I'm fixing a bug on some legacy Angular 1.5 code.
I have a template like this
<div id="container" ng-if="ctrl.show_container">
<div id="child"></div>
</div>
I need to manipulate the div#child. I'm using $element.find() to get the child div. Unfortunately, it seems that code runs before the template/DOM has finished rendering -- due to the conditional rendering on the container, it doesn't find anything. If I remove the ng-if, it's able to find the element as expected.
Is there any way I can execute my DOM manipulation until after all the conditional rendering is done?
Thank you
If simple case you just do:
ctrl.show_container = true;
$timeout(() => $element.find(...))
If that is not enough you'd better add some directive on that #child element.
scope.$watch('$viewContentLoaded', functionToManipulateDom)
Related
I would like to write an ng-if expression with Ui Router in Angular, so that it would be triggered always that the state doesn't match one state in particular.
Something like $state.is(!'notThisState')
Thanks in advance!
I think what you're looking for is:
<div ng-if="$state.current.name !== 'notThisState'">
Your div goes here.
</div>
Here is my issue:
I am using ng-repeat to make a list of spans.
Each span has the contenteditable attribute and ng-model directive.
Everything works as expected (including two-way data binding), until I try to add a new item to the list.
<div ng-repeat="item in list">
<span ng-model="item.text" contenteditable></span>
</div>
<button ng-click="addItemToList"></button>
The methods look like this:
$scope.addItemToList = function () {
$scope.list.push({text: 'dummy text'});
}
or
$scope.addItemToList = function () {
$scope.list.splice(1, 0, {text: 'dummy text'});
}
When adding the new item to the list (push or splice), the DOM updates, but the last item is initialised empty, with no text whatsoever. The last item in the model list also empties out, even if I specifically push an element with text in it.
After a few tests, I've noticed that this only happens if the list's length is bigger after modifying it:
if I try to replace/modify/remove (not add) an element in the list, it works well.
I believe this has to do with the way contenteditable elements initialise in the DOM (I think they initialise empty, and somehow, the model empties out as well).
Has anyone encountered this problem before? If yes, how did you solve it / what workaround have you found?
Based on the angular docs related to ngModelController, it seems that there is not built-in support for two-way data binding with contenteditable elements, seeing as in the plunkr example they wrote their own contenteditable directive. You might be able to use a modified version of that as a workaround.
It looks to be a similar problem as this question and the contenteditable directive there looks similar to the contenteditable directive in the angular docs example.
I also found this directive on github that might accomplish what you are trying to do.
Edit: I did a new version of the plunk I posted in the comment above:
https://plnkr.co/edit/v3elswolP9AgWHDIPwCk
In this version I added a contenteditable directive that appears to be working correctly. It is basically a spin off of how the input[type=text] directive is written in angular, but I took out the places where it handles different types of input (since in this case it will just be text) and the places where it handles events that contenteditable elements don't even fire. I also changed it so that the $viewValue gets updated based on element.html() instead of element.val(). You might be able to use something like this as a workaround
The issue is old but that was the same problem for me today. (angular 1.5). My workaround was to add on blur update option: <td contenteditable data-ng-model="position.value" ng-model-options="{updateOn: 'blur'}"></td> somehow then model stopped getting be empty on initialize. I like using update on blur in many places (solves some performaces issues) so this is good for me, however it's some kind of trick.
In my AngularJS I have the following code where I check if there is a currently logged in user or not in order to switch the top app menu text from Login to Logout (login if no user is logged in) and vice versa. When I used ng-show ng-hide the app started to be extremely heavy so I tried switching to ng-if, but then the css effects on the top menu started not to work specifically in the login/ logout tab. So can someone please tell me what is the best approach to handle this situation with example please? Thanks
index.html
<div ng-controller="MenuController">
<li>
<div ng-if="userLevel() == 1">
Login
</div>
<div ng-if="userLevel() == 2">
Logout
</div>
</li>
</ul>
</div>
Controller:
controller('MenuController',
function MenuController($scope, UService){
$scope.userLevel = function(){
var userType = UService.checkULevel(); //This will return either 1, 2,3,4...etc
return userType;
};
});
The difference between ng-show and ng-if is that ng-show applies a display: none to the element when the specified expression is a false value, while the ng-if removes the node from the DOM, basically equivalent to the .empty in jQuery.
An approach you can consider for your element, is rather than using it within a controller, use a directive for the access level, and follow the approach described in this article, which is really flexible and allows you to have different elements in the UI depending on the user level: http://frederiknakstad.com/2013/01/21/authentication-in-single-page-applications-with-angular-js/
Another reason for your application to be slow when you check the user level, could be that every time that is evaluated your application has to perform a check on the server side, slowing the application. An approach for it would be to cache the result of that query, and then use it while the login status doesnt change. At that stage you can invalidate the cache and fetch the user level again, ready to update the UI.
