ro.isdc.wro.model.resource.processor.impl.css

Class CssDataUriPreProcessor

java.lang.Object

ro.isdc.wro.model.resource.processor.impl.css.AbstractCssUrlRewritingProcessor

ro.isdc.wro.model.resource.processor.impl.css.CssDataUriPreProcessor

All Implemented Interfaces:

ImportAware, ResourcePostProcessor, ResourcePreProcessor

Direct Known Subclasses:

DuplicatesAwareCssDataUriPreProcessor, FallbackCssDataUriProcessor

public class CssDataUriPreProcessor
extends AbstractCssUrlRewritingProcessor

Rewrites background images by replacing the url with data uri of the image. If the replacement is not successful, it is left unchanged.

Attention: This processor should be added before CssUrlRewritingProcessor, otherwise the url's won't be replaced. For more details, @see DataUri Scheme on Wikipedia

Author:

Alex Objelean

Field Summary

Fields

Modifier and Type	Field and Description
static String	ALIAS

Constructor Summary

Constructors

Constructor and Description
CssDataUriPreProcessor()

Method Summary

Methods

Modifier and Type	Method and Description
protected DataUriGenerator	getDataUriGenerator()
protected boolean	isReplaceAccepted(String dataUri) Similar to isReplaceAccepted(String), but decides whether the computed dataUri should replace the image url.
protected boolean	isReplaceNeeded(String url) Check if url must be replaced or not.
protected String	replaceImageUrl(String cssUri, String imageUrl) Replace provided url with the new url if needed.

Methods inherited from class ro.isdc.wro.model.resource.processor.impl.css.AbstractCssUrlRewritingProcessor

getUrlPrefix, isImportAware, newCssUrlInspector, onProcessCompleted, onUrlReplaced, process, process, replaceDeclaration

Methods inherited from class java.lang.Object

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

Field Detail

ALIAS

public static final String ALIAS

See Also:

Constant Field Values

Constructor Detail

CssDataUriPreProcessor

public CssDataUriPreProcessor()

Method Detail

replaceImageUrl

protected String replaceImageUrl(String cssUri,
                     String imageUrl)

Replace provided url with the new url if needed.

Specified by:

replaceImageUrl in class AbstractCssUrlRewritingProcessor

Parameters:

imageUrl - to replace.

cssUri - Uri of the parsed css.

Returns:

replaced url.

isReplaceAccepted

protected boolean isReplaceAccepted(String dataUri)

Similar to isReplaceAccepted(String), but decides whether the computed dataUri should replace the image url. It is useful when you want to limit the dataUri size. By default the size of dataUri is limited to 32KB (because IE8 has a 32KB limitation).

Parameters:

dataUri - base64 encoded stream.

Returns:

true if dataUri should replace original image url.

isReplaceNeeded

protected boolean isReplaceNeeded(String url)

Check if url must be replaced or not. The replacement is not needed if the url of the image is absolute (can be resolved by urlResourceLocator) or if the url is a data uri (base64 encoded value).

Overrides:

isReplaceNeeded in class AbstractCssUrlRewritingProcessor

Parameters:

url - to check.

Returns:

true if url needs to be replaced or remain unchanged.

getDataUriGenerator

protected DataUriGenerator getDataUriGenerator()

Returns:

the DataUriGenerator class responsible for transforming streams into base64 encoded strings.