grunt-image-embed/README.md

Grunt task for embedding images as base64 data URIs inside your stylesheets.

# Grunt Image Embed

This task converts all data found within a stylesheet (those within a url( ... ) declaration) into base64-encoded data URI strings. This includes images and fonts.

Created by Eric Hynds [@erichynds](http://twitter.com/erichynds) with major contributions from [dancingplatypus](https://github.com/dancingplatypus).

## Features

* Supports both local & remote images.
* Ability to specify a size limit. Default is 32kb which is IE8's limit.
* Existing data URIs will be ignored.
* Skip specific images by specifying a directive comment.
* Ability to purge images that have been encoded
* Includes two helpers: `encode_stylesheet` to encode a stylesheet, and `encode_image` to encode an image.

## Getting Started

Install this plugin with the command:

```js
npm install grunt-image-embed
```

Next, add this line to your project's grunt file:

```js
grunt.loadNpmTasks("grunt-image-embed");
```

Lastly, add configuration settings to your grunt.js file (see below).

## Documentation

This task has two required properties, `src` and `dest`. `src` is the path to your stylesheet and `dest` is the file this task will write to (relative to the grunt.js file). If this file already exists **it will be overwritten**.

An example configuration looks like this:

```js
grunt.initConfig({
  imageEmbed: {
    dist: {
      src: [ "css/styles.css" ],
      dest: "css/output.css",
      options: {
        deleteAfterEncoding : false,
        preEncodeCallback: function (filename) { return true; }
      }
    }
  }
});
```

### Optional Configuration Properties

ImageEmbed can be customized by specifying the following options:

* `maxImageSize`: The maximum size of the base64 string in bytes. This defaults to `32768`, or IE8's limit. Set this to `0` to remove the limit and allow any size string.

* `baseDir`: If you have absolute image paths in your stylesheet, the path specified in this option will be used as the base directory.

* `deleteAfterEncoding`: Set this to true to delete images after they've been encoded. You'll want to do this in a staging area, and not in your source directories.  Be careful.

* `preEncodeCallback`: function that takes full path to the image to be encoded and returns either `true` (proceeed with default encoding), `false` (abort the encoding, fail with error) or String, which will be used as the result of the encoding.

* `regexInclude` - Regular expression testing against file types to include. Defaults to all (`/.*/g`). To only include images, you might set this to `/\.(jpg|png|gif|jpeg)/gi`.

* `regexExclude` - Regular expression testing against file types to exclude. Defaults to none (``/$^/g`). To exclude fonts for example, you might set this to `/\.(eot|woff|ttf|svg)/gi`.

### Skipping Images

Specify that an image should be skipped by adding the following comment directive *after* the image:

```css
background: url(image.gif); /*ImageEmbed:skip*/
```

## Compatibility

Version >= 0.3.0 of this plugin is compatible with Grunt 0.4.x. Versions 0.0.1 through 0.2.0 are only compatible with Grunt 0.3.x.

## License

Copyright (c) 2013 Eric Hynds (@erichynds)
Licensed under the MIT License.