angucomplete-alt.js

/*
 * angucomplete-alt
 * Autocomplete directive for AngularJS
 * This is a fork of Daryl Rowland's angucomplete with some extra features.
 * By Hidenari Nozaki
 */

/*! Copyright (c) 2014 Hidenari Nozaki and contributors | Licensed under the MIT license */

(function (root, factory) {
  'use strict';
  if (typeof module !== 'undefined' && module.exports) {
    // CommonJS
    module.exports = factory(require('angular'));
  } else if (typeof define === 'function' && define.amd) {
    // AMD
    define(['angular'], factory);
  } else {
    // Global Variables
    factory(root.angular);
  }
}(window, function (angular) {
  'use strict';

  angular.module('angucomplete-alt', []).directive('angucompleteAlt', ['$q', '$parse', '$http', '$sce', '$timeout', '$templateCache', '$interpolate', '$sanitize', function ($q, $parse, $http, $sce, $timeout, $templateCache, $interpolate, $sanitize) {
    // keyboard events
    var KEY_DW  = 40;
    var KEY_RT  = 39;
    var KEY_UP  = 38;
    var KEY_LF  = 37;
    var KEY_ES  = 27;
    var KEY_EN  = 13;
    var KEY_TAB =  9;

    var MIN_LENGTH = 3;
    var MAX_LENGTH = 524288;  // the default max length per the html maxlength attribute
    var PAUSE = 500;
    var BLUR_TIMEOUT = 200;

    // string constants
    var REQUIRED_CLASS = 'autocomplete-required';
    var TEXT_SEARCHING = 'Searching...';
    var TEXT_NORESULTS = 'No results found';
    var TEMPLATE_URL = '/angucomplete-alt/index.html';

    // Set the default template for this directive
    $templateCache.put(TEMPLATE_URL,
        '<div class="angucomplete-holder" ng-class="{\'angucomplete-dropdown-visible\': showDropdown}">' +
        '  <input id="{{id}}_value" name="{{inputName}}" tabindex="{{fieldTabindex}}" ng-class="{\'angucomplete-input-not-empty\': notEmpty}" ng-model="searchStr" ng-disabled="disableInput" type="{{inputType}}" placeholder="{{placeholder}}" maxlength="{{maxlength}}" ng-focus="onFocusHandler()" class="{{inputClass}}" ng-focus="resetHideResults()" ng-blur="hideResults($event)" autocapitalize="off" autocorrect="off" autocomplete="off" ng-change="inputChangeHandler(searchStr)"/>' +
        '  <div id="{{id}}_dropdown" class="angucomplete-dropdown" ng-show="showDropdown">' +
        '    <div class="angucomplete-searching" ng-show="searching" ng-bind="textSearching"></div>' +
        '    <div class="angucomplete-searching" ng-show="!searching && (!results || results.length == 0)" ng-bind="textNoResults"></div>' +
        '    <div class="angucomplete-row" ng-repeat="result in results" ng-click="selectResult(result)" ng-mouseenter="hoverRow($index)" ng-class="{\'angucomplete-selected-row\': $index == currentIndex}">' +
        '      <div ng-if="imageField" class="angucomplete-image-holder">' +
        '        <img ng-if="result.image && result.image != \'\'" ng-src="{{result.image}}" class="angucomplete-image"/>' +
        '        <div ng-if="!result.image && result.image != \'\'" class="angucomplete-image-default"></div>' +
        '      </div>' +
        '      <div class="angucomplete-title" ng-if="matchClass" ng-bind-html="result.title"></div>' +
        '      <div class="angucomplete-title" ng-if="!matchClass">{{ result.title }}</div>' +
        '      <div ng-if="matchClass && result.description && result.description != \'\'" class="angucomplete-description" ng-bind-html="result.description"></div>' +
        '      <div ng-if="!matchClass && result.description && result.description != \'\'" class="angucomplete-description">{{result.description}}</div>' +
        '    </div>' +
        '  </div>' +
        '</div>'
    );

    function link(scope, elem, attrs, ctrl) {
      var inputField = elem.find('input');
      var minlength = MIN_LENGTH;
      var searchTimer = null;
      var hideTimer;
      var requiredClassName = REQUIRED_CLASS;
      var responseFormatter;
      var validState = null;
      var httpCanceller = null;
      var dd = elem[0].querySelector('.angucomplete-dropdown');
      var isScrollOn = false;
      var mousedownOn = null;
      var unbindInitialValue;
      var displaySearching;
      var displayNoResults;

