How to pass parameters using ui-sref in ui-router to controller

I need to pass and recieve two parameters to the state I want to transit to using ui-sref of ui-router.

Something like using the link below for transitioning the state to home with foo and bar parameters:

<a ui-sref="home({foo: 'fooVal', bar: 'barVal'})">Go to home state with foo and bar parameters </a>

Receiving foo and bar values in a controller:

app.controller('SomeController', function($scope, $stateParam) {
  //..
  var foo = $stateParam.foo; //getting fooVal
  var bar = $stateParam.bar; //getting barVal
  //..
});     

I get undefined for $stateParam in the controller.

Could somebody help me understand how to get it done?

Edit:

.state('home', {
  url: '/',
  views: {
    '': {
      templateUrl: 'home.html',
      controller: 'MainRootCtrl'

    },

    'A@home': {
      templateUrl: 'a.html',
      controller: 'MainCtrl'
    },

    'B@home': {
      templateUrl: 'b.html',
      controller: 'SomeController'
    }
  }

});

I've created an example to show how to. Updated state definition would be:

  $stateProvider
    .state('home', {
      url: '/:foo?bar',
      views: {
        '': {
          templateUrl: 'tpl.home.html',
          controller: 'MainRootCtrl'

        },
        ...
      }

And this would be the controller:

.controller('MainRootCtrl', function($scope, $state, $stateParams) {
    //..
    var foo = $stateParams.foo; //getting fooVal
    var bar = $stateParams.bar; //getting barVal
    //..
    $scope.state = $state.current
    $scope.params = $stateParams; 
})

What we can see is that the state home now has url defined as:

url: '/:foo?bar',

which means, that the params in url are expected as

/fooVal?bar=barValue

These two links will correctly pass arguments into the controller:

<a ui-sref="home({foo: 'fooVal1', bar: 'barVal1'})">
<a ui-sref="home({foo: 'fooVal2', bar: 'barVal2'})">

Also, the controller does consume $stateParams instead of $stateParam.

Link to doc:

• URL Parameters

You can check it here

params : {}

There is also new, more granular setting params : {}. As we've already seen, we can declare parameters as part of url. But with params : {} configuration - we can extend this definition or even introduce paramters which are not part of the url:

.state('other', {
    url: '/other/:foo?bar',
    params: { 
        // here we define default value for foo
        // we also set squash to false, to force injecting
        // even the default value into url
        foo: {
          value: 'defaultValue',
          squash: false,
        },
        // this parameter is now array
        // we can pass more items, and expect them as []
        bar : { 
          array : true,
        },
        // this param is not part of url
        // it could be passed with $state.go or ui-sref 
        hiddenParam: 'YES',
      },
    ...

Settings available for params are described in the documentation of the $stateProvider

Below is just an extract

• value - {object|function=}: specifies the default value for this parameter. This implicitly sets this parameter as optional...
• array - {boolean=}: (default: false) If true, the param value will be treated as an array of values.
• squash - {bool|string=}: squash configures how a default parameter value is represented in the URL when the current parameter value is the same as the default value.

We can call these params this way:

// hidden param cannot be passed via url
<a href="#/other/fooVal?bar=1&amp;bar=2">
// default foo is skipped
<a ui-sref="other({bar: [4,5]})">

Check it in action here

You don't necessarily need to have the parameters inside the URL.

For instance, with:

$stateProvider
.state('home', {
  url: '/',
  views: {
    '': {
      templateUrl: 'home.html',
      controller: 'MainRootCtrl'

    },
  },
  params: {
    foo: null,
    bar: null
  }
})

You will be able to send parameters to the state, using either:

$state.go('home', {foo: true, bar: 1});
// or
<a ui-sref="home({foo: true, bar: 1})">Go!</a>

Of course, if you reload the page once on the home state, you will loose the state parameters, as they are not stored anywhere.

A full description of this behavior is documented here, under the params row in the state(name, stateConfig) section.

You simply misspelled $stateParam, it should be $stateParams (with an s). That's why you get undefined ;)