Sunday, February 12, 2017

AngularJS - Views

AngularJS supports Single Page Application via multiple views on a single page. To do this AngularJS has provided ng-view and ng-template directives and $routeProvider services.

ng-view

ng-view tag simply creates a place holder where a corresponding view (html or ng-template view) can be placed based on the configuration.

Usage

Define a div with ng-view within the main module.
<div ng-app = "mainApp">
   ...
   <div ng-view></div>

</div>    

ng-template

ng-template directive is used to create an html view using script tag. It contains "id" attribute which is used by $routeProvider to map a view with a controller.

Usage

Define a script block with type as ng-template within the main module.
<div ng-app = "mainApp">
   ...
 
   <script type = "text/ng-template" id = "addStudent.htm">
      <h2> Add Student </h2>
      {{message}}
   </script>

</div>    

$routeProvider

$routeProvider is the key service which set the configuration of urls, map them with the corresponding html page or ng-template, and attach a controller with the same.

Usage

Define a script block with main module and set the routing configuration.
var mainApp = angular.module("mainApp", ['ngRoute']);

mainApp.config(['$routeProvider', function($routeProvider) {
   $routeProvider.
   
   when('/addStudent', {
      templateUrl: 'addStudent.htm', controller: 'AddStudentController'
   }).
   
   when('/viewStudents', {
      templateUrl: 'viewStudents.htm', controller: 'ViewStudentsController'
   }).
   
   otherwise({
      redirectTo: '/addStudent'
   });
 
}]);
Following are the important points to be considered in above example.
  • $routeProvider is defined as a function under config of mainApp module using key as '$routeProvider'.
  • $routeProvider.when defines a url "/addStudent" which then is mapped to "addStudent.htm". addStudent.htm should be present in the same path as main html page.If htm page is not defined then ng-template to be used with id="addStudent.htm". We've used ng-template.
  • "otherwise" is used to set the default view.
  • "controller" is used to set the corresponding controller for the view.

Example

Following example will showcase all the above mentioned directives.
testAngularJS.htm
<html>
   
   <head>
      <title>Angular JS Views</title>
      <script src = "https://ajax.googleapis.com/ajax/libs/angularjs/1.3.14/angular.min.js"></script>
      <script src = "https://ajax.googleapis.com/ajax/libs/angularjs/1.3.14/angular-route.min.js"></script>
   </head>
   
   <body>
      <h2>AngularJS Sample Application</h2>
      <div ng-app = "mainApp">
         <p><a href = "#addStudent">Add Student</a></p>
         <p><a href = "#viewStudents">View Students</a></p>
         <div ng-view></div>
         
         <script type = "text/ng-template" id = "addStudent.htm">
            <h2> Add Student </h2>
            {{message}}
         </script>
         
         <script type = "text/ng-template" id = "viewStudents.htm">
            <h2> View Students </h2>
            {{message}}
         </script>
      </div>
      
      <script>
         var mainApp = angular.module("mainApp", ['ngRoute']);
         mainApp.config(['$routeProvider', function($routeProvider) {
            $routeProvider.
            
            when('/addStudent', {
               templateUrl: 'addStudent.htm',
               controller: 'AddStudentController'
            }).
            
            when('/viewStudents', {
               templateUrl: 'viewStudents.htm',
               controller: 'ViewStudentsController'
            }).
            
            otherwise({
               redirectTo: '/addStudent'
            });
         }]);
         
         mainApp.controller('AddStudentController', function($scope) {
            $scope.message = "This page will be used to display add student form";
         });
         
         mainApp.controller('ViewStudentsController', function($scope) {
            $scope.message = "This page will be used to display all the students";
         });
   
      </script>
      
   </body>
</html>

Result

Open textAngularJS.htm in a web browser. See the result.

No comments:

Post a Comment