Expand snippets matching the current prefix with tab in Atom.

To add your own snippets, select the Atom > Open Your Snippets menu option if you're using OSX or the File > Open Your Snippets menu option if you're using Windows or Linux.

Snippets files are stored in a package's snippets/ folder and also loaded from ~/.atom/snippets.cson.

Snippet files can be either .json or .cson.

'.source.js':
  'console.log':
    'prefix': 'log'
    'body': 'console.log(${1:"crash"});$2'

The outermost keys are the selectors where this snippets should be active (details below).

The next level of keys are the snippet names.

Under each snippet name is a prefix that should trigger the snippet and a body to insert when the snippet is triggered.

$ followed by a number are the tabs stops which can be cycled between by pressing tab once a snippet has been triggered.

The above example adds a log snippet to JavaScript files that would expand to.

console.log("crash");

The string "crash" would be initially selected and pressing tab again would place the cursor after the ;

The outmost key of a snippet is the "scope" that you want the descendent snippets to be available in. You can find out the correct scope by opening the Settings (cmd+, on OS X) and selecting the corresponding Language [xxx] package, e.g. for Language Html:

If it's difficult to determine the package handling the file type in question (for example, for .md-documents), you can also proceed as following. Put your cursor in a file in which you want the snippet to be available, open the Command Palette (cmd+shift+p), and run the Editor: Log Cursor Scope command. This will trigger a notification which will contain a list of scopes. The first scope that's listed is the scope for that language. Here are some examples: source.coffee, text.plain, text.html.basic.

You can also use multi-line syntax using """ for larger templates:

'.source.js':
  'if, else if, else':
    'prefix': 'ieie'
    'body': """
      if (${1:true}) {
        $2
      } else if (${3:false}) {
        $4
      } else {
        $5
      }
    """

Including a literal closing brace inside the text provided by a snippet's tab stop will close that tab stop early. To prevent that, escape the brace with two backslashes, like so:

'.source.js':
  'function':
    'prefix': 'funct'
    'body': """
      ${1:function () {
        statements;
      \\}
      this line is also included in the snippet tab;
      }
      """

Snippets for the same scope must be placed within the same key. See this section of the Atom Flight Manual for more information.