How to prevent redundancy in Angular code while utilizing `ng-if`

Question

How to prevent redundancy in Angular code while utilizing `ng-if`

Here is my current implementation:

<div class="outer-class" ng-repeat="item in items">
  <div class="inner-class" ng-if="isShow">
    <div class="inner-class-1">{{item}}</div>
  </div>
  <div ng-if="!isShow" class="inner-class-1">{{item}}</div>
</div>

While the above code is functional, it contains a significant amount of repetition:

The ng-if directive is typed out twice (ng-switch isn't a viable alternative since it introduces another element)
The
```
<div ng-if="!isShow" class="inner-class-1">{{item}}</div>
```
segment is duplicated to prevent the encapsulating of data when the ng-if condition is false.

I am contemplating whether there is a more effective way to rewrite the code while achieving the same outcome.

javascript angularjs

Answer 1

Answer №1

To improve the situation, it would be wise to develop a personalized directive that can selectively encapsulate content. Consider implementing something similar to the following code:

angular.module('example', []).controller('ExampleController', function($scope) {
  $scope.items = [1, 2, 3];
  $scope.isShown = false;
})

.directive('wrapIf', function() {
  return {
    restrict: 'A',
    transclude: true,
    link: function(scope, element, attrs, controller, transclude) {

      var previousContent;

      scope.$watch(attrs.wrapIf, function(newVal) {
        if (newVal) {
          previousContent.parent().append(element);
          element.empty().append(previousContent);
        } else {
          transclude(function(clone, scope) {
            previousContent = clone;
            element.replaceWith(clone);
          });
        }
      })
    }
  };
});

.inner-class, .inner-class-1 {
  padding: 6px;
  background: #DDD;
}
.inner-class-1 {
  background: #34dac3;
}
.outer-class {
  margin-bottom: 6px;
}

<script src="https://code.angularjs.org/1.4.8/angular.js"></script>

<div ng-app="example" ng-controller="ExampleController">

  <p>
    <button ng-click="isShown = !isShown">Toggle isShown ({{ isShown }})</button>
  </p>

  <div class="outer-class" ng-repeat="item in items">
    <div class="inner-class" wrap-if="isShown">
      <div class="inner-class-1" ng-click="sample(item)">{{item}}</div>
    </div>
  </div>

</div>

Answer 2

To improve the situation, it would be wise to develop a personalized directive that can selectively encapsulate content. Consider implementing something similar to the following code:

angular.module('example', []).controller('ExampleController', function($scope) {
  $scope.items = [1, 2, 3];
  $scope.isShown = false;
})

.directive('wrapIf', function() {
  return {
    restrict: 'A',
    transclude: true,
    link: function(scope, element, attrs, controller, transclude) {

      var previousContent;

      scope.$watch(attrs.wrapIf, function(newVal) {
        if (newVal) {
          previousContent.parent().append(element);
          element.empty().append(previousContent);
        } else {
          transclude(function(clone, scope) {
            previousContent = clone;
            element.replaceWith(clone);
          });
        }
      })
    }
  };
});

.inner-class, .inner-class-1 {
  padding: 6px;
  background: #DDD;
}
.inner-class-1 {
  background: #34dac3;
}
.outer-class {
  margin-bottom: 6px;
}

<script src="https://code.angularjs.org/1.4.8/angular.js"></script>

<div ng-app="example" ng-controller="ExampleController">

  <p>
    <button ng-click="isShown = !isShown">Toggle isShown ({{ isShown }})</button>
  </p>

  <div class="outer-class" ng-repeat="item in items">
    <div class="inner-class" wrap-if="isShown">
      <div class="inner-class-1" ng-click="sample(item)">{{item}}</div>
    </div>
  </div>

</div>

Answer 3

Answer №2

Perhaps a solution along these lines?

//custom wrapper function

function generateCustomTemplate(element, attributes) {
  if (attributes.showWrapper){
    return "<div ng-class='wrapperClass' ng-transclude></div>"
  }
  else return "<ng-transclude></ng-transclude>";
}

app.directive('customWrapperDirective', function() {
    return {
        restrict: 'E',
        transclude: true,
        template: generateCustomTemplate,
        link: function($scope, element, attrs) {
          $scope.wrapperClass = attrs.wrapperClass;
        }
    };
});

Usage example:

<custom-wrapper-directive wrapper-class='inner-class-1' show-wrapper='isShow'></custom-wrapper-directive>

Answer 4

Perhaps a solution along these lines?

//custom wrapper function

function generateCustomTemplate(element, attributes) {
  if (attributes.showWrapper){
    return "<div ng-class='wrapperClass' ng-transclude></div>"
  }
  else return "<ng-transclude></ng-transclude>";
}

app.directive('customWrapperDirective', function() {
    return {
        restrict: 'E',
        transclude: true,
        template: generateCustomTemplate,
        link: function($scope, element, attrs) {
          $scope.wrapperClass = attrs.wrapperClass;
        }
    };
});

Usage example:

<custom-wrapper-directive wrapper-class='inner-class-1' show-wrapper='isShow'></custom-wrapper-directive>

How to prevent redundancy in Angular code while utilizing `ng-if`

Answer №1

Answer №2

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