angular ng-if or ng-show responds slow (2second delay?)

AngularjsAngularjs DirectiveIonic Framework

Angularjs Problem Overview


I'm trying to show or hide a loading indicator on a button when a request is busy. I do that with angular by changing the $scope.loading variable when a request is loading or when it's done loading.

 $scope.login = function(){
     $scope.loading = true;
 	apiFactory.getToken()
 		.success(function(data){
 			
 		})
 		.error(function(error){
 			
 		})
         .finally(function(){
               $timeout(function() {
                 $scope.loading = false;
               }, 0);
         });
 };

In the frontend:

<button ng-disabled="loading" class="button button-outline button-positive" type="submit">
Log in 
<span ng-if="loading" class="ion-refreshing"></span>
</button>

This works fine, but the loading icon (ion-refreshing) is shown for about 2 seconds, while the $scope variable is updated immediately. I tried $scope.$apply but that doesn't seem to be what's wrong here, the scope is updated just fine and immediately after the request. It's just the icon that isn't responding quickly enough.

Angularjs Solutions


Solution 1 - Angularjs

Try removing ngAnimate if you're not using it from your app config and index.html page:

angular.module('myApp', [...'ngAnimate',...])

@Spock; if you still require the use of ngAnimate then leave your app config untouched and just add the following CSS:

.ng-hide.ng-hide-animate{
     display: none !important;
}

That will hide the animated icon straight after your condition is met.

As you can see we are setting .ng-hide-animate to hidden. This is what causes the delay as it waits for the animation to complete. You can add an animation to your hide event as the class name implies instead of hiding it as in the example above.

Solution 2 - Angularjs

I had the same issue, and worked-around it by using ng-class with the 'hidden' class name to hide the element instead of using ng-if or ng-show/ng-hide.

Solution 3 - Angularjs

I found some solutions here, but the best for me was overriding the styling for the .ng-animate class:

.ng-animate.no-animate {
    transition: 0s none;
    -webkit-transition: 0s none;
    animation: 0s none;
    -webkit-animation: 0s none;
}

In html:

<button ng-disabled="loading" class="button button-outline button-positive" type="submit">
    Log in 
    <span ng-if="loading" class="ion-refreshing no-animate"></span>
</button>

This is an example: http://jsfiddle.net/9krLr/27/

I hope help you.

Solution 4 - Angularjs

I was facing a similar issue, I used $scope.$evalAsync() to force update the binding.

It works like a charm.

Avoid using $scope.$apply as it can conflict with an already-running $digest phase.

if(selectedStatistics.length === 0 || selectedWorkgroups.length === 0){
    ctrl.isSaveDisabled = true;
    $scope.$evalAsync();
} else{
    ctrl.isSaveDisabled = false;
    $scope.$evalAsync();
}

Solution 5 - Angularjs

I had the same issue when using

<div *ngIf='shouldShow'>
    <!-- Rest of DIV content here -->
</div>

In my case I solved it by adding a class:

.hidden {
  display: none;
}

and then adding the class conditionally instead of using *ngIf:

<div [ngClass]="{'hidden': !shouldShow}">
    <!-- Rest of DIV content here -->
</div>

If always using it this way, I would consider renaming shouldShow to shouldHide (and negate the logic that assigns it), so it can be used as shouldHide instead of !shouldShow.

If you have display: flex in your CSS for the DIV's existing class, that display property might take precedence over the display: hidden. An easy fix can be to use display: none !important instead, but there are often better solutions to ensure precedence in other ways. Here is a good read about alternatives.

Solution 6 - Angularjs

in angular version 1.5.x adding $scope.$apply() after the change in the condition done the job for me here is an example function

$scope.addSample = function(PDF)
        {
            var validTypes ="application/pdf";
            if(PDF.type == validTypes)
            {
                //checking if the type is Pdf and only pdf
                $scope.samplePDF= PDF.files[0];
                $scope.validError = false;
                $scope.$apply();
            }

            else
            {
                 $scope.validError = true;
                 $scope.samplePDF= null;
                 $scope.$apply();
            }

        	
        }

Solution 7 - Angularjs

I ended up using Ruben's solution but because I can't afford to add an extra class to all existing cases, I listed the directives I am always using without animations, expecting immediate rendering:

*[ng-hide],
*[ng-show],
*[ng-if],
*[ng-switch-when],
*[ng-switch-default] {
  transition: 0s none;
  -webkit-transition: 0s none;
  animation: 0s none;
  -webkit-animation: 0s none;
}

Attributions

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Content TypeOriginal AuthorOriginal Content on Stackoverflow
QuestionJorreView Question on Stackoverflow
Solution 1 - AngularjsPalvinderView Answer on Stackoverflow
Solution 2 - AngularjsneimadView Answer on Stackoverflow
Solution 3 - AngularjsRuben PerezView Answer on Stackoverflow
Solution 4 - AngularjspixlboyView Answer on Stackoverflow
Solution 5 - AngularjsKent Munthe CaspersenView Answer on Stackoverflow
Solution 6 - AngularjsmohamedView Answer on Stackoverflow
Solution 7 - AngularjsjsruokView Answer on Stackoverflow