      elem.on('mousedown', function(event) {
        if (event.target.id) {
          mousedownOn = event.target.id;
          if (mousedownOn === scope.id + '_dropdown') {
            document.body.addEventListener('click', clickoutHandlerForDropdown);
          }
        }
        else {
          mousedownOn = event.target.className;
        }
      });

      scope.currentIndex = scope.focusFirst ? 0 : null;
      scope.searching = false;
      unbindInitialValue = scope.$watch('initialValue', function(newval) {
        if (newval) {
          // remove scope listener
          unbindInitialValue();
          // change input
          handleInputChange(newval, true);
        }
      });

      scope.$watch('fieldRequired', function(newval, oldval) {
        if (newval !== oldval) {
          if (!newval) {
            ctrl[scope.inputName].$setValidity(requiredClassName, true);
          }
          else if (!validState || scope.currentIndex === -1) {
            handleRequired(false);
          }
          else {
            handleRequired(true);
          }
        }
      });

      scope.$on('angucomplete-alt:clearInput', function (event, elementId) {
        if (!elementId || elementId === scope.id) {
          scope.searchStr = null;
          callOrAssign();
          handleRequired(false);
          clearResults();
        }
      });

      scope.$on('angucomplete-alt:changeInput', function (event, elementId, newval) {
        if (!!elementId && elementId === scope.id) {
          handleInputChange(newval);
        }
      });

      function handleInputChange(newval, initial) {
        if (newval) {
          if (typeof newval === 'object') {
            scope.searchStr = extractTitle(newval);
            callOrAssign({originalObject: newval});
          } else if (typeof newval === 'string' && newval.length > 0) {
            scope.searchStr = newval;
          } else {
            if (console && console.error) {
              console.error('Tried to set ' + (!!initial ? 'initial' : '') + ' value of angucomplete to', newval, 'which is an invalid value');
            }
          }

          handleRequired(true);
        }
      }

      // #194 dropdown list not consistent in collapsing (bug).
      function clickoutHandlerForDropdown(event) {
        mousedownOn = null;
        scope.hideResults(event);
        document.body.removeEventListener('click', clickoutHandlerForDropdown);
      }

      // for IE8 quirkiness about event.which
      function ie8EventNormalizer(event) {
        return event.which ? event.which : event.keyCode;
      }

      function callOrAssign(value) {
        if (typeof scope.selectedObject === 'function') {
          scope.selectedObject(value, scope.selectedObjectData);
        }
        else {
          scope.selectedObject = value;
        }

        if (value) {
          handleRequired(true);
        }
        else {
          handleRequired(false);
        }
      }

      function callFunctionOrIdentity(fn) {
        return function(data) {
          return scope[fn] ? scope[fn](data) : data;
        };
      }

      function setInputString(str) {
        callOrAssign({originalObject: str});

        if (scope.clearSelected) {
          scope.searchStr = null;
        }
        clearResults();
      }

      function extractTitle(data) {
        // split title fields and run extractValue for each and join with ' '
        return scope.titleField.split(',')
          .map(function(field) {
            return extractValue(data, field);
          })
          .join(' ');
      }

      function extractValue(obj, key) {
        var keys, result;
        if (key) {
          keys= key.split('.');
          result = obj;
          for (var i = 0; i < keys.length; i++) {
            result = result[keys[i]];
          }
        }
        else {
          result = obj;
        }
        return result;
      }

      function findMatchString(target, str) {

        var result, matches, re;

        if (!target) { return; }
        if (!target.match || !target.replace) { target = target.toString(); }

        target = $sanitize(target);

        if (scope.matchAllTokens) {

          // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions
          // Escape user input to be treated as a literal string within a regular expression
          // Splits the user input by space and puts it on an array: ex -> 'software is an amazing thing' = ['software', 'is', 'an', 'amazing', 'thing']
          // Joins the array above by | to be an "OR" for each term of the array on the regex.
          // Final regex would be: '/(software|is|an|amazing|thing)/gi'
          re = new RegExp('('+str.replace(/[.*+?^${}()|[\]\\]/g, '\\$&').match(/\S+/g).join('|')+')', 'gi');

          matches = target.match(re);

          if (matches) {
            result = target.replace(re, '<span class="'+ scope.matchClass +'">$1</span>');
          }

