Odd issue with ng-show always evaluating to true - angularjs

I had a bit of code in my view that would only show up when a particular value was true. Lt looked like this:
button type="button" ng-click="attachBarCode('enter')" ng-show="barcodeAllowed.status">Foo</button>
This was working until recently. My controller had some logic where, based on Ajax data, it would set $scope.barcodeAllowed.status to true. All of a sudden though, the button was always showing up. To help debug the issue, I added some additional tests to my view:
first test, <span ng-show="!barcodeAllowed.status">DONT SHOW</span><br/>
second test, <span ng-show="barcodeAllowed.status">DONT SHOW</span><br/>
test -{{barcodeAllowed.status}}-end -{{!barcodeAllowed.status}}- -{{barcodeAllowed | json}}-<br/>
test if <span ng-if="barcodeAllowed.status"> if was true</span><p>
Here is where things got crazy. Both "DONT SHOWS" rendered in my view, even though it seems as if that would be impossible. When I output the values in the third line, I saw false and true, as I expected.
Finally - the ng-if? It worked perfectly! The value did not show up.
I've heard folks mention that ngShow can have scope issues inside a ngif, but my code isn't inside an ngif.

So, you won't believe what it was. I was using a Content Security policy in my app and on a whim, I disabled it. As soon as I did, it began working. I played around a bit and discovered that I needed to add 'unsafe-eval' to the to the script-src area of my CSP in order for Angular to be able to apply the styles.

The Ng-show/Ng-hide directives needs a css-class to show/hide, since it just adds a class to your element when the scope-variable is truthy/falsy.
Ref: https://docs.angularjs.org/api/ng/directive/ngShow

Related

AngularJS - div still shows even without condition

Ok, I know that title could use some work, but I'm not sure how else to put it.
Here's the setup.
I have a (potentially) massive table that gets generated via an ng-repeat. All the rows need to be editable but, when the dataset is so large, all those bindings slow things to a crawl. I could literally be waiting upwards of 20 seconds for large sets to load!
We noticed that dumping the data in a read-only state significantly decreased the load time. So, we came up with the idea of loading it read-only, but, when the table row was clicked, it became editable. This is accomplished like so. I have two cells output. editableRow is initially false. When the row is clicked, editableRow becomes true. The idea being that, when editableRow becomes true, I see the other cell.
(proprietary code obfuscated)
<TABLE-CELL class="value-col" ng-if="readtime.editableRow === true">
<input type="text"
name="readingTime"
ng-model="<data model>"
ng-disabled="<param>"
ng-change="<function>"
ng-class="<classes>"
/>
</TABLE-CELL>
<TABLE-CELL class="value-col" ng-if="readtime.editableRow === false">
<input type="text"
placeholder="{{<data model>}}"
ng-class="<classes>"
/>
</TABLE-CELL>
The problem is, on the click, for a tiny fraction of a second both cells are visible. It really is only visible on the first click. Subsequent clicks still do it, but it goes so fast that the human eye can't catch it. I know it's there since I slowed everything down with a breakpoint on the mouse click. This also revealed that this happens as the value turns true - turning on the first cell, but the second one doesn't disappear in the same moment. So, it causes a "flicker" of sorts. This seems to happen outside my actual code, inside the jQuery, so I'm not sure how to short circuit it.
I've tried playing with using ng-show/hide instead, which worked a little bit, but also totally negated the time-saving aspect, since it actually renders everything, and it took a long time. I've also tried ng-cloak with no effect whatsoever.
The breakpoint that it keeps stopping on (when I told it to stop on event listeners to do with the mouse click) is the following code in jquery.js:
if ( !(eventHandle = elemData.handle) ) {
eventHandle = elemData.handle = function( e ) {
// Discard the second event of a jQuery.event.trigger() and
// when an event is called after a page has unloaded
return typeof jQuery !== strundefined && jQuery.event.triggered !== e.type ?
jQuery.event.dispatch.apply( elem, arguments ) : undefined;
};
}
It hits that line about 4 times, and, on the last one, both cells are visible. Then, the second one disappears.
I'm out of ideas and would appreciate any thoughts on this.
I finally found an answer that works!
On this page: disable nganimate for some elements the answer right BELOW the accepted answer is what finally worked!
To disable ng-animate for certain elements, using a CSS class, which follows Angular animate paradigm, you can configure ng-animate to test the class using regex.
Config
var myApp = angular.module("MyApp", ["ngAnimate"]);
myApp.config(function($animateProvider) {
$animateProvider.classNameFilter(/^(?:(?!ng-animate-disabled).)*$/);
})
Usage
Simply add the ng-animate-disabled class to any elements you want to be ignored by ng-animate.

