build-scripts/style-builder.js

   1 'use strict';
   2
   3 var gulp = require('gulp');
   4 var sourcemaps = require('gulp-sourcemaps');
   5 var less = require('gulp-less');
   6 var Promise = require('bluebird');
   7 var _ = require('lodash');
   8
   9 var lessWatcher = require('./less-watcher');
  10
  11 var defaults = {
  12   dest: './',
  13   sourceMapOptions: {},
  14   // ... postcss
  15   streamTransform: function(stream) {
  16     return stream;
  17   }
  18   // Also see `LessWatcher` opts, `watchGlob`, `lessOptions`
  19 };
  20
  21 module.exports = function(entryPoints, options) {
  22   var opts = _.extend({}, defaults, options);
  23
  24   var myLessWatcher = lessWatcher(entryPoints, opts);
  25
  26   var buildStyles = function(entryPoints) {
  27     return new Promise(function(resolve, reject) {
  28       // We use gulp here for easy building
  29       var stream = gulp
  30         .src(entryPoints)
  31         .pipe(sourcemaps.init())
  32         .pipe(less(opts.lessOptions));
  33
  34       opts
  35         .streamTransform(stream)
  36         .pipe(sourcemaps.write(opts.sourceMapOptions.dest, opts.sourceMapOptions.options))
  37         .pipe(gulp.dest(opts.dest))
  38         .on('end', function() {
  39           resolve();
  40         })
  41         .on('error', function(err) {
  42           reject(err);
  43         });
  44     });
  45   };
  46
  47   myLessWatcher.affectedEmitter.on('change', function(result) {
  48     console.log('affected', result);
  49     buildStyles(result).then(function() {
  50       console.log('building done');
  51     });
  52   });
  53
  54   return {
  55     build: function(force) {
  56       var getTargetEntryPointsPromise = Promise.resolve(entryPoints);
  57       if (!force) {
  58         getTargetEntryPointsPromise = myLessWatcher.getDirtyEntryPoints();
  59       }
  60
  61       return getTargetEntryPointsPromise
  62         .then(function(targetEntryPoints) {
  63           return buildStyles(targetEntryPoints);
  64         })
  65         .then(function() {
  66           console.log('building done');
  67         });
  68     },
  69     startWatching: myLessWatcher.startWatching.bind(myLessWatcher),
  70     stopWatching: myLessWatcher.stopWatching.bind(myLessWatcher)
  71   };
  72 };