceURI part of the URL for resolving to the actual resource to be served back. The standard MyFaces ResourceLoader implementation only serves resources for files stored beneath path org/apache/myfaces/custom in the classpath but non-myfaces code can provide their own ResourceLoader implementations.

Version:

$Revision: 371739 373827 $ $Date: 2006-01-31 14:50:35 +0000 (Tue, 31 Jan 2006) $

Author:

Sylvain Vieujot (latest modification by $Author: mmarinschek $)

Nested Class Summary

protected static class	DefaultAddResource.AttributeInfo
protected static class	DefaultAddResource.ParseCallbackListener
protected static interface	DefaultAddResource.PositionedInfo
protected static interface	DefaultAddResource.WritablePositionedInfo

Field Summary

protected java.lang.String	_contextPath
protected int	afterBodyContentInsertPosition
protected int	beforeBodyEndPosition
protected int	beforeBodyPosition
protected int	bodyInsertPosition
protected int	headerInsertPosition
protected static org.apache.commons.logging.Log	log
protected boolean	parserCalled

Fields inherited from interface org.apache.myfaces.renderkit.html.util.AddResource

BODY_END, BODY_ONLOAD, HEADER_BEGIN

Constructor Summary

protected

DefaultAddResource()

Method Summary

void	addInlineScriptAtPosition(javax.faces.context.FacesContext context, ResourcePosition position, java.lang.String inlineScript) Adds the given Inline Script at the specified document position.
void	addInlineStyleAtPosition(javax.faces.context.FacesContext context, ResourcePosition position, java.lang.String inlineStyle) Adds the given Inline Style at the specified document position.
void	addJavaScriptAtPosition(javax.faces.context.FacesContext context, ResourcePosition position, java.lang.Class myfacesCustomComponent, java.lang.String resourceName) Insert a [script src="url"] entry into the document header at the specified document position.
void	addJavaScriptAtPosition(javax.faces.context.FacesContext context, ResourcePosition position, java.lang.Class myfacesCustomComponent, java.lang.String resourceName, boolean defer) Insert a [script src="url"] entry into the document header at the specified document position.
void	addJavaScriptAtPosition(javax.faces.context.FacesContext context, ResourcePosition position, ResourceHandler resourceHandler) Adds the given Javascript resource to the document header at the specified document positioy by supplying a resourcehandler instance.
void	addJavaScriptAtPosition(javax.faces.context.FacesContext context, ResourcePosition position, ResourceHandler resourceHandler, boolean defer) Adds the given Javascript resource at the specified document position.
void	addJavaScriptAtPosition(javax.faces.context.FacesContext context, ResourcePosition position, java.lang.String uri) Insert a [script src="url"] entry into the document header at the specified document position.
void	addJavaScriptAtPosition(javax.faces.context.FacesContext context, ResourcePosition position, java.lang.String uri, boolean defer) Adds the given Javascript resource at the specified document position.
void	addJavaScriptHere(javax.faces.context.FacesContext context, java.lang.Class myfacesCustomComponent, java.lang.String resourceName) Insert a [script src="url"] entry at the current location in the response.
void	addJavaScriptHere(javax.faces.context.FacesContext context, ResourceHandler resourceHandler) Insert a [script src="url"] entry at the current location in the response.
void	addJavaScriptHere(javax.faces.context.FacesContext context, java.lang.String uri) Insert a [script src="url"] entry at the current location in the response.
void	addJavaScriptToBodyTag(javax.faces.context.FacesContext context, java.lang.String javascriptEventName, java.lang.String addedJavaScript)
void	addResourceHere(javax.faces.context.FacesContext context, ResourceHandler resourceHandler)
void	addStyleSheet(javax.faces.context.FacesContext context, ResourcePosition position, java.lang.Class myfacesCustomComponent, java.lang.String resourceName) Adds the given Style Sheet at the specified document position.
void	addStyleSheet(javax.faces.context.FacesContext context, ResourcePosition position, ResourceHandler resourceHandler) Adds the given Style Sheet at the specified document position.
void	addStyleSheet(javax.faces.context.FacesContext context, ResourcePosition position, java.lang.String uri) Adds the given Style Sheet at the specified document position.
protected java.util.Set	getBodyEndInfos()
protected java.util.Set	getBodyOnloadInfos()
protected long	getCacheKey(javax.faces.context.FacesContext context) Return a value used in the {cacheKey} part of a generated URL for a resource reference.
protected java.util.Set	getHeaderBeginInfos()
protected java.lang.String	getResourceUri(javax.faces.context.FacesContext context, java.lang.Class resourceLoader, boolean withContextPath) Get the Path used to retrieve an resource.
java.lang.String	getResourceUri(javax.faces.context.FacesContext context, java.lang.Class myfacesCustomComponent, java.lang.String resource)
java.lang.String	getResourceUri(javax.faces.context.FacesContext context, java.lang.Class myfacesCustomComponent, java.lang.String resource, boolean withContextPath)
java.lang.String	getResourceUri(javax.faces.context.FacesContext context, ResourceHandler resourceHandler) Get the Path used to retrieve an resource.
java.lang.String	getResourceUri(javax.faces.context.FacesContext context, ResourceHandler resourceHandler, boolean withContextPath) Get the Path used to retrieve an resource.
java.lang.String	getResourceUri(javax.faces.context.FacesContext context, java.lang.String uri) Get the Path used to retrieve an resource.
java.lang.String	getResourceUri(javax.faces.context.FacesContext context, java.lang.String uri, boolean withContextPath) Get the Path used to retrieve an resource.
protected DefaultAddResource.PositionedInfo	getScriptInstance(javax.faces.context.FacesContext context, java.lang.String uri, boolean defer)
boolean	hasHeaderBeginInfos() check there is something to write to the header
boolean	isResourceUri(javax.servlet.http.HttpServletRequest request)
void	parseResponse(javax.servlet.http.HttpServletRequest request, java.lang.String bufferedResponse, javax.servlet.http.HttpServletResponse response) Parses the response to mark the positions where code will be inserted
void	serveResource(javax.servlet.ServletContext context, javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
void	setContextPath(java.lang.String contextPath) the context path for the web-app. You can set the context path only once, every subsequent set will throw an SecurityException
protected void	validateResourceHandler(ResourceHandler resourceHandler) Verify that the resource handler is acceptable.
protected void	validateResourceLoader(java.lang.Class resourceloader) Given a Class object, verify that the instances of that class implement the ResourceLoader interface.
void	writeMyFacesJavascriptBeforeBodyEnd(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Writes the javascript code necessary for myfaces in every page, just befode the closing </body> tag
void	writeResponse(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Writes the response
void	writeWithFullHeader(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Add the resources to the <head> of the page.