The ng-if directive removes the content from the page and ng-show/ng-hide uses the CSS display property to hide content.
I am pretty sure that no-show is lighter than ng-if and no-show should not make the app too heavy. If it is becoming heavy, I think there could be other causes for it.
If you use ng-if the node is rendered only when the condition is true
In case of ng-show ng-hide the Nodes will be rendered but shown/hidden based on the condition if condition changes the same nodes are shown/hidden
when ever you use ng-if it will render only that code which satisfy the condition.
while ng-show ng-hide will render the code on page but will be hidden with the help of CSS properties.
so better to use ng-if for reducing the line of code to be rendered on page.
I have a few bits of HTML like
<p class="noresults">{{numberOfContacts}} Results Are Available</p>
Is it possible for me to hide {{numberOfContacts}} until Angular has loaded? So it would just say Results Are Available
I've seem some solutions such as hiding the entire body until Angular has loaded, but I'd rather not do that if possible.
Yes, use ng-cloak. Simply add class="ng-cloak" or ng-cloak to an element like this
Using directive <div ng-cloak></div>
Using class <div class="ng-cloak"></div>
It's simply a set of CSS rules with display: none !important and as Angular has rendered your DOM it removes the ng-cloak so an element is visible.
use <span ng-bind="numberOfContacts" /> instead of {{numberOfContacts}}
Sometimes, even if I used the ng-cloak, I could still see the braces for a few seconds. Adding the following style resolved my issue:
[ng-cloak]
{
display: none !important;
}
Please see this link link for more explanation.
Hope it helps :D
This is typically only an issue when working with complex content on really slow devices. In those instances, there can be a brief moment when the browser displays the HTML in the document while AngularJS is parsing the HTML, getting ready, and processing the directives. In this interval of time, any inline template expressions you have defined will be visible to the user. Most devices nowadays have pretty good browsers which are quick enough to prevent this from being an issue. There are two ways to solve the problem.
Avoid using inline template expressions and stick with ng-bind directive.
(Best) Use the ng-cloak directive which will hide the content until Angular has finished processing it. Basically, the ng-cloak directive uses CSS to hide the elements and angular removes the CSS class when the content has been processed, ensuring that the user never sees the {{ and }} characters of a template expression.
One strategy to consider is using the ng-cloak directly to the body element, which will ensure that the user will see an empty browser while AngularJS loads. However, you can be more specific by applying it to parts of the document where there are inline expressions.
I have seen issues with ng-cloak not working when added to an element. In the past, I have worked around this issue by simply adding ng-cloak class to element.
You can use ng-bind instead of expression like
<span ng-bind="data"></span>
I have been working with routing and I have seen how I can update the ng-view using routing and a view template.. But the problem I have is that I am doing a REST call and depending what I get back from the response I wish to update part of the DOM with a view template but I don't want to involve routing.
Does anyone know how I can do this? Or any examples would be great
Thanks in advance
Another answer. Based on your description in the comment, it sounds like you wish to display part of the DOM conditionally.
When you want to display part of the DOM conditionally, you have the following choices:
Use an ng-show and ng-hide directive.
Based on what returns from the RESTful call, you can set up a model that will identify the DOM that needs to be displayed. An example:
<div ng-show="status">
This text will be shown only when the status is truthy
</div>
<div ng-hide="status">
This text will be shown only when the status is false.
</div>
Inside your controller, you could then set the status to true or false based on your RESTful calls and based on which part of the DOM you wish to display post RESTful call.
You can use ng-switch directive
While the ng-show and ng-hide directives will display the content of your DOM conditionally, that is anybody could simply open the source file and see the contents for both, ng-switch directive will load the contents only based on which case fulfills the swtich. An example:
<div ng-switch on="status">
<div ng-switch-when="true">
This text will be shown only when the status is truthy.
Else this is completely hidden and cannot be seen even
when looking at the source.
</div>
<div ng-switch-when="false">
This text will be shown only when the status is false.
Else this is completely hidden and cannot be seen even
when looking at the source.
</div>
</div>
The first child div is shown when the status is true else it is not shown at all. The advantage over ng-show or ng-hide is that the DOM will not contain the child elements if the case is not fulfilled.
$location.path() can be used here.
So, in your Parent Controller, you can make the REST call. Once you have the data with you, you can then decide which route to take. The route value goes into the path() function.
As an example, let us say that if your REST call returns with cherries, you need to take the /foo path (which, based on your $routeProvider will load the template associated with that route). You can then write the following:
$location.path('/foo');
and it will loads the /foo path - $routeProvider will then take care of loading the template associated with that path.
Reference: $location