org.apache.tapestry5.internal.services.assets

Class CSSURLRewriter

java.lang.Object

org.apache.tapestry5.internal.services.assets.DelegatingSRS

org.apache.tapestry5.internal.services.assets.CSSURLRewriter

All Implemented Interfaces:

StreamableResourceSource

public class CSSURLRewriter
extends DelegatingSRS

Rewrites the url() attributes inside a CSS (MIME type "text/css")) resource. Each url is expanded to a complete path; this allows for CSS aggregation, where the location of the CSS file will change (which would ordinarily break relative URLs), and for changing the relative directories of the CSS file and the image assets it may refer to (useful for incorporating a hash of the resource's content into the exposed URL). One potential problem with URL rewriting is the way that URLs for referenced resources are generated; we are somewhat banking on the fact that referenced resources are non-compressable images.

Since:

5.4

See Also:

SymbolConstants.STRICT_CSS_URL_REWRITING

Field Summary

Fields inherited from class org.apache.tapestry5.internal.services.assets.DelegatingSRS

delegate

Constructor Summary

Constructors

Constructor and Description
CSSURLRewriter(StreamableResourceSource delegate, OperationTracker tracker, AssetSource assetSource, AssetChecksumGenerator checksumGenerator, boolean strictCssUrlRewriting)

Method Summary

Modifier and Type	Method and Description
StreamableResource	getStreamableResource(Resource baseResource, StreamableResourceProcessing processing, ResourceDependencies dependencies) Converts a Resource (which must be non-null and exist) into a streamable resource, along with some additional optional behaviors.

Methods inherited from class org.apache.tapestry5.internal.services.assets.DelegatingSRS

fileExtensionsForContentType

Methods inherited from class java.lang.Object

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

Constructor Detail

CSSURLRewriter

public CSSURLRewriter(StreamableResourceSource delegate,
                      OperationTracker tracker,
                      AssetSource assetSource,
                      AssetChecksumGenerator checksumGenerator,
                      boolean strictCssUrlRewriting)

Method Detail

getStreamableResource

public StreamableResource getStreamableResource(Resource baseResource,
                                                StreamableResourceProcessing processing,
                                                ResourceDependencies dependencies)
                                         throws IOException

Description copied from interface: StreamableResourceSource

Converts a Resource (which must be non-null and exist) into a streamable resource, along with some additional optional behaviors.

Specified by:

getStreamableResource in interface StreamableResourceSource

Overrides:

getStreamableResource in class DelegatingSRS

Parameters:

baseResource - the resource to convert

processing - defines additional processing after the resource has been read and possibly transformed

dependencies - Passed to any ResourceTransformer to track additional dependencies of the base resource

Returns:

the contents of the Resource, possibly transformed, in a streamable format.

Throws:

IOException - if the resource does not exist or a URL for the content is not available