Methods inherited from class java.lang.Object

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

Field Detail

log

protected static final org.apache.commons.logging.Log log

_contextPath

protected java.lang.String _contextPath

parserCalled

protected boolean parserCalled

headerInsertPosition

protected int headerInsertPosition

bodyInsertPosition

protected int bodyInsertPosition

beforeBodyPosition

protected int beforeBodyPosition

afterBodyContentInsertPosition

protected int afterBodyContentInsertPosition

beforeBodyEndPosition

protected int beforeBodyEndPosition

Constructor Detail

DefaultAddResource

protected DefaultAddResource()

Method Detail

addJavaScriptHere

public void addJavaScriptHere(javax.faces.context.FacesContext context,
                              java.lang.Class myfacesCustomComponent,
                              java.lang.String resourceName)
                       throws java.io.IOException

Insert a [script src="url"] entry at the current location in the response. The resource is expected to be in the classpath, at the same location as the specified component + "/resource".

Example: when customComponent is class example.Widget, and resourceName is script.js, the resource will be retrieved from "example/Widget/resource/script.js" in the classpath.

Specified by:

addJavaScriptHere in interface AddResource

Throws:

java.io.IOException

addJavaScriptHere

public void addJavaScriptHere(javax.faces.context.FacesContext context,
                              java.lang.String uri)
                       throws java.io.IOException

Insert a [script src="url"] entry at the current location in the response.

