Source: ml-remote-input.service.js

(function() {
  'use strict';

  angular.module('ml.search')
    .service('MLRemoteInputService', MLRemoteInputService);

  MLRemoteInputService.$inject = ['$injector'];

  /**
   * @class MLRemoteInputService
   * @classdesc angular service for working with {@link ml-remote-input}
   *
   * @param {Object} $injector - angular dependency resolution service
   */
  function MLRemoteInputService($injector) {
    var service = this,
        $route = null;

    this.routeAvailable = true;

    try {
      $route = $injector.get('$route');
    } catch (ex) {
      this.routeAvailable = false;
    }

    service.input = '';
    service.mlSearch = null;
    service.callbacks = [];

    function unsubscribe(idx) {
      service.callbacks.splice(idx);
    }

    /**
     * sets the service.input instance property and invokes the registered callbacks
     * @method MLRemoteInputService#setInput
     *
     * @param {string} input
     */
    service.setInput = function setInput(input) {
      service.input = input;
      // TODO: Object.observe service.input?
      _.each(service.callbacks, function(callback) {
        callback(service.input);
      });
    };

    /**
     * registers a callback, returning a de-registration function
     * @method MLRemoteInputService#subscribe
     *
     * @param {function} callback - a callback to be invoked when `this.input` is changed
     * @return {function} callback de-registration function
     */
    service.subscribe = function subscribe(callback) {
      var idx = service.callbacks.length;
      service.callbacks.push(callback);
      return function() {
        unsubscribe(idx);
      };
    };

    /**
     * helper function for mlRemoteInput directive
     * registers and de-registers a callback that
     *   - updates the $scope parameter
     *   - updates the mlSearch parameter with the mlSearch instance property
     *     (if it exists)
     * @method MLRemoteInputService#initInput
     *
     * @param {object} $scope - search controller scope
     * @param {MLSearchContext} mlSearch - controller mlSearch instance
     */
    service.initInput = function initInput($scope, mlSearch) {
      var unsubscribe = service.subscribe(function(input) {
        $scope.qtext = input;
        mlSearch = service.mlSearch || mlSearch;
      });

      $scope.$on('destroy', unsubscribe);
    };

    /**
     * helper function for Search controller
     *
     * - registers and de-registers a callback that
     *   - updates the qtext property of the model parameter
     *   - invokes the searchCallback
     * - sets the mlSearch instance property
     * - initializes the qtext property of the model parameter
     *   (unless it's already set and the instance input property is not)
     *
     * @method MLRemoteInputService#initCtrl
     * @deprecated
     *
     * @param {object} $scope - search controller scope
     * @param {object} model - search controller model
     * @param {MLSearchContext} mlSearch - controller mlSearch instance
     * @param {function} searchCallback - search callback function
     */
    service.initCtrl = function initCtrl($scope, model, mlSearch, searchCallback) {
      var unsubscribe = service.subscribe(function(input) {
        if (model.qtext !== input) {
          model.qtext = input;

          searchCallback();
        }
      });

      $scope.$on('$destroy', unsubscribe);

      service.mlSearch = mlSearch;

      if ( model.qtext.length && !service.input.length ) {
        service.setInput( model.qtext );
      } else {
        model.qtext = service.input;
      }
    };

    /**
     * gets the path for a specified controller from the `$route` service (if available)
     * @method MLRemoteInputService#getPath
     *
     * @param {string} searchCtrl - search controller name
     * @return {?string} search controller path
     */
    service.getPath = function getPath(searchCtrl) {
      var route = { originalPath: '/' },
          matches = null;

      if ($route === null) {
        return null;
      }

      matches = _.where($route.routes, { controller: searchCtrl });

      if ( matches.length === 0 ) {
        // TODO: get route from attr, or throw Error('can\t find Search controller') ?
        console.error('can\'t find Search controller: ' + searchCtrl);
      } else {
        route = matches[0];

        if ( matches.length > 1 ) {
          console.log('multiple Search controller routes; choosing \'' +
                      route.originalPath + '\'');
        }
      }

      return route.originalPath;
    };
  }
}());