main.js

define(function (require, exports, module) {
  'use strict';

  // Get our Brackets modules
  var _ = brackets.getModule('thirdparty/lodash');
  var Commands = brackets.getModule('command/Commands');
  var CommandManager = brackets.getModule('command/CommandManager');
  var FileSystem = brackets.getModule('filesystem/FileSystem');
  var FileSystemImpl = FileSystem._FileSystem;
  var ProjectManager = brackets.getModule('project/ProjectManager');
  var PreferencesManager = brackets.getModule('preferences/PreferencesManager');
  var PackageJson = JSON.parse(require('text!./package.json'));
  var StateManager = PreferencesManager.stateManager;

  // Default excludes
  var defaultExcludeList = [
    '/.git/',
    '/dist/',
    '/bower_components/',
    '/node_modules/'
  ];

  // Get the preferences for this extension
  var preferences = PreferencesManager.getExtensionPrefs(PackageJson.name);
  preferences.definePreference('excludeList', 'array', defaultExcludeList);

  // projectRoot & projectPath
  var excludeList = null;
  var projectPath = null;

  // Check if the extension has been updated
  if (PackageJson.version !== StateManager.get(PackageJson.name + '.version')) {
    StateManager.set(PackageJson.name + '.version', PackageJson.version);
    preferences.set('excludeList', defaultExcludeList);
  }

  function escapeStringToRegexp(str) {
    // https://github.com/sindresorhus/escape-string-regexp/blob/master/index.js
    return str.replace(/[|\\{}()[\]^$+*?.]/g, '\\$&');
  }

  function toRegexp(str) {
    if (typeof str !== 'string') { str = str.toString(); }
    var start = '';
    var body = str;
    var end = '';
    // if starts with ^, it must be start of the string
    // if starts with /, it can be either start of the string or start of the file/folder
    if (body[0] === '^') {
      start = '^';
      body = body.slice(1);
    } else if (body[0] === '/') {
      start = '(^|/)';
      body = body.slice(1);
    }
    // if ends with slash, make it possible end of the string too
    if (body.slice(-1) === '/') {
      end = '(/|$)';
      body = body.slice(0, -1);
    }
    return start + escapeStringToRegexp(body) + end;
  }

  function fetchVariables(forceRefresh) {
    var projectRoot = ProjectManager.getProjectRoot();
    projectPath = projectRoot ? projectRoot.fullPath : null;
    excludeList = preferences.get('excludeList', projectPath);
    excludeList = excludeList.map(toRegexp);

    if (forceRefresh === true) {
      CommandManager.execute(Commands.FILE_REFRESH);
    }
  }

  function clearVariables() {
    projectPath = null;
  }

  // attach events
  ProjectManager.on('projectOpen', function () { fetchVariables(true); });
  ProjectManager.on('projectRefresh', function () { fetchVariables(true); });
  ProjectManager.on('beforeProjectClose', function () { clearVariables(); });
  FileSystem.on('change', function (event, entry, added, removed) {
    // entry === null when manual refresh is done
    if (entry == null) {
      fetchVariables(false);
    } else if (entry.name === '.brackets.json') {
      fetchVariables(true);
    }
  });

  // Filter itself
  var _oldFilter = FileSystemImpl.prototype._indexFilter;
  FileSystemImpl.prototype._indexFilter = function (path, name) {

    if (!excludeList || !projectPath) {
      fetchVariables();
      if (!excludeList || !projectPath) {
        return _oldFilter.apply(this, arguments);
      }
    }

    var relativePath = path.slice(projectPath.length);

    var excluded = _.any(excludeList, function (toMatch) {
      return relativePath.match(toMatch) != null;
    });

    return excluded ? false : _oldFilter.apply(this, arguments);
  };

});