        }
        else{

          // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions
          // Escape user input to be treated as a literal string within a regular expression
          re = new RegExp(str.replace(/[.*+?^${}()|[\]\\]/g, '\\$&'), 'i');

          matches = target.match(re);

          if (matches) {
            result = target.replace(re,
                '<span class="'+ scope.matchClass +'">'+ matches[0] +'</span>');
          }
        }

        if (!matches) {
          result = target;
        }

        return $sce.trustAsHtml(result);
      }

      function handleRequired(valid) {
        scope.notEmpty = valid;
        validState = scope.searchStr;
        if (scope.fieldRequired && ctrl && scope.inputName) {
          ctrl[scope.inputName].$setValidity(requiredClassName, valid);
        }
      }

      function keyupHandler(event) {
        var which = ie8EventNormalizer(event);
        if (which === KEY_LF || which === KEY_RT) {
          // do nothing
          return;
        }

        if (which === KEY_UP || which === KEY_EN) {
          event.preventDefault();
        }
        else if (which === KEY_DW) {
          event.preventDefault();
          if (!scope.showDropdown && scope.searchStr && scope.searchStr.length >= minlength) {
            initResults();
            scope.searching = true;
            searchTimerComplete(scope.searchStr);
          }
        }
        else if (which === KEY_ES) {
          clearResults();
          scope.$apply(function() {
            inputField.val(scope.searchStr);
          });
        }
        else {
          if (minlength === 0 && !scope.searchStr) {
            return;
          }

          if (!scope.searchStr || scope.searchStr === '') {
            scope.showDropdown = false;
          } else if (scope.searchStr.length >= minlength) {
            initResults();

            if (searchTimer) {
              $timeout.cancel(searchTimer);
            }

            scope.searching = true;

            searchTimer = $timeout(function() {
              searchTimerComplete(scope.searchStr);
            }, scope.pause);
          }

          if (validState && validState !== scope.searchStr && !scope.clearSelected) {
            scope.$apply(function() {
              callOrAssign();
            });
          }
        }
      }

      function handleOverrideSuggestions(event) {
        if (scope.overrideSuggestions &&
            !(scope.selectedObject && scope.selectedObject.originalObject === scope.searchStr)) {
          if (event) {
            var which = ie8EventNormalizer(event);
            if (which !== KEY_EN || (which === KEY_EN && !scope.enterSubmitsForm)) {
              event.preventDefault();
            }
          }

          // cancel search timer
          $timeout.cancel(searchTimer);
          // cancel http request
          cancelHttpRequest();

          setInputString(scope.searchStr);
        }
      }

      function dropdownRowOffsetHeight(row) {
        var css = getComputedStyle(row);
        return row.offsetHeight +
          parseInt(css.marginTop, 10) + parseInt(css.marginBottom, 10);
      }

      function dropdownHeight() {
        return dd.getBoundingClientRect().top +
          parseInt(getComputedStyle(dd).maxHeight, 10);
      }

      function dropdownRow() {
        return elem[0].querySelectorAll('.angucomplete-row')[scope.currentIndex];
      }

      function dropdownRowTop() {
        return dropdownRow().getBoundingClientRect().top -
          (dd.getBoundingClientRect().top +
           parseInt(getComputedStyle(dd).paddingTop, 10));
      }

      function dropdownScrollTopTo(offset) {
        dd.scrollTop = dd.scrollTop + offset;
      }

      function updateInputField(){
        var current = scope.results[scope.currentIndex];
        if (scope.matchClass) {
          inputField.val(extractTitle(current.originalObject));
        }
        else {
          inputField.val(current.title);
        }
      }

      function keydownHandler(event) {
        var which = ie8EventNormalizer(event);
        var row = null;
        var rowTop = null;

        if (which === KEY_EN && scope.results) {
          if (scope.currentIndex >= 0 && scope.currentIndex < scope.results.length) {
            if (!scope.enterSubmitsForm) {
              event.preventDefault();
            }
            scope.selectResult(scope.results[scope.currentIndex]);
          } else if (scope.searchStr !== '') {
            handleOverrideSuggestions(event);
            clearResults();
            if (!scope.enterSubmitsForm) {
              event.currentTarget.blur();
            }
          }
          scope.$apply();
        } else if (which === KEY_DW && scope.results) {
          event.preventDefault();
          if ((scope.currentIndex + 1) < scope.results.length && scope.showDropdown) {
            scope.$apply(function() {
              scope.currentIndex ++;
              updateInputField();
            });

