text: function parseStateRef(ref, current) {
    var preparsed = ref.match(/^\s*({[^}]*})\s*$/), parsed;
    if (preparsed) ref = current + '(' + preparsed[1] + ')';
    parsed = ref.replace(/\n/g, " ").match(/^([^(]+?)\s*(\((.*)\))?$/);
    if (!parsed || parsed.length !== 4) throw new Error("Invalid state ref '" + ref + "'");
    return { state: parsed[1], paramExpr: parsed[3] || null };
  }
  
  function stateContext(el) {
    var stateData = el.parent().inheritedData('$uiView');
  
    if (stateData && stateData.state && stateData.state.name) {
      return stateData.state;
    }
  }
  
  function getTypeInfo(el) {
    // SVGAElement does not use the href attribute, but rather the 'xlinkHref' attribute.
    var isSvg = Object.prototype.toString.call(el.prop('href')) === '[object SVGAnimatedString]';
    var isForm = el[0].nodeName === "FORM";
  
    return {
      attr: isForm ? "action" : (isSvg ? 'xlink:href' : 'href'),
      isAnchor: el.prop("tagName").toUpperCase() === "A",
      clickable: !isForm
    };
  }
  
  function clickHook(el, $state, $timeout, type, current) {
    return function(e) {
      var button = e.which || e.button, target = current();
  
      if (!(button > 1 || e.ctrlKey || e.metaKey || e.shiftKey || el.attr('target'))) {
        // HACK: This is to allow ng-clicks to be processed before the transition is initiated:
        var transition = $timeout(function() {
          $state.go(target.state, target.params, target.options);
        });
        e.preventDefault();
  
        // if the state has no URL, ignore one preventDefault from the <a> directive.
        var ignorePreventDefaultCount = type.isAnchor && !target.href ? 1: 0;
  
        e.preventDefault = function() {
          if (ignorePreventDefaultCount-- <= 0) $timeout.cancel(transition);
        };
      }
    };
  }
  
  function defaultOpts(el, $state) {
    return { relative: stateContext(el) || $state.$current, inherit: true };
  }
  
  /**
   * @ngdoc directive
   * @name ui.router.state.directive:ui-sref
   *
   * @requires ui.router.state.$state
   * @requires $timeout
   *
   * @restrict A
   *
   * @description
   * A directive that binds a link (`<a>` tag) to a state. If the state has an associated
   * URL, the directive will automatically generate & update the `href` attribute via
   * the {@link ui.router.state.$state#methods_href $state.href()} method. Clicking
   * the link will trigger a state transition with optional parameters.
   *
   * Also middle-clicking, right-clicking, and ctrl-clicking on the link will be
   * handled natively by the browser.
   *
   * You can also use relative state paths within ui-sref, just like the relative
   * paths passed to `$state.go()`. You just need to be aware that the path is relative
   * to the state that the link lives in, in other words the state that loaded the
   * template containing the link.
   *
   * You can specify options to pass to {@link ui.router.state.$state#methods_go $state.go()}
   * using the `ui-sref-opts` attribute. Options are restricted to `location`, `inherit`,
   * and `reload`.
   *
   * @example
   * Here's an example of how you'd use ui-sref and how it would compile. If you have the
   * following template:
   * <pre>
   * <a ui-sref="home">Home</a> | <a ui-sref="about">About</a> | <a ui-sref="{page: 2}">Next page</a>
   *
   * <ul>
   *     <li ng-repeat="contact in contacts">
   *         <a ui-sref="contacts.detail({ id: contact.id })">{{ contact.name }}</a>
   *     </li>
   * </ul>
   * </pre>
   *
   * Then the compiled html would be (assuming Html5Mode is off and current state is contacts):
   * <pre>
   * <a href="#/home" ui-sref="home">Home</a> | <a href="#/about" ui-sref="about">About</a> | <a href="#/contacts?page=2" ui-sref="{page: 2}">Next page</a>
   *
   * <ul>
   *     <li ng-repeat="contact in contacts">
   *         <a href="#/contacts/1" ui-sref="contacts.detail({ id: contact.id })">Joe</a>
   *     </li>
   *     <li ng-repeat="contact in contacts">
   *         <a href="#/contacts/2" ui-sref="contacts.detail({ id: contact.id })">Alice</a>
   *     </li>
   *     <li ng-repeat="contact in contacts">
   *         <a href="#/contacts/3" ui-sref="contacts.detail({ id: contact.id })">Bob</a>
   *     </li>
   * </ul>
   *
   * <a ui-sref="home" ui-sref-opts="{reload: true}">Home</a>
   * </pre>
   *
   * @param {string} ui-sref 'stateName' can be any valid absolute or relative state
   * @param {Object} ui-sref-opts options to pass to {@link ui.router.state.$state#methods_go $state.go()}
   */
  $StateRefDirective.$inject = ['$state', '$timeout'];
  function $StateRefDirective($state, $timeout) {
    return {
      restrict: 'A',
      require: ['?^uiSrefActive', '?^uiSrefActiveEq'],
      link: function(scope, element, attrs, uiSrefActive) {
        var ref    = parseStateRef(attrs.uiSref, $state.current.name);
        var def    = { state: ref.state, href: null, params: null };
        var type   = getTypeInfo(element);
        var active = uiSrefActive[1] || uiSrefActive[0];
        var unlinkInfoFn = null;
        var hookFn;
  
