org.omnifaces.resourcehandler.SourceMapResourceHandler Maven / Gradle / Ivy
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/*
* Copyright OmniFaces
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
* an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
* specific language governing permissions and limitations under the License.
*/
package org.omnifaces.resourcehandler;
import static org.omnifaces.util.Faces.getInitParameterOrDefault;
import static org.omnifaces.util.Utils.endsWithOneOf;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import jakarta.faces.application.Resource;
import jakarta.faces.application.ResourceHandler;
import jakarta.faces.application.ResourceWrapper;
/**
*
* This {@link ResourceHandler} implementation will set the SourceMap response header with the correctly
* mapped request path to any discovered source map of any CSS and JS resource.
*
* By default, CSS and JS minifiers will embed the path to the source map in a comment like as the below one in our own
* omnifaces.js.
*
* //# sourceMappingURL=omnifaces.js.map
*
*
* The web browser will then attempt to resolve this against the current request URL, but this would fail with a 404
* error because the JSF mapping such as *.xhtml is missing.
*
* In order to sovle that, first configure your minifier to disable writing the # sourceMappingURL comment,
* otherwise that would still take precedence over the SourceMap response header, and register the
* {@link SourceMapResourceHandler} in faces-config.xml as below.
*
* <application>
* <resource-handler>org.omnifaces.resourcehandler.SourceMapResourceHandler</resource-handler>
* </application>
*
*
* By default, the {@link SourceMapResourceHandler} will use *.map pattern to create the source map URL.
* In other words, it's expected that the source map file is located in exactly the same folder and has the .map
* extension. In case you need a different pattern, e.g. sourcemaps/*.map, then you can set that via the
* {@value org.omnifaces.resourcehandler.SourceMapResourceHandler#PARAM_NAME_SOURCE_MAP_PATTERN} context parameter.
*
* <context-param>
* <param-name>org.omnifaces.SOURCE_MAP_RESOURCE_HANDLER_PATTERN</param-name>
* <param-value>sourcemaps/*.map</param-value>
* </context-param>
*
*
* Note that the SourceMap response header will only be set when the target source map file actually exists.
*
* @author Bauke Scholtz
* @since 3.1
*/
public class SourceMapResourceHandler extends DefaultResourceHandler {
/** The context parameter name to configure the source map pattern. */
public static final String PARAM_NAME_SOURCE_MAP_PATTERN =
"org.omnifaces.SOURCE_MAP_RESOURCE_HANDLER_PATTERN";
private static final Map SOURCE_MAPS = new ConcurrentHashMap<>();
private static final String DEFAULT_SOURCE_MAP_PATTERN = "*.map";
private static final String EXTENSION_JS = ".js";
private static final String EXTENSION_CSS = ".css";
private static final String HEADER_SOURCE_MAP = "SourceMap";
private String sourceMapPattern;
/**
* Creates a new instance of this source map resource handler which wraps the given resource handler.
* This will also initialize the source map pattern based on the context parameter.
* @param wrapped The resource handler to be wrapped.
*/
public SourceMapResourceHandler(ResourceHandler wrapped) {
super(wrapped);
sourceMapPattern = getInitParameterOrDefault(PARAM_NAME_SOURCE_MAP_PATTERN, DEFAULT_SOURCE_MAP_PATTERN);
}
@Override
public Resource decorateResource(Resource resource, String resourceName, String libraryName) {
if (resource == null) {
return null;
}
String sourceMap = SOURCE_MAPS.computeIfAbsent(new ResourceIdentifier(libraryName, resourceName), this::computeSourceMap);
return super.decorateResource(sourceMap.isEmpty() ? resource : new ResourceWrapper(resource) {
@Override
public Map getResponseHeaders() {
Map responseHeaders = super.getResponseHeaders();
responseHeaders.put(HEADER_SOURCE_MAP, sourceMap);
return responseHeaders;
}
}, resourceName, libraryName);
}
private String computeSourceMap(ResourceIdentifier resourceIdentifier) {
if (endsWithOneOf(resourceIdentifier.getName(), EXTENSION_JS, EXTENSION_CSS)) {
Resource sourceMapResource = createResource(sourceMapPattern.replace("*", resourceIdentifier.getName()), resourceIdentifier.getLibrary());
if (sourceMapResource != null) {
return sourceMapResource.getRequestPath();
}
}
return "";
}
}