            if (isScrollOn) {
              row = dropdownRow();
              if (dropdownHeight() < row.getBoundingClientRect().bottom) {
                dropdownScrollTopTo(dropdownRowOffsetHeight(row));
              }
            }
          }
        } else if (which === KEY_UP && scope.results) {
          event.preventDefault();
          if (scope.currentIndex >= 1) {
            scope.$apply(function() {
              scope.currentIndex --;
              updateInputField();
            });

            if (isScrollOn) {
              rowTop = dropdownRowTop();
              if (rowTop < 0) {
                dropdownScrollTopTo(rowTop - 1);
              }
            }
          }
          else if (scope.currentIndex === 0) {
            scope.$apply(function() {
              scope.currentIndex = -1;
              inputField.val(scope.searchStr);
            });
          }
        } else if (which === KEY_TAB) {
          if (scope.results && scope.results.length > 0 && scope.showDropdown) {
            if (scope.currentIndex === -1 && scope.overrideSuggestions) {
              // intentionally not sending event so that it does not
              // prevent default tab behavior
              handleOverrideSuggestions();
            }
            else {
              if (scope.currentIndex === -1) {
                scope.currentIndex = 0;
              }
              scope.selectResult(scope.results[scope.currentIndex]);
              scope.$digest();
            }
          }
          else {
            // no results
            // intentionally not sending event so that it does not
            // prevent default tab behavior
            if (scope.searchStr && scope.searchStr.length > 0) {
              handleOverrideSuggestions();
            }
          }
        } else if (which === KEY_ES) {
          // This is very specific to IE10/11 #272
          // without this, IE clears the input text
          event.preventDefault();
        }
      }

      function httpSuccessCallbackGen(str) {
        return function(responseData, status, headers, config) {
          // normalize return obejct from promise
          if (!status && !headers && !config && responseData.data) {
            responseData = responseData.data;
          }
          scope.searching = false;
          processResults(
            extractValue(responseFormatter(responseData), scope.remoteUrlDataField),
            str);
        };
      }

      function httpErrorCallback(errorRes, status, headers, config) {
        scope.searching = false;

        // cancelled/aborted
        if (status === 0 || status === -1) { return; }

        // normalize return obejct from promise
        if (!status && !headers && !config) {
          status = errorRes.status;
        }
        if (scope.remoteUrlErrorCallback) {
          scope.remoteUrlErrorCallback(errorRes, status, headers, config);
        }
        else {
          if (console && console.error) {
            console.error('http error');
          }
        }
      }

      function cancelHttpRequest() {
        if (httpCanceller) {
          httpCanceller.resolve();
        }
      }

      function getRemoteResults(str) {
        var params = {},
            url = scope.remoteUrl + encodeURIComponent(str);
        if (scope.remoteUrlRequestFormatter) {
          params = {params: scope.remoteUrlRequestFormatter(str)};
          url = scope.remoteUrl;
        }
        if (!!scope.remoteUrlRequestWithCredentials) {
          params.withCredentials = true;
        }
        cancelHttpRequest();
        httpCanceller = $q.defer();
        params.timeout = httpCanceller.promise;
        $http.get(url, params)
          .success(httpSuccessCallbackGen(str))
          .error(httpErrorCallback);
      }

      function getRemoteResultsWithCustomHandler(str) {
        cancelHttpRequest();

        httpCanceller = $q.defer();

        scope.remoteApiHandler(str, httpCanceller.promise)
          .then(httpSuccessCallbackGen(str))
          .catch(httpErrorCallback);

