/*
* Copyright 2000-2016 Vaadin Ltd.
*
* 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.vaadin.sass.linker;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import org.w3c.css.sac.CSSException;
import com.google.gwt.core.ext.LinkerContext;
import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.core.ext.UnableToCompleteException;
import com.google.gwt.core.ext.linker.AbstractLinker;
import com.google.gwt.core.ext.linker.ArtifactSet;
import com.google.gwt.core.ext.linker.EmittedArtifact;
import com.google.gwt.core.ext.linker.LinkerOrder;
import com.google.gwt.core.ext.linker.LinkerOrder.Order;
import com.google.gwt.core.ext.linker.Shardable;
import com.vaadin.sass.internal.ScssStylesheet;
/**
* Pre-linker that checks for the existence of SASS files in public folders,
* compiles them to CSS files with the SassCompiler from Vaadin and adds the CSS
* back into the artifact.
*
*/
@LinkerOrder(Order.PRE)
@Shardable
public class SassLinker extends AbstractLinker {
@Override
public String getDescription() {
return "Compiling SCSS files in public folders to standard CSS";
}
@Override
public ArtifactSet link(TreeLogger logger, LinkerContext context,
ArtifactSet artifacts, boolean onePermutation)
throws UnableToCompleteException {
if (!onePermutation) {
// The artifact to return
ArtifactSet toReturn = new ArtifactSet(artifacts);
// The temporary scss files provided from the artefacts
List<FileInfo> scssFiles = new ArrayList<>();
// The public files are provided as inputstream, but the compiler
// needs real files, as they can contain references to other
// files. They will be stored here, with their relative paths intact
String tempFolderName = new Date().getTime() + File.separator;
File tempFolder = createTempDir(tempFolderName);
// Can't search here specifically for public resources, as the type
// is different during compilation. This means we have to loop
// through all the artifacts
for (EmittedArtifact resource : artifacts
.find(EmittedArtifact.class)) {
// Create the temporary files.
String partialPath = resource.getPartialPath();
if (partialPath.endsWith(".scss")) {
// In my opinion, the SCSS file does not need to be
// output to the web content folder, as they can't
// be used there
toReturn.remove(resource);
String fileName = partialPath;
File path = tempFolder;
int separatorIndex = fileName.lastIndexOf(File.separator);
if (-1 != separatorIndex) {
fileName = fileName.substring(separatorIndex + 1);
String filePath = partialPath.substring(0,
separatorIndex);
path = createTempDir(tempFolderName + filePath);
}
File tempfile = new File(path, fileName);
try {
boolean fileCreated = tempfile.createNewFile();
if (fileCreated) {
// write the received inputstream to the temp file
writeFromInputStream(resource.getContents(logger),
tempfile);
// Store the file info for the compilation
scssFiles.add(new FileInfo(tempfile, partialPath));
} else {
logger.log(TreeLogger.WARN,
"Duplicate file " + tempfile.getPath());
}
} catch (IOException e) {
logger.log(TreeLogger.ERROR,
"Could not write temporary file " + fileName,
e);
}
}
}
// Compile the files and store them in the artifact
logger.log(TreeLogger.INFO,
"Processing " + scssFiles.size() + " Sass file(s)");
for (FileInfo fileInfo : scssFiles) {
logger.log(TreeLogger.INFO, " " + fileInfo.originalScssPath
+ " -> " + fileInfo.getOriginalCssPath());
try {
ScssStylesheet scss = ScssStylesheet
.get(fileInfo.getAbsolutePath());
if (!fileInfo.isMixin()) {
scss.compile();
InputStream is = new ByteArrayInputStream(
scss.printState().getBytes());
toReturn.add(this.emitInputStream(logger, is,
fileInfo.getOriginalCssPath()));
}
fileInfo.getFile().delete();
} catch (CSSException e) {
logger.log(TreeLogger.ERROR, "SCSS compilation failed for "
+ fileInfo.getOriginalCssPath(), e);
} catch (IOException e) {
logger.log(TreeLogger.ERROR, "Could not write CSS file for "
+ fileInfo.getOriginalCssPath(), e);
} catch (Exception e) {
logger.log(TreeLogger.ERROR, "SCSS compilation failed for "
+ fileInfo.getOriginalCssPath(), e);
}
}
return toReturn;
}
return artifacts;
}
/**
* Writes the contents of an InputStream out to a file.
*
* @param contents
* @param tempfile
* @throws IOException
*/
private void writeFromInputStream(InputStream contents, File tempfile)
throws IOException {
// write the inputStream to a FileOutputStream
OutputStream out = new FileOutputStream(tempfile);
int read = 0;
byte[] bytes = new byte[1024];
while ((read = contents.read(bytes)) != -1) {
out.write(bytes, 0, read);
}
contents.close();
out.flush();
out.close();
}
/**
* Create folder in temporary space on disk.
*
* @param partialPath
* @return
*/
private File createTempDir(String partialPath) {
String baseTempPath = System.getProperty("java.io.tmpdir");
File tempDir = new File(baseTempPath + File.separator + partialPath);
if (!tempDir.exists()) {
tempDir.mkdirs();
}
tempDir.deleteOnExit();
return tempDir;
}
/**
* Temporal storage for file info from Artifact.
*/
private class FileInfo {
private String originalScssPath;
private File file;
public FileInfo(File file, String originalScssPath) {
this.file = file;
this.originalScssPath = originalScssPath;
}
public boolean isMixin() {
return file.getName().startsWith("_");
}
public String getAbsolutePath() {
return file.getAbsolutePath();
}
public String getOriginalCssPath() {
return originalScssPath.substring(0, originalScssPath.length() - 5)
+ ".css";
}
public File getFile() {
return file;
}
}
}