# gulp-inject [![NPM version][npm-image]][npm-url] [![Build Status][travis-image]][travis-url] [![Dependency Status][depstat-image]][depstat-url]

> A stylesheet, javascript and webcomponent reference injection plugin for [gulp](https://github.com/wearefractal/gulp). No more manual editing of your index.html!

`gulp-inject` takes a stream of source files, transforms each file to a string and injects each transformed string into placeholders in the target stream files. See [Basic usage](#basic-usage) and [More examples](#more-examples) below.

Default [transforms](#optionstransform) and [placeholders](#optionsstarttag) exists for injecting files into `html`, `jade` and `jsx` files.

## Installation

Install `gulp-inject` as a development dependency:

```shell
npm install --save-dev gulp-inject
```

## Basic usage

**The target file `src/index.html`:**

Each pair of comments are the injection placeholders (aka. tags, see [`options.starttag`](#optionsstarttag) and [`options.endtag`](#optionsendtag)).

```html
<!DOCTYPE html>
<html>
<head>
  <title>My index</title>
  <!-- inject:css -->
  <!-- endinject -->
</head>
<body>

  <!-- inject:js -->
  <!-- endinject -->
</body>
</html>
```

**The `gulpfile.js`:**

```javascript
var gulp = require('gulp');
var inject = require("gulp-inject");

gulp.task('index', function () {
  var target = gulp.src('./src/index.html');
  // It's not necessary to read the files (will speed up things), we're only after their paths:
  var sources = gulp.src(['./src/**/*.js', './src/**/*.css'], {read: false});

  return target.pipe(inject(sources))
    .pipe(gulp.dest('./src'));
});
```

**`src/index.html` after running `gulp index`:**

```html
<!DOCTYPE html>
<html>
<head>
  <title>My index</title>
  <!-- inject:css -->
  <link rel="stylesheet" href="/src/style1.css">
  <link rel="stylesheet" href="/src/style2.css">
  <!-- endinject -->
</head>
<body>

  <!-- inject:js -->
  <script src="/src/lib1.js"></script>
  <script src="/src/lib2.js"></script>
  <!-- endinject -->
</body>
</html>
```

## More examples

### Injecting files relative to target files

By default the injected file paths are relative to each source file's `cwd` (see [`options.ignorePath`](#optionsignorepath)). If `options.relative` is set to `true` each injected path will be relative to each target file's directory instead.

**Project structure:**

```
└── src
    ├── module
    │   ├── module.js
    │   └── module.html
    └── app
        ├── main.js
        └── index.html
```

**`src/app/index.html`:**

```html
<!DOCTYPE html>
<html>
<head>
  <title>My Index</title>
</head>
<body>
  <h1>Home</h1>
  <!-- inject:js -->
  <!-- endinject -->
</body>
</html>
```

**`src/module/module.html`:**

```html
<!DOCTYPE html>
<html>
<head>
  <title>Module</title>
</head>
<body>
  <h1>Module</h1>
  <!-- inject:js -->
  <!-- endinject -->
</body>
</html>
```

**`gulpfile.js`:**

```javascript
var inject = require('gulp-inject');

gulp.src('./src/**/*.html')
  .pipe(inject(gulp.src('./src/**/*.js', {read: false}), {relative: true}))
  .pipe('./src');
```

**Resulting `src/app/index.html`:**

```html
<!DOCTYPE html>
<html>
<head>
  <title>My Index</title>
</head>
<body>
  <h1>Home</h1>
  <!-- inject:js -->
  <script src="main.js"></script>
  <script src="../module/module.js"></script>
  <!-- endinject -->
</body>
</html>
```

**Resulting `src/module/module.html`:**

```html
<!DOCTYPE html>
<html>
<head>
  <title>Module</title>
</head>
<body>
  <h1>Home</h1>
  <!-- inject:js -->
  <script src="../app/main.js"></script>
  <script src="module.js"></script>
  <!-- endinject -->
</body>
</html>
```

### Injecting files from multiple source streams

This example demonstrates how to inject files from multiple different streams into the same injection placeholder.