        /* IE8 compatible
        scope.remoteApiHandler(str, httpCanceller.promise)
          ['then'](httpSuccessCallbackGen(str))
          ['catch'](httpErrorCallback);
        */
      }

      function clearResults() {
        scope.showDropdown = false;
        scope.results = [];
        if (dd) {
          dd.scrollTop = 0;
        }
      }

      function initResults() {
        scope.showDropdown = displaySearching;
        scope.currentIndex = scope.focusFirst ? 0 : -1;
        scope.results = [];
      }

      function getLocalResults(str) {
        var i, match, s, value,
            searchFields = scope.searchFields.split(','),
            matches = [];
        if (typeof scope.parseInput() !== 'undefined') {
          str = scope.parseInput()(str);
        }
        for (i = 0; i < scope.localData.length; i++) {
          match = false;

          for (s = 0; s < searchFields.length; s++) {
            value = extractValue(scope.localData[i], searchFields[s]) || '';
            match = match || (value.toString().toLowerCase().indexOf(str.toString().toLowerCase()) >= 0);
          }

          if (match) {
            matches[matches.length] = scope.localData[i];
          }
        }
        return matches;
      }

      function checkExactMatch(result, obj, str){
        if (!str) { return false; }
        for(var key in obj){
          if(obj[key].toLowerCase() === str.toLowerCase()){
            scope.selectResult(result);
            return true;
          }
        }
        return false;
      }

      function searchTimerComplete(str) {
        // Begin the search
        if (!str || str.length < minlength) {
          return;
        }
        if (scope.localData) {
          scope.$apply(function() {
            var matches;
            if (typeof scope.localSearch() !== 'undefined') {
              matches = scope.localSearch()(str, scope.localData);
            } else {
              matches = getLocalResults(str);
            }
            scope.searching = false;
            processResults(matches, str);
          });
        }
        else if (scope.remoteApiHandler) {
          getRemoteResultsWithCustomHandler(str);
        } else {
          getRemoteResults(str);
        }
      }

      function processResults(responseData, str) {
        var i, description, image, text, formattedText, formattedDesc;

        if (responseData && responseData.length > 0) {
          scope.results = [];

          for (i = 0; i < responseData.length; i++) {
            if (scope.titleField && scope.titleField !== '') {
              text = formattedText = extractTitle(responseData[i]);
            }

            description = '';
            if (scope.descriptionField) {
              description = formattedDesc = extractValue(responseData[i], scope.descriptionField);
            }

            image = '';
            if (scope.imageField) {
              image = extractValue(responseData[i], scope.imageField);
            }

            if (scope.matchClass) {
              formattedText = findMatchString(text, str);
              formattedDesc = findMatchString(description, str);
            }

            scope.results[scope.results.length] = {
              title: formattedText,
              description: formattedDesc,
              image: image,
              originalObject: responseData[i]
            };
          }

        } else {
          scope.results = [];
        }

        if (scope.autoMatch && scope.results.length === 1 &&
            checkExactMatch(scope.results[0],
              {title: text, desc: description || ''}, scope.searchStr)) {
          scope.showDropdown = false;
        } else if (scope.results.length === 0 && !displayNoResults) {
          scope.showDropdown = false;
        } else {
          scope.showDropdown = true;
        }
      }

      function showAll() {
        if (scope.localData) {
          processResults(scope.localData, '');
        }
        else if (scope.remoteApiHandler) {
          getRemoteResultsWithCustomHandler('');
        }
        else {
          getRemoteResults('');
        }
      }

      scope.onFocusHandler = function() {
        if (scope.focusIn) {
          scope.focusIn();
        }
        if (minlength === 0 && (!scope.searchStr || scope.searchStr.length === 0)) {
          scope.currentIndex = scope.focusFirst ? 0 : scope.currentIndex;
          scope.showDropdown = true;
          showAll();
        }
      };

      scope.hideResults = function() {
        if (mousedownOn &&
            (mousedownOn === scope.id + '_dropdown' ||
             mousedownOn.indexOf('angucomplete') >= 0)) {
          mousedownOn = null;
        }
        else {
          hideTimer = $timeout(function() {
            clearResults();
            scope.$apply(function() {
              if (scope.searchStr && scope.searchStr.length > 0) {
                inputField.val(scope.searchStr);
              }
            });
          }, BLUR_TIMEOUT);
          cancelHttpRequest();

          if (scope.focusOut) {
            scope.focusOut();
          }

          if (scope.overrideSuggestions) {
            if (scope.searchStr && scope.searchStr.length > 0 && scope.currentIndex === -1) {
              handleOverrideSuggestions();
            }
          }
        }
      };

      scope.resetHideResults = function() {
        if (hideTimer) {
          $timeout.cancel(hideTimer);
        }
      };

      scope.hoverRow = function(index) {
        scope.currentIndex = index;
      };