        def.options = extend(defaultOpts(element, $state), attrs.uiSrefOpts ? scope.$eval(attrs.uiSrefOpts) : {});
  
        var update = function(val) {
          if (val) def.params = angular.copy(val);
          def.href = $state.href(ref.state, def.params, def.options);
  
          if (unlinkInfoFn) unlinkInfoFn();
          if (active) unlinkInfoFn = active.$$addStateInfo(ref.state, def.params);
          if (def.href !== null) attrs.$set(type.attr, def.href);
        };
  
        if (ref.paramExpr) {
          scope.$watch(ref.paramExpr, function(val) { if (val !== def.params) update(val); }, true);
          def.params = angular.copy(scope.$eval(ref.paramExpr));
        }
        update();
  
        if (!type.clickable) return;
        hookFn = clickHook(element, $state, $timeout, type, function() { return def; });
        element.bind("click", hookFn);
        scope.$on('$destroy', function() {
          element.unbind("click", hookFn);
        });
      }
    };
  }
  
  /**
   * @ngdoc directive
   * @name ui.router.state.directive:ui-state
   *
   * @requires ui.router.state.uiSref
   *
   * @restrict A
   *
   * @description
   * Much like ui-sref, but will accept named $scope properties to evaluate for a state definition,
   * params and override options.
   *
   * @param {string} ui-state 'stateName' can be any valid absolute or relative state
   * @param {Object} ui-state-params params to pass to {@link ui.router.state.$state#methods_href $state.href()}
   * @param {Object} ui-state-opts options to pass to {@link ui.router.state.$state#methods_go $state.go()}
   */
  $StateRefDynamicDirective.$inject = ['$state', '$timeout'];
  function $StateRefDynamicDirective($state, $timeout) {
    return {
      restrict: 'A',
      require: ['?^uiSrefActive', '?^uiSrefActiveEq'],
      link: function(scope, element, attrs, uiSrefActive) {
        var type   = getTypeInfo(element);
        var active = uiSrefActive[1] || uiSrefActive[0];
        var group  = [attrs.uiState, attrs.uiStateParams || null, attrs.uiStateOpts || null];
        var watch  = '[' + group.map(function(val) { return val || 'null'; }).join(', ') + ']';
        var def    = { state: null, params: null, options: null, href: null };
        var unlinkInfoFn = null;
        var hookFn;
  
