/*
* Copyright 2013 Julien Dramaix.
*
* 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
*
* http://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 com.google.gwt.resources.gss;
import com.google.common.collect.ImmutableList;
import com.google.common.css.SourceCodeLocation;
import com.google.common.css.compiler.ast.CssFunctionArgumentsNode;
import com.google.common.css.compiler.ast.CssFunctionNode;
import com.google.common.css.compiler.ast.CssValueNode;
import com.google.common.css.compiler.ast.ErrorManager;
import com.google.common.css.compiler.ast.GssError;
import com.google.common.css.compiler.ast.GssFunction;
import com.google.common.css.compiler.ast.GssFunctionException;
import com.google.common.css.compiler.gssfunctions.GssFunctions;
import com.google.gwt.core.ext.typeinfo.JClassType;
import com.google.gwt.core.ext.typeinfo.JType;
import com.google.gwt.core.ext.typeinfo.NotFoundException;
import com.google.gwt.resources.client.DataResource;
import com.google.gwt.resources.client.ImageResource;
import com.google.gwt.resources.ext.ResourceContext;
import com.google.gwt.resources.ext.ResourceGeneratorUtil;
import com.google.gwt.resources.gss.ast.CssDotPathNode;
import com.google.gwt.resources.gss.ast.CssJavaExpressionNode;
import java.util.List;
public class ResourceUrlFunction implements GssFunction {
private final ResourceContext context;
private final JClassType dataResourceType;
private final JClassType imageResourceType;
public ResourceUrlFunction(ResourceContext context) {
this.context = context;
this.dataResourceType = context.getGeneratorContext().getTypeOracle()
.findType(DataResource.class.getCanonicalName());
this.imageResourceType = context.getGeneratorContext().getTypeOracle()
.findType(ImageResource.class.getCanonicalName());
}
public static String getName() {
return "resourceUrl";
}
@Override
public Integer getNumExpectedArguments() {
return 1;
}
@Override
public List<CssValueNode> getCallResultNodes(List<CssValueNode> cssValueNodes, ErrorManager errorManager)
throws GssFunctionException {
CssValueNode functionToEval = cssValueNodes.get(0);
String value = functionToEval.getValue();
SourceCodeLocation location = functionToEval.getSourceCodeLocation();
String javaExpression = buildJavaExpression(value, location, errorManager);
CssFunctionNode urlNode = buildUrlNode(javaExpression, location);
return ImmutableList.<CssValueNode>of(urlNode);
}
@Override
public String getCallResultString(List<String> strings) throws GssFunctionException {
return strings.get(0);
}
private String buildJavaExpression(String value, SourceCodeLocation location,
ErrorManager errorManager) throws GssFunctionException {
CssDotPathNode dotPathValue = new CssDotPathNode(value, "", "", location);
assertMethodIsValidResource(location, dotPathValue.getPathElements(), errorManager);
return context.getImplementationSimpleSourceName() + ".this."
+ dotPathValue.getValue() + ".getSafeUri().asString()";
}
private void assertMethodIsValidResource(SourceCodeLocation location, List<String> pathElements,
ErrorManager errorManager) throws GssFunctionException {
JType methodType;
try {
methodType = ResourceGeneratorUtil.getMethodByPath(context.getClientBundleType(),
pathElements, null).getReturnType();
} catch (NotFoundException e) {
String message = e.getMessage();
errorManager.report(new GssError(message, location));
throw new GssFunctionException(message, e);
}
if (!dataResourceType.isAssignableFrom((JClassType) methodType) &&
!imageResourceType.isAssignableFrom((JClassType) methodType)) {
String message = "Invalid method type for url substitution: " + methodType + ". " +
"Only DataResource and ImageResource are supported.";
errorManager.report(new GssError(message, location));
throw new GssFunctionException(message);
}
}
private CssFunctionNode buildUrlNode(String javaExpression, SourceCodeLocation location) {
CssFunctionNode urlNode = GssFunctions.createUrlNode("", location);
CssJavaExpressionNode cssJavaExpressionNode = new CssJavaExpressionNode(javaExpression);
CssFunctionArgumentsNode arguments =
new CssFunctionArgumentsNode(ImmutableList.<CssValueNode>of(cssJavaExpressionNode));
urlNode.setArguments(arguments);
return urlNode;
}
}