Install [`event-stream`](https://www.npmjs.org/package/event-stream) with: `npm install --save-dev event-stream` and use its [`merge`](https://github.com/dominictarr/event-stream#merge-stream1streamn) function.

**Code:**

```javascript
var es = require('event-stream'),
    inject = require('gulp-inject');

// Concatenate vendor scripts
var vendorStream = gulp.src(['./src/vendors/*.js'])
  .pipe(concat('vendors.js'))
  .pipe(gulp.dest('./dist'));

// Concatenate AND minify app sources
var appStream = gulp.src(['./src/app/*.js'])
  .pipe(concat('app.js'))
  .pipe(uglify())
  .pipe(gulp.dest('./dist'));

gulp.src('./src/index.html')
  .pipe(inject(es.merge(vendorStream, appStream)))
  .pipe(gulp.dest('./dist'));
```

### Injecting some files into `<head>` and some into `<body>`

#### Method 1: Use `gulp-inject`'s `starttag` option.

**`gulpfile.js`:**

```javascript
var inject = require('gulp-inject');

gulp.src('./src/index.html')
  .pipe(inject(gulp.src('./src/importantFile.js', {read: false}), {starttag: '<!-- inject:head:{{ext}} -->'}))
  .pipe(inject(gulp.src(['./src/*.js', '!./src/importantFile.js'], {read: false})))
  .pipe(gulp.dest('./dist'));
```

**And in your `./src/index.html`:**

```html
<!DOCTYPE html>
<html>
<head>
  <title>My index</title>
  <!-- inject:head:js -->
  <!-- only importantFile.js will be injected here -->
  <!-- endinject -->
</head>
<body>

  <!-- inject:js -->
  <!-- the rest of the *.js files will be injected here -->
  <!-- endinject -->
</body>
</html>
```

#### Method 2: Use `gulp-inject`'s `name` option.

**`gulpfile.js`:**

```javascript
var inject = require('gulp-inject');

gulp.src('./src/index.html')
  .pipe(inject(gulp.src('./src/importantFile.js', {read: false}), {name: 'head'}))
  .pipe(inject(gulp.src(['./src/*.js', '!./src/importantFile.js'], {read: false})))
  .pipe(gulp.dest('./dist'));
```

**And in your `./src/index.html`:**

```html
<!DOCTYPE html>
<html>
<head>
  <title>My index</title>
  <!-- head:js -->
  <!-- only importantFile.js will be injected here -->
  <!-- endinject -->
</head>
<body>

  <!-- inject:js -->
  <!-- the rest of the *.js files will be injected here -->
  <!-- endinject -->
</body>
</html>
```


### Injecting all files for development

If you use [Bower](http://bower.io/) for frontend dependencies I recommend using [`main-bower-files`](https://www.npmjs.org/package/main-bower-files) and injecting them as well.

**`gulpfile.js`:**

```javascript
var bowerFiles = require('main-bower-files'),
    inject = require('gulp-inject'),
    stylus = require('gulp-stylus'),
    es = require('event-stream');

var cssFiles = gulp.src('./src/**/*.styl')
  .pipe(stylus())
  .pipe(gulp.dest('./build'));

gulp.src('./src/index.html')
  .pipe(inject(gulp.src(bowerFiles(), {read: false}), {name: 'bower'}))
  .pipe(inject(es.merge(
    cssFiles,
    gulp.src('./src/app/**/*.js', {read: false})
  )))
  .pipe(gulp.dest('./build'));
```

**`src/index.html`:**

```html
<!DOCTYPE html>
<html>
<head>
  <title>My index</title>
  <!-- bower:css -->
  <!-- bower installed css files will go here... -->
  <!-- endinject -->
  <!-- inject:css -->
  <!-- built css files will go here... -->
  <!-- endinject -->
</head>
<body>

  <!-- bower:js -->
  <!-- bower installed scripts will go here... -->
  <!-- endinject -->
  <!-- inject:js -->
  <!-- app scripts will go here... -->
  <!-- endinject -->
</body>
</html>
```

**Note** remember to mount `./bower_components`, `./build` and `./src/app` as static resources in your server to make this work.