        function runStateRefLink (group) {
          def.state = group[0]; def.params = group[1]; def.options = group[2];
          def.href = $state.href(def.state, def.params, def.options);
  
          if (unlinkInfoFn) unlinkInfoFn();
          if (active) unlinkInfoFn = active.$$addStateInfo(def.state, def.params);
          if (def.href) attrs.$set(type.attr, def.href);
        }
  
        scope.$watch(watch, runStateRefLink, true);
        runStateRefLink(scope.$eval(watch));
  
        if (!type.clickable) return;
        hookFn = clickHook(element, $state, $timeout, type, function() { return def; });
        element.bind("click", hookFn);
        scope.$on('$destroy', function() {
          element.unbind("click", hookFn);
        });
      }
    };
  }
  
  
  /**
   * @ngdoc directive
   * @name ui.router.state.directive:ui-sref-active
   *
   * @requires ui.router.state.$state
   * @requires ui.router.state.$stateParams
   * @requires $interpolate
   *
   * @restrict A
   *
   * @description
   * A directive working alongside ui-sref to add classes to an element when the
   * related ui-sref directive's state is active, and removing them when it is inactive.
   * The primary use-case is to simplify the special appearance of navigation menus
   * relying on `ui-sref`, by having the "active" state's menu button appear different,
   * distinguishing it from the inactive menu items.
   *
   * ui-sref-active can live on the same element as ui-sref or on a parent element. The first
   * ui-sref-active found at the same level or above the ui-sref will be used.
   *
   * Will activate when the ui-sref's target state or any child state is active. If you
   * need to activate only when the ui-sref target state is active and *not* any of
   * it's children, then you will use
   * {@link ui.router.state.directive:ui-sref-active-eq ui-sref-active-eq}
   *
   * @example
   * Given the following template:
   * <pre>
   * <ul>
   *   <li ui-sref-active="active" class="item">
   *     <a href ui-sref="app.user({user: 'bilbobaggins'})">@bilbobaggins</a>
   *   </li>
   * </ul>
   * </pre>
   *
   *
   * When the app state is "app.user" (or any children states), and contains the state parameter "user" with value "bilbobaggins",
   * the resulting HTML will appear as (note the 'active' class):
   * <pre>
   * <ul>
   *   <li ui-sref-active="active" class="item active">
   *     <a ui-sref="app.user({user: 'bilbobaggins'})" href="/users/bilbobaggins">@bilbobaggins</a>
   *   </li>
   * </ul>
   * </pre>
   *
   * The class name is interpolated **once** during the directives link time (any further changes to the
   * interpolated value are ignored).
   *
   * Multiple classes may be specified in a space-separated format:
   * <pre>
   * <ul>
   *   <li ui-sref-active='class1 class2 class3'>
   *     <a ui-sref="app.user">link</a>
   *   </li>
   * </ul>
   * </pre>
   *
   * It is also possible to pass ui-sref-active an expression that evaluates
   * to an object hash, whose keys represent active class names and whose
   * values represent the respective state names/globs.
   * ui-sref-active will match if the current active state **includes** any of
   * the specified state names/globs, even the abstract ones.
   *
   * @Example
   * Given the following template, with "admin" being an abstract state:
   * <pre>
   * <div ui-sref-active="{'active': 'admin.*'}">
   *   <a ui-sref-active="active" ui-sref="admin.roles">Roles</a>
   * </div>
   * </pre>
   *
   * When the current state is "admin.roles" the "active" class will be applied
   * to both the <div> and <a> elements. It is important to note that the state
   * names/globs passed to ui-sref-active shadow the state provided by ui-sref.
   */
  