      scope.selectResult = function(result) {
        // Restore original values
        if (scope.matchClass) {
          result.title = extractTitle(result.originalObject);
          result.description = extractValue(result.originalObject, scope.descriptionField);
        }

        if (scope.clearSelected) {
          scope.searchStr = null;
        }
        else {
          scope.searchStr = result.title;
        }
        callOrAssign(result);
        clearResults();
      };

      scope.inputChangeHandler = function(str) {
        if (str.length < minlength) {
          cancelHttpRequest();
          clearResults();
        }
        else if (str.length === 0 && minlength === 0) {
          scope.searching = false;
          showAll();
        }

        if (scope.inputChanged) {
          str = scope.inputChanged(str);
        }
        return str;
      };

      // check required
      if (scope.fieldRequiredClass && scope.fieldRequiredClass !== '') {
        requiredClassName = scope.fieldRequiredClass;
      }

      // check min length
      if (scope.minlength && scope.minlength !== '') {
        minlength = parseInt(scope.minlength, 10);
      }

      // check pause time
      if (!scope.pause) {
        scope.pause = PAUSE;
      }

      // check clearSelected
      if (!scope.clearSelected) {
        scope.clearSelected = false;
      }

      // check override suggestions
      if (!scope.overrideSuggestions) {
        scope.overrideSuggestions = false;
      }

      // check required field
      if (scope.fieldRequired && ctrl) {
        // check initial value, if given, set validitity to true
        if (scope.initialValue) {
          handleRequired(true);
        }
        else {
          handleRequired(false);
        }
      }

      scope.inputType = attrs.type ? attrs.type : 'text';

      // set strings for "Searching..." and "No results"
      scope.textSearching = attrs.textSearching ? attrs.textSearching : TEXT_SEARCHING;
      scope.textNoResults = attrs.textNoResults ? attrs.textNoResults : TEXT_NORESULTS;
      displaySearching = scope.textSearching === 'false' ? false : true;
      displayNoResults = scope.textNoResults === 'false' ? false : true;

      // set max length (default to maxlength deault from html
      scope.maxlength = attrs.maxlength ? attrs.maxlength : MAX_LENGTH;

      // register events
      inputField.on('keydown', keydownHandler);
      inputField.on('keyup', keyupHandler);

      // set response formatter
      responseFormatter = callFunctionOrIdentity('remoteUrlResponseFormatter');

      // set isScrollOn
      $timeout(function() {
        var css = getComputedStyle(dd);
        isScrollOn = css.maxHeight && css.overflowY === 'auto';
      });
    }

    return {
      restrict: 'EA',
      require: '^?form',
      scope: {
        selectedObject: '=',
        selectedObjectData: '=',
        disableInput: '=',
        initialValue: '=',
        localData: '=',
        localSearch: '&',
        remoteUrlRequestFormatter: '=',
        remoteUrlRequestWithCredentials: '@',
        remoteUrlResponseFormatter: '=',
        remoteUrlErrorCallback: '=',
        remoteApiHandler: '=',
        id: '@',
        type: '@',
        placeholder: '@',
        textSearching: '@',
        textNoResults: '@',
        remoteUrl: '@',
        remoteUrlDataField: '@',
        titleField: '@',
        descriptionField: '@',
        imageField: '@',
        inputClass: '@',
        pause: '@',
        searchFields: '@',
        minlength: '@',
        matchClass: '@',
        matchAllTokens: '@',
        clearSelected: '@',
        overrideSuggestions: '@',
        fieldRequired: '=',
        fieldRequiredClass: '@',
        inputChanged: '=',
        enterSubmitsForm: '@',
        autoMatch: '@',
        focusOut: '&',
        focusIn: '&',
        fieldTabindex: '@',
        inputName: '@',
        focusFirst: '@',
        parseInput: '&'
      },
      templateUrl: function(element, attrs) {
        return attrs.templateUrl || TEMPLATE_URL;
      },
      compile: function(tElement) {
        var startSym = $interpolate.startSymbol();
        var endSym = $interpolate.endSymbol();
        if (!(startSym === '{{' && endSym === '}}')) {
          var interpolatedHtml = tElement.html()
            .replace(/\{\{/g, startSym)
            .replace(/\}\}/g, endSym);
          tElement.html(interpolatedHtml);
        }
        return link;
      }
    };
  }]);

}));