### Injecting AngularJS scripts for development

If you're writing an AngularJS application and follow [Google's Angular APP Structure Recommendations](https://docs.google.com/document/d/1XXMvReO8-Awi1EZXAXS4PzDzdNvV6pGcuaF4Q9821Es/pub), which I think you should, it's important that the script files are injected in the correct order to avoid module instantiation problems like `Uncaught Error: [$injector:modulerr]`.

To do this you can use [`gulp-angular-filesort`](https://www.npmjs.org/package/gulp-angular-filesort) together with `gulp-inject` like so:

```javascript
var angularFilesort = require('gulp-angular-filesort'),
    inject = require('gulp-inject');

gulp.src('./src/index.html')
  .pipe(inject(
    gulp.src('./src/app/**/*.js') // gulp-angular-filesort depends on file contents, so don't use {read: false} here
      .pipe(angularFilesort())
    }
  )))
  .pipe(gulp.dest('./build'));
```

### Injecting into a json-file

You can customize `gulp-inject` further by using the `transform` function option, e.g. by injecting files into a json-file.

**Code:**

```javascript
gulp.src('./files.json')
  .pipe(inject(gulp.src(['./src/*.js', './src/*.css', './src/*.html'], {read: false}), {
    starttag: '"{{ext}}": [',
    endtag: ']',
    transform: function (filepath, file, i, length) {
      return '  "' + filepath + '"' + (i + 1 < length ? ',' : '');
    }
  }))
  .pipe(gulp.dest('./'));
```

Initial contents of `files.json`:

```json
{
  "js": [
  ],
  "css": [
  ],
  "html": [
  ]
}
```

### Injecting with custom `transform` function with default fallback

The [default `transform`](#injecttransform) function is available to use e.g. as a default fallback.

Used here to inject Word documents as `<a>` tags below:

**`index.html`:**

```html
<!DOCTYPE html>
<html>
<head>
  <title>My documents</title>
</head>
<body>
  <h1>Documents</h1>
  <ul>
    <!-- inject:docx -->
    <!-- endinject -->
  </ul>
  <!-- inject:js -->
  <!-- endinject -->
</body>
</html>
```

**`gulpfile.js`:**

```javascript
var inject = require('gulp-inject');

gulp.src('./index.html')
  .pipe(inject(
    gulp.src(['./*.js', './docs/*.docx'], {read: false}), {
      transform: function (filepath) {
        if (filepath.slice(-5) === '.docx') {
          return '<li><a href="' + filepath + '">' + filepath + '</a></li>';
        }
        // Use the default transform as fallback:
        return inject.transform.apply(inject.transform, arguments);
      }
    }
  ))
  .pipe(gulp.dest('./'));
```

**Resulting `index.html`:**

```html
<!DOCTYPE html>
<html>
<head>
  <title>My documents</title>
</head>
<body>
  <h1>Documents</h1>
  <ul>
    <!-- inject:docx -->
    <li><a href="/docs/document1.docx"></a></li>
    <li><a href="/docs/document2.docx"></a></li>
    <!-- endinject -->
  </ul>
  <!-- inject:js -->
  <script src="/lib1.js"></script>
  <script src="/lib2.js"></script>
  <!-- endinject -->
</body>
</html>
```

### Injecting dist files into bower.json's main section

**Code:**

```javascript
gulp.src('./bower.json')
  .pipe(inject(gulp.src(['./dist/app.min.js', './dist/app.min.css'], {read: false}), {
    starttag: '"main": [',
    endtag: ']',
    transform: function (filepath, file, i, length) {
      return '  "' + filepath + '"' + (i + 1 < length ? ',' : '');
    }
  }))
  .pipe(gulp.dest('./'));
```

