Ant Task for Invoking LessCSS (Updated)

>Update (August 26, 2009): I’ve polished the Ant task for LessCSS files quite a bit and implemented support for both lessc and plessc (the LessPHP alternative).

Features:

• converts .less files to .css
• supports both lessc and plessc (at least one is required)
• supports time-outs
• only processes changed files
• supports separate source/target directories, with include/exclude patterns

It’s available under de BSD-license for download from github: http://github.com/znerd/lesscss-ant-task/.

Notes:

• for lessc (tested lessc v1.1.13) to work to fail properly when lesscs fails, a minor change to one of the lessc files is required, this may be resolved in an upcoming version of the task and/or an upcoming version of lessc
• plessc v0.1.6 works well with the task, but has a rather annoying bug related to negative background positions.

Below is the original blog post.

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Here’s some sample code for implementating an Apache Ant task for invoking lesscss:

import java.io.File;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.DirectoryScanner;
import org.apache.tools.ant.taskdefs.Execute;
import org.apache.tools.ant.taskdefs.MatchingTask;

public final class LesscssTask extends MatchingTask {
 public LesscssTask() {
    setIncludes("*.less");
 }

 private File _sourceDir;
 private File _destDir;

 public void setDir(File dir) {
    _sourceDir = dir;
 }

 public void setToDir(File dir) {
    _destDir = dir;
 }

 @Override
 protected void execute() throws BuildException {
    for (String inFileName : getDirectoryScanner(_sourceDir).getIncludedFiles()) {
       File        inFile = new File(_sourceDir, inFileName);
       String outFileName = inFile.getName().replaceFirst("\\.less$", ".css");
       String outFilePath = new File(_destDir, outFileName).getPath();
       String  inFilePath = inFile.getPath();

       log("lesscss: From \"" + inFilePath + "\" to \"" + outFilePath + "\".");

       Execute.runCommand(this, new String[] { "lessc", inFilePath, outFilePath });
    }
 }
}

After defining the lesscss task in your build file (using a taskdef) invoking it is as simple as:

<lesscss dir="src/htdocs" todir="build/htdocs" />