Specified by:

addJavaScriptHere in interface AddResource

Parameters:

uri - is the location of the desired resource, relative to the base directory of the webapp (ie its contextPath).

Throws:

java.io.IOException

addJavaScriptHere

public void addJavaScriptHere(javax.faces.context.FacesContext context,
                              ResourceHandler resourceHandler)
                       throws java.io.IOException

Insert a [script src="url"] entry at the current location in the response.

Specified by:

addJavaScriptHere in interface AddResource

Parameters:

context -

resourceHandler - is an object which specifies exactly how to build the url that is emitted into the script tag. Code which needs to generate URLs in ways that this class does not support by default can implement a custom ResourceHandler.

Throws:

java.io.IOException

addResourceHere

public void addResourceHere(javax.faces.context.FacesContext context,
                            ResourceHandler resourceHandler)
                     throws java.io.IOException

Specified by:

addResourceHere in interface AddResource

Throws:

java.io.IOException

validateResourceHandler

protected void validateResourceHandler(ResourceHandler resourceHandler)

Verify that the resource handler is acceptable. Null is not valid, and the getResourceLoaderClass method must return a Class object whose instances implements the ResourceLoader interface.

Parameters:

resourceHandler -

validateResourceLoader

protected void validateResourceLoader(java.lang.Class resourceloader)

Given a Class object, verify that the instances of that class implement the ResourceLoader interface.

Parameters:

resourceloader -

addJavaScriptAtPosition

public void addJavaScriptAtPosition(javax.faces.context.FacesContext context,
                                    ResourcePosition position,
                                    ResourceHandler resourceHandler)

Adds the given Javascript resource to the document header at the specified document positioy by supplying a resourcehandler instance.

Use this method to have full control about building the reference url to identify the resource and to customize how the resource is written to the response. In most cases, however, one of the convenience methods on this class can be used without requiring a custom ResourceHandler to be provided.

If the script has already been referenced, it's added only once.

Note that this method queues the javascript for insertion, and that the script is inserted into the buffered response by the ExtensionsFilter after the page is complete.

Specified by:

addJavaScriptAtPosition in interface AddResource

addJavaScriptAtPosition

public void addJavaScriptAtPosition(javax.faces.context.FacesContext context,
                                    ResourcePosition position,
                                    java.lang.Class myfacesCustomComponent,
                                    java.lang.String resourceName)

Insert a [script src="url"] entry into the document header at the specified document position. If the script has already been referenced, it's added only once.

The resource is expected to be in the classpath, at the same location as the specified component + "/resource".

Example: when customComponent is class example.Widget, and resourceName is script.js, the resource will be retrieved from "example/Widget/resource/script.js" in the classpath.

Specified by:

addJavaScriptAtPosition in interface AddResource

addJavaScriptAtPosition

public void addJavaScriptAtPosition(javax.faces.context.FacesContext context,
                                    ResourcePosition position,
                                    java.lang.Class myfacesCustomComponent,
                                    java.lang.String resourceName,
                                    boolean defer)

Insert a [script src="url"] entry into the document header at the specified document position. If the script has already been referenced, it's added only once.

Specified by:

addJavaScriptAtPosition in interface AddResource

Parameters:

defer - specifies whether the html attribute "defer" is set on the generated script tag. If this is true then the browser will continue processing the html page without waiting for the specified script to load and be run.

addJavaScriptAtPosition

public void addJavaScriptAtPosition(javax.faces.context.FacesContext context,
                                    ResourcePosition position,
                                    java.lang.String uri)

Insert a [script src="url"] entry into the document header at the specified document position. If the script has already been referenced, it's added only once.

Specified by:

addJavaScriptAtPosition in interface AddResource

Parameters:

uri - is the location of the desired resource, relative to the base directory of the webapp (ie its contextPath).

addJavaScriptAtPosition

public void addJavaScriptAtPosition(javax.faces.context.FacesContext context,
                                    ResourcePosition position,
                                    java.lang.String uri,
                                    boolean defer)

Adds the given Javascript resource at the specified document position. If the script has already been referenced, it's added only once.

