SassLinker for (public folder) Sass support in plain GWT, fixes #10202

Originally by Michael Vogt (+ added log message, moved)

Change-Id: I565207b4fa5223f470e1e5bbdc196d4c343a8142

1 files changed, 195 insertions, 0 deletions

diff --git a/client-compiler/src/com/vaadin/sass/linker/SassLinker.java b/client-compiler/src/com/vaadin/sass/linker/SassLinker.java
new file mode 100644
index 0000000000..82a228a166
--- /dev/null
+++ b/client-compiler/src/com/vaadin/sass/linker/SassLinker.java
@@ -0,0 +1,195 @@
+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 SASS 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 sass files provided from the artefacts
+            List<FileInfo> sassFiles = new ArrayList<FileInfo>();
+
+            // 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);
+
+            // Create the temporary files
+            for (EmittedArtifact resource : artifacts
+                    .find(EmittedArtifact.class)) {
+
+                String partialPath = resource.getPartialPath();
+                if (partialPath.endsWith(".scss")) {
+
+                    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
+                            sassFiles.add(new FileInfo(tempfile, partialPath));
+
+                            // In my oppinion, the SASS file does not need to be
+                            // output to the web content, as they can't be used
+                            // there
+                            toReturn.remove(resource);
+                        }
+                    } catch (IOException e) {
+                        // TODO Auto-generated catch block
+                        e.printStackTrace();
+                    }
+                }
+            }
+
+            // Compile the files and store them in the artifact
+            logger.log(TreeLogger.INFO, "Processing " + sassFiles.size()
+                    + " Sass file(s)");
+            for (FileInfo fileInfo : sassFiles) {
+                logger.log(TreeLogger.INFO, "   " + fileInfo.originalScssPath
+                        + " -> " + fileInfo.getOriginalCssPath());
+
+                ScssStylesheet scss;
+
+                try {
+                    scss = ScssStylesheet.get(fileInfo.getAbsolutePath());
+                    scss.compile();
+                    InputStream is = new ByteArrayInputStream(scss.toString()
+                            .getBytes());
+
+                    toReturn.add(this.emitInputStream(logger, is,
+                            fileInfo.getOriginalCssPath()));
+                } catch (CSSException e) {
+                    // TODO Auto-generated catch block
+                    e.printStackTrace();
+                } catch (IOException e) {
+                    // TODO Auto-generated catch block
+                    e.printStackTrace();
+                } catch (Exception e) {
+                    // TODO Auto-generated catch block
+                    e.printStackTrace();
+                }
+            }
+
+            return toReturn;
+        }
+
+        return artifacts;
+    }
+
+    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.mkdir();
+        }
+
+        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 String getAbsolutePath() {
+            return file.getAbsolutePath();
+        }
+
+        public String getOriginalCssPath() {
+            return originalScssPath.substring(0, originalScssPath.length() - 5)
+                    + ".css";
+        }
+    }
+
+}