grunt-contrib-watch

Run predefined tasks whenever watched file patterns are added, changed or deleted.

Note that this plugin has not yet been released, and only works with the latest bleeding-edge, in-development version of grunt. See the When will I be able to use in-development feature 'X'? FAQ entry for more information.

Getting Started

If you haven't used grunt before, be sure to check out the Getting Started guide.

From the same directory as your project's Gruntfile and package.json, install this plugin with the following command:

npm install grunt-contrib-watch --save-dev

Once that's done, add this line to your project's Gruntfile:

grunt.loadNpmTasks('grunt-contrib-watch');

If the plugin has been installed correctly, running grunt --help at the command line should list the newly-installed plugin's task or tasks. In addition, the plugin should be listed in package.json as a devDependency, which ensures that it will be installed whenever the npm install command is run.

The watch task

Overview

Inside your Gruntfile.js file, add a section named watch. This section specifies the files to watch, tasks to run when an event occurs and the options used.

Settings

There are a number of options available. Please review the minimatch options here. As well as some additional options as follows:

tasks

Type: String|Array

This defines which tasks to run when a watched file event occurs.

options.interrupt

Type: boolean Default: false

As files are modified this watch task will spawn tasks in child processes. The default behavior will only spawn a new child process per target when the previous process has finished. Set the interrupt option to true to terminate the previous process and spawn a new one upon later changes.

Example:

watch: {
  scripts: {
    files: '**/*.js',
    tasks: ['jshint'],
    options: {
      interrupt: true
    }
  }
}

options.debounceDelay

Type: Integer Default: 500

How long to wait before emitting events in succession for the same filepath and status. For example if your Gruntfile.js file was changed, a changed event will only fire again after the given milliseconds.

Example:

watch: {
  scripts: {
    files: '**/*.js',
    tasks: ['jshint'],
    options: {
      debounceDelay: 250
    }
  }
}

options.interval

Type: Integer Default: 100

The interval is passed to fs.watchFile. Since interval is only used by fs.watchFile and this watcher also uses fs.watch; it is recommended to ignore this option. Default is 100ms.

Examples

// Simple config to run jshint any time a file is added, changed or deleted
grunt.initConfig({
  watch: {
    files: '**/*',
    tasks: ['jshint']
  }
});

// Advanced config. Run specific tasks when specific files are added, changed or deleted.
grunt.initConfig({
  watch: {
    gruntfile: {
      files: 'Gruntfile.js',
      tasks: ['jshint:gruntfile'],
      options: {
        nocase: true
      }
    },
    src: {
      files: ['lib/*.js', 'css/**/*.scss', '!lib/dontwatch.js'],
      tasks: ['default']
    },
    test: {
      files: '<%= jshint.test.src %>',
      tasks: ['jshint:test', 'qunit']
    }
  }
});

Release History

• 2012-10-07 - v0.1.0 - Release watch task Remove spawn from helper Run on Grunt v0.4
• 2012-10-15 - v0.1.1 - Fallback to global grunt bin if local doesnt exist. Fatal if bin cannot be found Update to gaze 0.1.6
• 2012-10-16 - v0.1.2 - Only spawn a process per task one at a time Add interrupt option to cancel previous spawned process Grunt v0.3 compatibility changes

-- Task submitted by Kyle Robinson Young.

Generated on Thu Oct 18 2012 17:23:15.