Displaying unique input values with ng-model

Question

Displaying unique input values with ng-model

Within the controller, there is a variable that monitors the page index (starting at 0) for a paginated table:

var page {
  pageNumber: 0;
}

Query: How can I display this pageNumber variable in the HTML, but always incremented by +1? (since the index=0 page represents the first page and should be displayed as Page 1)

<input type="text" ng-model="page.pageNumber">

In addition, when the model is updated, the value in the input field should automatically adjust accordingly (incremented by +1).

javascript angularjs

Answer 1

Answer №1

Utilizing $formatters and $parsers seems like the appropriate approach in this scenario. By manipulating the model's property directly, there is no need to add an extra dummy property. You can refer to the documentation here. Feel free to correct me if this isn't the intended use of $formatters and $parsers.

Take a look at the example below.

HTML code

<body ng-app="app" ng-controller="mainCtrl">   
   {{page}}
   <input paginated-index type="text" ng-model="page">   
</body>

JavaScript

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

app.controller('mainCtrl', function($scope) {
  $scope.page = 0;
});

app.directive('paginatedIndex', function()
{
    return{
        restrict: 'A',
        require: 'ngModel',
        link: function(scope, element, attrs, ngModelController)
        {
            ngModelController.$formatters.push(function(value)
            {
                return value+1;
            })

            ngModelController.$parsers.push(function(value)
            {
                return value-1;
            })   
        }
    }
});

Answer 2

Utilizing $formatters and $parsers seems like the appropriate approach in this scenario. By manipulating the model's property directly, there is no need to add an extra dummy property. You can refer to the documentation here. Feel free to correct me if this isn't the intended use of $formatters and $parsers.

Take a look at the example below.

HTML code

<body ng-app="app" ng-controller="mainCtrl">   
   {{page}}
   <input paginated-index type="text" ng-model="page">   
</body>

JavaScript

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

app.controller('mainCtrl', function($scope) {
  $scope.page = 0;
});

app.directive('paginatedIndex', function()
{
    return{
        restrict: 'A',
        require: 'ngModel',
        link: function(scope, element, attrs, ngModelController)
        {
            ngModelController.$formatters.push(function(value)
            {
                return value+1;
            })

            ngModelController.$parsers.push(function(value)
            {
                return value-1;
            })   
        }
    }
});

Answer 3

Answer №2

To update your controller, modify the page object like this:

$scope.page = {
  displayedPage: function(num) {
    if(arguments.length) {
       $scope.page.pageNumber = num - 1;
       return num;
    } else {
      return $scope.page.pageNumber + 1;
    }
  },
  pageNumber: 0
}

Next, adjust your element to the following:

<input type="text" ng-model="page.displayedPage" ng-model-options="{ getterSetter: true}" />

This will display the incremented page number while maintaining the correct value of the actual page.pageNumber variable.

The use of getterSetter: true in the ng-model-options binds the model to a getter/setter function, enabling you to input values and retrieve them from that function. For more details, refer to the documentation for ngModel.

Answer 4

To update your controller, modify the page object like this:

$scope.page = {
  displayedPage: function(num) {
    if(arguments.length) {
       $scope.page.pageNumber = num - 1;
       return num;
    } else {
      return $scope.page.pageNumber + 1;
    }
  },
  pageNumber: 0
}

Next, adjust your element to the following:

<input type="text" ng-model="page.displayedPage" ng-model-options="{ getterSetter: true}" />

This will display the incremented page number while maintaining the correct value of the actual page.pageNumber variable.

The use of getterSetter: true in the ng-model-options binds the model to a getter/setter function, enabling you to input values and retrieve them from that function. For more details, refer to the documentation for ngModel.

Answer 5

Answer №3

Here is a simple way to achieve this.

   $scope.data=$scope.page.pageNumber+1;
   $scope.changePage=function(){
      $scope.page.pageNumber=$scope.data-1;

   };

Your HTML code should look like this:

    <input type="text"  ng-model="data" ng-change="changePage()" >

For more details, please see this example on Plunker.

Answer 6

Here is a simple way to achieve this.

   $scope.data=$scope.page.pageNumber+1;
   $scope.changePage=function(){
      $scope.page.pageNumber=$scope.data-1;

   };

Your HTML code should look like this:

    <input type="text"  ng-model="data" ng-change="changePage()" >

For more details, please see this example on Plunker.

Displaying unique input values with ng-model

Answer №1

Answer №2

Answer №3

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