  /**
   * @ngdoc directive
   * @name ui.router.state.directive:ui-sref-active-eq
   *
   * @requires ui.router.state.$state
   * @requires ui.router.state.$stateParams
   * @requires $interpolate
   *
   * @restrict A
   *
   * @description
   * The same as {@link ui.router.state.directive:ui-sref-active ui-sref-active} but will only activate
   * when the exact target state used in the `ui-sref` is active; no child states.
   *
   */
  $StateRefActiveDirective.$inject = ['$state', '$stateParams', '$interpolate'];
  function $StateRefActiveDirective($state, $stateParams, $interpolate) {
    return  {
      restrict: "A",
      controller: ['$scope', '$element', '$attrs', '$timeout', function ($scope, $element, $attrs, $timeout) {
        var states = [], activeClasses = {}, activeEqClass, uiSrefActive;
  
        // There probably isn't much currentPoint in $observing this
        // uiSrefActive and uiSrefActiveEq share the same directive object with some
        // slight difference in logic routing
        activeEqClass = $interpolate($attrs.uiSrefActiveEq || '', false)($scope);
  
        try {
          uiSrefActive = $scope.$eval($attrs.uiSrefActive);
        } catch (e) {
          // Do nothing. uiSrefActive is not a valid expression.
          // Fall back to using $interpolate below
        }
        uiSrefActive = uiSrefActive || $interpolate($attrs.uiSrefActive || '', false)($scope);
        if (isObject(uiSrefActive)) {
          forEach(uiSrefActive, function(stateOrName, activeClass) {
            if (isString(stateOrName)) {
              var ref = parseStateRef(stateOrName, $state.current.name);
              addState(ref.state, $scope.$eval(ref.paramExpr), activeClass);
            }
          });
        }
  
        // Allow uiSref to communicate with uiSrefActive[Equals]
        this.$$addStateInfo = function (newState, newParams) {
          // we already got an explicit state provided by ui-sref-active, so we
          // shadow the one that comes from ui-sref
          if (isObject(uiSrefActive) && states.length > 0) {
            return;
          }
          var deregister = addState(newState, newParams, uiSrefActive);
          update();
          return deregister;
        };
  
        $scope.$on('$stateChangeSuccess', update);
  
        function addState(stateName, stateParams, activeClass) {
          var state = $state.get(stateName, stateContext($element));
          var stateHash = createStateHash(stateName, stateParams);
  
          var stateInfo = {
            state: state || { name: stateName },
            params: stateParams,
            hash: stateHash
          };
  
          states.push(stateInfo);
          activeClasses[stateHash] = activeClass;
  
          return function removeState() {
            var idx = states.indexOf(stateInfo);
            if (idx !== -1) states.splice(idx, 1);
          };
        }
  
        /**
         * @param {string} state
         * @param {Object|string} [params]
         * @return {string}
         */
        function createStateHash(state, params) {
          if (!isString(state)) {
            throw new Error('state should be a string');
          }
          if (isObject(params)) {
            return state + toJson(params);
          }
          params = $scope.$eval(params);
          if (isObject(params)) {
            return state + toJson(params);
          }
          return state;
        }
  
        // Update route state
        function update() {
          for (var i = 0; i < states.length; i++) {
            if (anyMatch(states[i].state, states[i].params)) {
              addClass($element, activeClasses[states[i].hash]);
            } else {
              removeClass($element, activeClasses[states[i].hash]);
            }
  
            if (exactMatch(states[i].state, states[i].params)) {
              addClass($element, activeEqClass);
            } else {
              removeClass($element, activeEqClass);
            }
          }
        }
  
        function addClass(el, className) { $timeout(function () { el.addClass(className); }); }
        function removeClass(el, className) { el.removeClass(className); }
        function anyMatch(state, params) { return $state.includes(state.name, params); }
        function exactMatch(state, params) { return $state.is(state.name, params); }
  
        update();
      }]
    };
  }
  
  angular.module('ui.router.state')
    .directive('uiSref', $StateRefDirective)
    .directive('uiSrefActive', $StateRefActiveDirective)
    .directive('uiSrefActiveEq', $StateRefActiveDirective)
    .directive('uiState', $StateRefDynamicDirective);
  