Specified by:

addJavaScriptAtPosition in interface AddResource

addJavaScriptToBodyTag

public void addJavaScriptToBodyTag(javax.faces.context.FacesContext context,
                                   java.lang.String javascriptEventName,
                                   java.lang.String addedJavaScript)

Specified by:

addJavaScriptToBodyTag in interface AddResource

addJavaScriptAtPosition

public void addJavaScriptAtPosition(javax.faces.context.FacesContext context,
                                    ResourcePosition position,
                                    ResourceHandler resourceHandler,
                                    boolean defer)

Adds the given Javascript resource at the specified document position. If the script has already been referenced, it's added only once.

Specified by:

addJavaScriptAtPosition in interface AddResource

addStyleSheet

public void addStyleSheet(javax.faces.context.FacesContext context,
                          ResourcePosition position,
                          java.lang.Class myfacesCustomComponent,
                          java.lang.String resourceName)

Adds the given Style Sheet at the specified document position. If the style sheet has already been referenced, it's added only once.

Specified by:

addStyleSheet in interface AddResource

addStyleSheet

public void addStyleSheet(javax.faces.context.FacesContext context,
                          ResourcePosition position,
                          java.lang.String uri)

Adds the given Style Sheet at the specified document position. If the style sheet has already been referenced, it's added only once.

Specified by:

addStyleSheet in interface AddResource

addStyleSheet

public void addStyleSheet(javax.faces.context.FacesContext context,
                          ResourcePosition position,
                          ResourceHandler resourceHandler)

Adds the given Style Sheet at the specified document position. If the style sheet has already been referenced, it's added only once.

Specified by:

addStyleSheet in interface AddResource

addInlineStyleAtPosition

public void addInlineStyleAtPosition(javax.faces.context.FacesContext context,
                                     ResourcePosition position,
                                     java.lang.String inlineStyle)

Adds the given Inline Style at the specified document position.

Specified by:

addInlineStyleAtPosition in interface AddResource

addInlineScriptAtPosition

public void addInlineScriptAtPosition(javax.faces.context.FacesContext context,
                                      ResourcePosition position,
                                      java.lang.String inlineScript)

Adds the given Inline Script at the specified document position.

Specified by:

addInlineScriptAtPosition in interface AddResource

getResourceUri

public java.lang.String getResourceUri(javax.faces.context.FacesContext context,
                                       java.lang.Class myfacesCustomComponent,
                                       java.lang.String resource,
                                       boolean withContextPath)

Specified by:

getResourceUri in interface AddResource

getResourceUri

public java.lang.String getResourceUri(javax.faces.context.FacesContext context,
                                       java.lang.Class myfacesCustomComponent,
                                       java.lang.String resource)

Specified by:

getResourceUri in interface AddResource

getResourceUri

public java.lang.String getResourceUri(javax.faces.context.FacesContext context,
                                       ResourceHandler resourceHandler)

Get the Path used to retrieve an resource.

Specified by:

getResourceUri in interface AddResource

getResourceUri

public java.lang.String getResourceUri(javax.faces.context.FacesContext context,
                                       ResourceHandler resourceHandler,
                                       boolean withContextPath)

Get the Path used to retrieve an resource.

Specified by:

getResourceUri in interface AddResource

getResourceUri

public java.lang.String getResourceUri(javax.faces.context.FacesContext context,
                                       java.lang.String uri)

Get the Path used to retrieve an resource.

Specified by:

getResourceUri in interface AddResource

getResourceUri

public java.lang.String getResourceUri(javax.faces.context.FacesContext context,
                                       java.lang.String uri,
                                       boolean withContextPath)

Get the Path used to retrieve an resource.

Specified by:

getResourceUri in interface AddResource

getResourceUri

protected java.lang.String getResourceUri(javax.faces.context.FacesContext context,
                                          java.lang.Class resourceLoader,
                                          boolean withContextPath)

Get the Path used to retrieve an resource.

getCacheKey

protected long getCacheKey(javax.faces.context.FacesContext context)

Return a value used in the {cacheKey} part of a generated URL for a resource reference.