### Injecting all javascript files into a karma config file

**Code:**

```javascript
gulp.src('./karma.conf.js')
  .pipe(inject(gulp.src(['./src/**/*.js'], {read: false}), {
    starttag: 'files: [',
    endtag: ']',
    transform: function (filepath, file, i, length) {
      return '  "' + filepath + '"' + (i + 1 < length ? ',' : '');
    }
  }))
  .pipe(gulp.dest('./'));
```

### Injecting files contents

In order to inject files contents you have to provide custom `transform` function, that will return file contents as string. You also have to omit `{read: false}` option of `gulp.src` in this case. Example below shows how to inject contents of html partials into head of `index.html`:

***Code:***

```javascript
gulp.src('./src/index.html')
  .pipe(inject(gulp.src(['./src/partials/head/*.html']), {
    starttag: '<!-- inject:head:{{ext}} -->',
    transform: function (filePath, file) {
      // return file contents as string
      return file.contents.toString('utf8')
    }
  }))
  .pipe(gulp.dest('./dest'));
```

And in your `./src/index.html`:

```html
<!DOCTYPE html>
<html>
<head>
  <title>My index</title>
  <!-- inject:head:html -->
  <!-- contents of html partials will be injected here -->
  <!-- endinject -->
</head>
<body>
</body>
</html>
```

## API

### inject(sources, options)

#### sources
Type: `Stream`

Provide a Vinyl File Stream as input to `inject`, see examples above.

**N.B:** The old behavior, where you specify target as a string is deprecated since `v.1.0`.

#### options.ignorePath
Type: `String` or `Array`

Default: `NULL`


A path or paths that should be removed from each injected file path.

This could also be solved by setting the `cwd` option for your `gulp.src` streams, each source file's `cwd` is automatically removed from its path before injection (if not [`options.relative`](#optionsrelative) is set to `true`, see below).


#### options.relative
Type: `Boolean`

Default: `false`


If set to `true` paths for the injected files will be relative to each target file, this also means that each source file's `cwd` is not necessary to remove from its path.


#### options.addPrefix
Type: `String`

Default: `NULL`


A path that should be prefixed to each injected file path.

#### options.addRootSlash
Type: `Boolean`

Default: `![options.relative](#optionsrelative)`


The root slash is automatically added at the beginning of the path ('/'), or removed if set to `false`.

#### options.name
Type: `String`

Default: `"inject"`


Used in the default [start](#optionsstarttag) and [end](#optionsendtag) tags below.


#### options.starttag

**Type:** `String`|`Function(targetExt, sourceExt)`

**Params (if function):**
  - `targetExt` - The file extension of the target file
  - `sourceExt` - The file extension of source file

**Purpose:**

Used to dynamically set starting placeholder tag depending on file extensions.
In the provided string, or the string returned from the given function, the string `{{ext}}` is replaced with the source file extension name, e.g. "css", "js" or "html". `{{name}}` will be replaced by [`option.name`](#optionname).

##### Default:

A function dependent on target file type and source file type that returns:

* html as target: `<!-- {{name}}:{{ext}} -->`
* jade as target: `//- {{name}}:{{ext}}`
* jsx as target: `{/* {{name}}:{{ext}} */}`

#### options.endtag

**Type:** `String`|`Function(targetExt, sourceExt)`

**Params (if function):**
  - `targetExt` - The file extension of the target file
  - `sourceExt` - The file extension of source file

**Purpose:**

Used to dynamically set ending placeholder tag depending on file extensions.
In the provided string, or the string returned from the given function, the string `{{ext}}` is replaced with the source file extension name, e.g. "css", "js" or "html". `{{name}}` will be replaced by [`option.name`](#optionname).

