mincer/lib/mincer/engines/coffee_engine.js

Web assets processor. Native JavaScript port of Sprockets.

/**
 *  class CoffeeEngine
 *
 *  Engine for the CoffeeScript compiler. You will need `coffee-script` Node
 *  module installed in order to use [[Mincer]] with `*.coffee` and
 *  `*.litcoffee` files:
 *
 *      npm install coffee-script
 *
 *
 *  ##### SUBCLASS OF
 *
 *  [[Template]]
 **/


'use strict';


// stdlib
var extname = require('path').extname;


// 3rd-party
var _ = require('lodash');
var path = require('path');
var coffee; // initialized later


// internal
var Template  = require('../template');
var prop      = require('../common').prop;


////////////////////////////////////////////////////////////////////////////////


// Class constructor
var CoffeeEngine = module.exports = function CoffeeEngine() {
  Template.apply(this, arguments);
  coffee = coffee || Template.libs.coffee || require('coffee-script');
};


require('util').inherits(CoffeeEngine, Template);


// Internal (private) options storage
var options = { bare: true };


/**
 *  CoffeeEngine.configure(opts) -> Void
 *  - opts (Object):
 *
 *  Allows to set CoffeeScript compilation options.
 *  Default: `{bare: true}`.
 *
 *  ##### Example
 *
 *      CoffeeScript.configure({bare: true});
 **/
CoffeeEngine.configure = function (opts) {
  options = _.clone(opts);
};


// Render data
CoffeeEngine.prototype.evaluate = function (context/*, locals*/) {
  var loc, compileOpts, result;

  compileOpts = _.assign({}, options, {
    literate: extname(this.file) === '.litcoffee'
  });

  try {
    // coffescript result change structure, depending on
    // soursemaps option.
    if (context.environment.isEnabled('source_maps')) {
      compileOpts = _.assign(compileOpts, {
        inline:      true,
        sourceMap:   true,
        sourceFiles: [ path.basename(context.pathname) ]
      });

      result = coffee.compile(this.data, compileOpts);
      this.data = result.js;
      this.map = result.v3SourceMap;

    } else {
      this.data = coffee.compile(this.data, compileOpts);
    }

  } catch (err) {
    loc = err.location;

    if (loc) {
      loc = 'L' + (loc.first_line + 1) + ':' + (loc.first_column + 1);
      err.message += ' at ' + loc;
    }

    throw err;
  }
};


// Expose default MimeType of an engine
prop(CoffeeEngine, 'defaultMimeType', 'application/javascript');