Code Snippet Ember Component

This is an Ember component (and ember-cli addon) that lets you render code snippets within your app. The code snippets can live in their own dedicated files or you can extract blocks of code from your application itself.

• Syntax highlighting thanks to highlight.js. To see how it looks, view the highlightjs previews.
• ember-cli's auto-reload will pick up changes to any of the snippet files.
• the component uses file extensions to help highlight.js guess the right language. See below for details on choosing the supported languages.

Install

ember install ember-code-snippet

Usage

There are two ways to store your code snippets. You can use either or both together.

With separate snippet files

Create a new "snippets" directory at the top level of your ember-cli application or addon, and place the code snippets you'd like to render in their own files inside it. They will be identified by filename. So if you create the file snippets/sample-template.hbs, you can embed it in a template with:

{{code-snippet name="sample-template.hbs"}}

You can choose to load snippet files from different paths by passing an option to new EmberApp in your ember-cli-build.js:

var app = new EmberApp({
  snippetPaths: ['snippets']
});

If you want to use snippets located in an addon's dummy application, add the dummy app path to snippetPaths:

var app = new EmberAddon({
  snippetPaths: ['tests/dummy/app']
});

From within your application source

In any file under your app tree, annotate the start and end of a code snippet block by placing comments like this:

// BEGIN-SNIPPET my-nice-example
function sample(){
  return 42;
};
// END-SNIPPET

The above is a Javascript example, but you can use any language's comment format. We're just looking for lines that match /\bBEGIN-SNIPPET\s+(\S+)\b/ and /\bEND-SNIPPET\b/.

The opening comment must include a name. The component will identify these snippets using the names you specified plus the file extension of the file in which they appeared (which helps us detect languages for better highlighting). So the above example could be included in a template like this:

{{code-snippet name="my-nice-example.js"}}

You can also define your own regex to find snippets. Just use the snippetRegexes option:

var app = new EmberAddon({
 snippetRegexes: {
   begin: /{{#element-example\sname=\"(\S+)\"/,
   end: /{{\/element-example}}/,
 }
});

In the regex above everything in the element-example component block will be a snippet! Just make sure the first regex capture group is the name of the snippet.

By default, the component will try to unindent the code block by removing whitespace characters from the start of each line until the code bumps up against the edge. You can disable this with:

{{code-snippet name="my-nice-example.js" unindent=false}}

You can choose which paths will be searched for inline snippets by settings the snippetSearchPaths option when creating your application in ember-cli-build.js:

var app = new EmberApp({
  snippetSearchPaths: ['app', 'other']
});

By default, the file extension from the containing file will automatically be included in the snippet name. For instance, the example above has BEGIN-SNIPPET my-nice-example in the JS source, and is subsequently referenced as "my-nice-example.js". To disable this behavior, use the includeFileExtensionInSnippetNames option:

var app = new EmberApp({
  includeFileExtensionInSnippetNames: false
});

Syntax Highlighting Language Support

We depend on highlight.js for syntax highlighting. It supports 176 languages. But you probably don't want to build all of those into your app.

Out of the box, we only enable:

• css
• coffeescript
• html/xml
• json
• javascript
• markdown
• handlebars
• htmlbars

If you want a different set, you can:

1. Tell ember-code-snippet not to include highlight.js automatically for you:

  // in ember-cli-build.js
  var app = new EmberApp(defaults, {
    includeHighlightJS: false
  });

2. Go to https://highlightjs.org/download/ and generate your own build of highlight.js using the languages you want.

3. Place the resulting highlight.pack.js in your vendor directory.

4. Import it directly from your ember-cli-build.js file:

app.import('vendor/highlight.pack.js', {
  using: [ { transformation: 'amd', as: 'highlight.js' } ]
});

Theming Support

We include a basic syntax-highlighting theme by default, but highlight.js has 79 different themes to choose from and it's possible to make your own just by writing a stylesheet.

To use a different theme:

1. Tell ember-code-snippet not to include its own theme:

  // in ember-cli-build.js
  var app = new EmberApp(defaults, {
    includeHighlightStyle: false
  });

2. Place your chosen style in vendor.

3. Import it directly from your ember-cli-build.js:

app.import('vendor/my-highlight-style.css');