Share data between AngularJS controllers

A simple solution is to have your factory return an object and let your controllers work with a reference to the same object:

JS:

// declare the app with no dependencies
var myApp = angular.module('myApp', []);

// Create the factory that share the Fact
myApp.factory('Fact', function(){
  return { Field: '' };
});

// Two controllers sharing an object that has a string in it
myApp.controller('FirstCtrl', function( $scope, Fact ){
  $scope.Alpha = Fact;
});

myApp.controller('SecondCtrl', function( $scope, Fact ){
  $scope.Beta = Fact;
});

HTML:

<div ng-controller="FirstCtrl">
    <input type="text" ng-model="Alpha.Field">
    First {{Alpha.Field}}
</div>

<div ng-controller="SecondCtrl">
<input type="text" ng-model="Beta.Field">
    Second {{Beta.Field}}
</div>

Demo: http://jsfiddle.net/HEdJF/

When applications get larger, more complex and harder to test you might not want to expose the entire object from the factory this way, but instead give limited access for example via getters and setters:

myApp.factory('Data', function () {

    var data = {
        FirstName: ''
    };

    return {
        getFirstName: function () {
            return data.FirstName;
        },
        setFirstName: function (firstName) {
            data.FirstName = firstName;
        }
    };
});

With this approach it is up to the consuming controllers to update the factory with new values, and to watch for changes to get them:

myApp.controller('FirstCtrl', function ($scope, Data) {

    $scope.firstName = '';

    $scope.$watch('firstName', function (newValue, oldValue) {
        if (newValue !== oldValue) Data.setFirstName(newValue);
    });
});

myApp.controller('SecondCtrl', function ($scope, Data) {

    $scope.$watch(function () { return Data.getFirstName(); }, function (newValue, oldValue) {
        if (newValue !== oldValue) $scope.firstName = newValue;
    });
});

HTML:

<div ng-controller="FirstCtrl">
  <input type="text" ng-model="firstName">
  <br>Input is : <strong>{{firstName}}</strong>
</div>
<hr>
<div ng-controller="SecondCtrl">
  Input should also be here: {{firstName}}
</div>

Demo: http://jsfiddle.net/27mk1n1o/

I prefer not to use $watch for this. Instead of assigning the entire service to a controller's scope you can assign just the data.

JS:

var myApp = angular.module('myApp', []);

myApp.factory('MyService', function(){
  return {
    data: {
      firstName: '',
      lastName: ''
    }
    // Other methods or objects can go here
  };
});

myApp.controller('FirstCtrl', function($scope, MyService){
  $scope.data = MyService.data;
});

myApp.controller('SecondCtrl', function($scope, MyService){
   $scope.data = MyService.data;
});

HTML:

<div ng-controller="FirstCtrl">
  <input type="text" ng-model="data.firstName">
  <br>Input is : <strong>{{data.firstName}}</strong>
</div>
<hr>
<div ng-controller="SecondCtrl">
  Input should also be here: {{data.firstName}}
</div>

Alternatively you can update the service data with a direct method.

JS:

// A new factory with an update method
myApp.factory('MyService', function(){
  return {
    data: {
      firstName: '',
      lastName: ''
    },
    update: function(first, last) {
      // Improve this method as needed
      this.data.firstName = first;
      this.data.lastName = last;
    }
  };
});

// Your controller can use the service's update method
myApp.controller('SecondCtrl', function($scope, MyService){
   $scope.data = MyService.data;

   $scope.updateData = function(first, last) {
     MyService.update(first, last);
   }
});

There are many ways you can share the data between controllers

1. using services
2. using $state.go services
3. using stateparams
4. using rootscope

Explanation of each method:

1. I am not going to explain as its already explained by someone

2. using $state.go

     $state.go('book.name', {Name: 'XYZ'}); 
   
     // then get parameter out of URL
     $state.params.Name;
   

3. $stateparam works in a similar way to $state.go, you pass it as object from sender controller and collect in receiver controller using stateparam

4. using $rootscope

   (a) sending data from child to parent controller

     $scope.Save(Obj,function(data) {
         $scope.$emit('savedata',data); 
         //pass the data as the second parameter
     });
   
     $scope.$on('savedata',function(event,data) {
         //receive the data as second parameter
     }); 
   

   (b) sending data from parent to child controller

     $scope.SaveDB(Obj,function(data){
         $scope.$broadcast('savedata',data);
     });
   
     $scope.SaveDB(Obj,function(data){`enter code here`
         $rootScope.$broadcast('saveCallback',data);
     });