Angularjs ui-router add parent url parameter to current state - angularjs

Question

This is my app state
.state('app', {
url: "/?:site_id",
templateUrl: "/controls/angular/templates/partial/app.html",
abstract: true
})
.state('app.popup', {
url: "popup",
templateUrl: "/controls/angular/templates/popup.html",
controller: 'PopupController'
})
The app root (that config as abstract) has parameter (site_id) that I can use in all other pages in the application.
I have drop-down list that can change the site.
How can I add the site url parameter to current page with all other parameters that exist
Just change the root site_id parameter.
var oSelect = $('#site_select_tag').select2();
oSelect.on("change", function (e) {
var curr_site_id = e.val;
$state.go to => ?????????
//scope.site_id = e.val;
scope.onChange()(e.val);
});

Answer 1

Thanks
The solution is simple
$state.go('.', {site_id: e.val})
Keep all other parameters and set the new parameter

Answer 2

You can pass options to the go method of $state:
$state.go(to [, toParams] [, options])
https://github.com/angular-ui/ui-router/wiki/Quick-Reference#stategoto--toparams--options
$state.go('myState', {'myParam': myValue});
And you can set parameters on ui-sref:
ui-sref='stateName({param: value, param: value})'
https://github.com/angular-ui/ui-router/wiki/Quick-Reference#ui-sref
<a ui-sref="myState({'myParam': myValue})">myLink</a>
You can access the current state as $state.current.name and the current parameters as $state.params so what you can do is this:
var params = $state.params;
params.id = 123; // Set new ID
$state.go($state.current.name, params);

Answer 3

If I understand you correctly your trying to manipulate the state data after it is set up in the $stateProvider. If so you should set up your own state provider like Mean.io do
// $meanStateProvider, provider to wire up $viewPathProvider to $stateProvider
angular.module('mean.system').provider('$meanState', ['$stateProvider', '$viewPathProvider', function($stateProvider,viewPathProvider){
function MeanStateProvider() {
this.state = function(stateName, data) {
if (data.templateUrl) {
data.templateUrl = $viewPathProvider.path(data.templateUrl);
}
$stateProvider.state(stateName, data);
return this;
};
this.$get = function() {
return this;
};
}
return new MeanStateProvider();
}]);