Grunt-gm NPM | npm.io

grunt-gm v0.4.3

Batch process your images with gm.

Getting Started

This plugin requires Grunt ~0.4.0

If you haven't used Grunt before, be sure to check out the Getting Started guide, as it explains how to create a Gruntfile as well as install and use Grunt plugins. Once you're familiar with that process, you may install this plugin with this command:

npm install grunt-gm --save-dev

Once the plugin has been installed, it may be enabled inside your Gruntfile with this line of JavaScript:

grunt.loadNpmTasks('grunt-gm');

Overview

At the moment the task is pretty much just a simple grunt wrapper to gm.

Before start, please verify your GraphicsMagick or ImageMagick installation by running convert -vsersion.

If the task ran into error Fatal error: Maximum call stack size exceeded, it's probably because the files array is too long. To resolve this, try:

Run grunt with custom stack size node --stack-size=9999 node_modules/grunt-cli/bin/grunt gm
Check default by node --v8-options | grep -B0 -A1 stack_size

If your are on OSX, and the task ended with:

dyld: Library not loaded: /usr/local/lib/libfreetype.6.dylib
  Referenced from: /usr/local/bin/gm
  Reason: image not found

try brew unlink freetype && brew link freetype

The Task

See basic usages.

grunt.initConfig({
  gm: {
    test: {
      options: {
        // default: false, check if dest file exists and size > 0
        skipExisting: false,
        // default: false
        stopOnError: false,
        // task options will also be passed to arg callback
        yourcustomopt: {
          'test/gruntjs.png': '"JavaScript Task Runner"',
          'test/nodejs.png': '"JavaScript Runtime"'
        }
      },
      files: [
        {
          cwd: 'test',
          dest: 'test/out',
          expand: true,
          filter: 'isFile',
          src: ['**/*', '!**/out/*', '!{film,sample}.png'],
          options: {
            skipExisting: true,
            stopOnError: true
          }
          // image is passed as stream beteen tasks
          tasks: [
            {
              // resize and watermark
              resize: [200],
              command: ['composite'],
              in: ['test/sample.png']
            }, {
              // extent and center the image with padding arund it
              gravity: ['Center'],
              extent: [400, 360]
            }, {
              // frame it
              command: ['composite'],
              in: ['test/film.png']
            }, {
              // watermark text
              gravity: ['North'],
              font: ['arial', 30],
              draw: [
                'skewX', -13,
                // function in arg list will be called with current file object
                'fill', '#999', 'text', 2, 67, function (f) {return f.options.yourcustomopt[f.src[0]]},
                'fill', '#000', 'text', 0, 65, function (f) {return f.options.yourcustomopt[f.src[0]]}
              ]
            }
          ]
        }
      ]
    }
  }
});

Original	After Task #1	After Task #2	After Task #3	After Task #4

Options precedence:
1. CLI, eg. --skipExising
- File, eg. files:[{options:{skipExising:true}}]
- Task, eg. gm:{task1:{options:{skipExising:true}}
Task will traverse the file list and execute gm tasks one by one, top down
Grunt with --verbose flag to print out corresponding gm argument list