##### Default:

A function dependent on target file type and source file type that returns:

* html as target: `<!-- endinject -->`
* jade as target: `//- endinject`
* jsx as target: `{/* endinject */}`

#### options.transform

**Type**: `Function(filepath, file, index, length, targetFile)`

**Params:**
  - `filepath` - The "unixified" path to the file with any `ignorePath`'s removed and `addPrefix` added
  - `file` - The [File object](https://github.com/wearefractal/vinyl) to inject given from `gulp.src`
  - `index` - 0-based file index
  - `length` - Total number of files to inject for the current file extension
  - `targetFile` - The target [file](https://github.com/wearefractal/vinyl) to inject into

**Purpose:**

Used to generate the content to inject for each file.

##### Default:

[A function](#injecttransform) dependent on target file type and source file type that returns:

**Injecting into `html`**

* css files: `<link rel="stylesheet" href="<filename>.css">`
* js files: `<script src="<filename>.js"></script>`
* coffee files: `<script type="text/coffeescript" src="<filename>.coffee"></script>`
* html files: `<link rel="import" href="<filename>.html">`
* png files: `<img src="<filename>.png">`
* gif files: `<img src="<filename>.gif">`
* jpg files: `<img src="<filename>.jpg">`
* jpeg files: `<img src="<filename>.jpeg">`

If `options.selfClosingTag` is `true` the default transformer above will make the `<link>` and `<img>` tags self close, i.e: `<link ... />` and `<img ... />` respectively.

**Injecting into `jsx`**

The same as for injecting into `html` above with [`options.selfClosingTag`](#optionsselfclosingtag) set to `true`.

**Injecting into `jade`**

* css files: `link(rel="stylesheet", href="<filename>.css")`
* js files: `script(src="<filename>.js")`
* coffee files: `script(type="text/coffeescript", src="<filename>.coffee")`
* html files: `link(rel="import", href="<filename>.html")`
* png files: `img(src="<filename>.png")`
* gif files: `img(src="<filename>.gif")`
* jpg files: `img(src="<filename>.jpg")`
* jpeg files: `img(src="<filename>.jpeg")`

#### options.selfClosingTag
Type: `Boolean`

Default: `false`

Affects the default `options.transform` function, see above.


#### ~~options.templateString~~

***DEPRECATED!***

*Deprecated since `v.1.0`. Use [`gulp-file`](https://www.npmjs.org/package/gulp-file) instead:*

```javascript
var gulp = require('gulp');
var file = require('gulp-file');
var inject = require('gulp-inject');

file('index.html', '<html><head></head></html>')
  .pipe(inject(gulp.src(['./src/app/**/*.js']), {
    starttag: '<head>',
    endtag: '</head>'
  }))
  .pipe(gulp.dest('./dest'));
```

#### ~~options.sort~~

***DEPRECATED!***

*Deprecated since `v.1.0`. Use [`sort-stream`](https://www.npmjs.org/package/sort-stream) instead:*

```javascript
var gulp = require('gulp');
var sort = require('sort-stream');
var inject = require('gulp-inject');

gulp.src('index.html')
  .pipe(inject(gulp.src(['./src/app/**/*.js'])))
  .pipe(sort(function (a, b) {
    // Sort condition here...
  }))
  .pipe(gulp.dest('./dest'));
```

### inject.transform

The default transform function is exposed in the public API.

For more details see [the code with tests](https://github.com/klei/gulp-inject/tree/master/src/transform).

#### inject.transform.html

The default transform function for files into `html`, or other file types not `jade` or `jsx`.

#### inject.transform.jade

The default transform function for files into `jade`.

#### inject.transform.jsx

The default transform function for files into `jsx`.


## License

[MIT License](http://en.wikipedia.org/wiki/MIT_License)

[npm-url]: https://npmjs.org/package/gulp-inject
[npm-image]: https://badge.fury.io/js/gulp-inject.svg

[travis-url]: http://travis-ci.org/klei/gulp-inject
[travis-image]: https://secure.travis-ci.org/klei/gulp-inject.svg?branch=master

[depstat-url]: https://david-dm.org/klei/gulp-inject
[depstat-image]: https://david-dm.org/klei/gulp-inject.svg