Caching in browsers normally works by having files served to them include last-modified and expiry-time http headers. Until the expiry time is reached, a browser will silently use its cached version. After the expiry time, it will send a "get if modified since {time}" message, where {time} is the last-modified header from the version it has cached.

Unfortunately this scheme only works well for resources represented as plain files on disk, where the webserver can easily and efficiently see the last-modified time of the resource file. When that query has to be processed by a servlet that doesn't scale well, even when it is possible to determine the resource's last-modified date from servlet code.

Fortunately, for the AddResource class a static resource is only ever accessed because a URL was embedded by this class in a dynamic page. This makes it possible to implement caching by instead marking every resource served with a very long expiry time, but forcing the URL that points to the resource to change whenever the old cached version becomes invalid; the browser effectively thinks it is fetching a different resource that it hasn't seen before. This is implemented by embedding a "cache key" in the generated URL.

Rather than using the actual modification date of a resource as the cache key, we simply use the webapp deployment time. This means that all data cached by browsers will become invalid after a webapp deploy (all the urls to the resources change). It also means that changes that occur to a resource without a webapp redeploy will not be seen by browsers.

isResourceUri

public boolean isResourceUri(javax.servlet.http.HttpServletRequest request)

Specified by:

isResourceUri in interface AddResource

serveResource

public void serveResource(javax.servlet.ServletContext context,
                          javax.servlet.http.HttpServletRequest request,
                          javax.servlet.http.HttpServletResponse response)
                   throws java.io.IOException

Specified by:

serveResource in interface AddResource

Throws:

java.io.IOException

getHeaderBeginInfos

protected java.util.Set getHeaderBeginInfos()

getBodyEndInfos

protected java.util.Set getBodyEndInfos()

getBodyOnloadInfos

protected java.util.Set getBodyOnloadInfos()

hasHeaderBeginInfos

public boolean hasHeaderBeginInfos()

Description copied from interface: AddResource

check there is something to write to the header

Specified by:

hasHeaderBeginInfos in interface AddResource

parseResponse

public void parseResponse(javax.servlet.http.HttpServletRequest request,
                          java.lang.String bufferedResponse,
                          javax.servlet.http.HttpServletResponse response)

Parses the response to mark the positions where code will be inserted

Specified by:

parseResponse in interface AddResource

writeMyFacesJavascriptBeforeBodyEnd

public void writeMyFacesJavascriptBeforeBodyEnd(javax.servlet.http.HttpServletRequest request,
                                                javax.servlet.http.HttpServletResponse response)
                                         throws java.io.IOException

Writes the javascript code necessary for myfaces in every page, just befode the closing </body> tag

Specified by:

writeMyFacesJavascriptBeforeBodyEnd in interface AddResource

Throws:

java.io.IOException

writeWithFullHeader

public void writeWithFullHeader(javax.servlet.http.HttpServletRequest request,
                                javax.servlet.http.HttpServletResponse response)
                         throws java.io.IOException

Add the resources to the <head> of the page. If the head tag is missing, but the <body> tag is present, the head tag is added. If both are missing, no resource is added. The ordering is such that the user header CSS & JS override the MyFaces' ones.

Specified by:

writeWithFullHeader in interface AddResource

Throws:

java.io.IOException

writeResponse

public void writeResponse(javax.servlet.http.HttpServletRequest request,
                          javax.servlet.http.HttpServletResponse response)
                   throws java.io.IOException

Writes the response

Specified by:

writeResponse in interface AddResource

Throws:

java.io.IOException

getScriptInstance

protected DefaultAddResource.PositionedInfo getScriptInstance(javax.faces.context.FacesContext context,
                                                              java.lang.String uri,
                                                              boolean defer)

setContextPath

public void setContextPath(java.lang.String contextPath)

the context path for the web-app.
You can set the context path only once, every subsequent set will throw an SecurityException

Specified by:

setContextPath in interface AddResource