Smart admin with ng-repeat

I am using angularjs from 2 months but never comes to problem like this, so thought of sharing with you people and getting some good suggestion on that. Here I am trying to apply ul/nav-group element dynamic values. Everything is working fine means, if I see developer tools on browser it gets value and everything, but not the +/- sign. I search on google its saying that it loads after DOM creation so it is not showing that. But no buddy tells the solution for that.
Consider my code:
<nav:group ng-repeat="parentChild in parentChildList" title="{{parentChild.filterText}}">
<nav:item data-view="/ui/icons/fa" ng-repeat="childs in parentChild.childList" data-icon="fa fa-lg fa-fw fa-plane" title="{{childs.filterText}}" />
</nav:group>
The value for particular fields are straight forward means its simple list.How the directive can solve this problem.
Appreciate any suggestions . Thanks.
Add an ng-cloak directive on the body tag of your app to prevent loading the element until angular has finished loading.
Your body tag would look like this:
<body ng-cloak>
...
</body>
You could also fix this by using promises in your services, that is definitely the best practice regardless, but ng-cloak is a quick and easy fix.
Hope that helps! If ng-cloak doesnt work for you post snippets of your controller and service and I will help you add promises.
Good Luck!
-Justin

Custom Directive inside a Directive Doesn't Fire in IE9

I have a custom directive (to exposecertain fields), and inside that I have another directive (the drop down box for the field). It's working well on Chrome, but on IE9 it appears the ng-show and ng-if is failing to evaluate. It appears not to even enter the function I defined (I put console.log inside the isAllowed function and it appears in Chrome but not in IE9).
<div>
<select id="" class="form-control" ng-model="measure" name="{{name}}">
<option ng-if="isAllowed(name, 1)" value="1">Kilowatt Hours</option>
<option ng-if="isAllowed(name, 2)" value="2">mmBTU</option>
<option ng-if="isAllowed(name, 3)" value="3">Therms</option>
<option ng-if="isAllowed(name, 4)" value="4">Decatherms</option>
</select>
</div>
I have tried ng-show instead of ng-if and it behaves the same in IE9. It appears the replace: true I put on my first directive is not honoured in IE9:
Whereas in Chrome this is replaced as expected with surrounding DIV elements and my custom directives cannot be seen anywhere, which is good.
Has anyone had experience of this before? Is it something to do with having a directive inside of a directive? Seems like IE9 does the first one OK then stops.
(I wish I could drop IE9 but it's an internal app and they're still on IE9 everywhere, so I've got to make it work somehow).
PS: The aim here is to only show the options that are relevant to the given field. In this case Electricity can be measured in kWh and mmBTUs but not in Therms and Decatherms. Inside the isAllowed function is supposed to be some switch logic. It works fine in Chrome, just not IE9, so I might need another method as a workaround.
PPS: Angular 1.3.2. IE9 - Browser Mode: IE9, Document Mode: IE9 Standards.
Figured it out. Isolated scope. Somehow Chrome was dealing with it OK, but IE9 was not.
In my app I have the fields I want to show to my user defined in a Partials module, but the drop-down lists is something I want to use in multiple places and they may change, so I defined them in a directive called BusinessRulesDirectives.
All I needed to do was drop in the BusinessRulesDirectives as a dependency to my Partials module and it works across both Chrome and IE9.
angular.module( 'ActualsPartials', [
'BusinessRulesDirectives'
] )
For some reason Chrome was able to run fine with this, but IE9 did not like it:
angular.module( 'ActualsPartials', [] )
Also, no errors were being output. I just happened to double-check for isolated scope as a wild guess.
Would be interested to know why Chrome was OK but IE9 was not.

toggle skips/misses 2nd sidebar

Today's bogglement! I have two sidebars and a main content area. When I click on a button to expand the page, the sidebars should go away and the main content area spreads to 100%. (I'm trying to do something like what quandl.com does in its api displays, which is totally nifty.)
This should be really simple! I just add a class of 'apponly', which set the main-content to 100% and the sidebars to display:none. In my controller, I've got:
$scope.toggle = function() {
$scope.displayed = !$scope.displayed;
}
and in my html, I've got basically:
<div class="sidebar left" ng-class="{'apponly' : displayed }">
--something something--
</div>
<div class="main-content" ng-class="{'apponly' : displayed }">
<button class="btn btn-info device" ng-click="toggle()">[icon]</button>
--something something--
</div>
<div class="sidebar right" ng-class="{'apponly' : displayed }">
--something something--
</div>
...but it consistently only applies the class 'apponly' to the first sidebar and main content, and leaves the second sidebar intact (wrapped around to the next line, but still right there, w/no class of 'apponly' applied).
I tried to set up a plnk (http://plnkr.co/edit/ER4TPGexGnZ8knb4ThXQ?p=preview) but it won't work at all [okay that was a stupid oversight, now it does work except now I'm even more confused]. What really simple obvious thing am I totally missing here?
many thanks in advance!
AS PSL said, juste update your plunkr to <body ng-app="app" ng-controller="mainController"> and it will work. It actually does what you were expecting, so the issue is probably somewhere else.
Welp, I might as well answer since I (sort of) figured it out, and you never know, I might not be the only one baffled by such behavior.
It's tied to the animation. If you take the animation away, then everything behaves. You add it back in, and things get wacky again.
Why is this? I have no idea. But when I took the animation off the sidebars (so they simply disappear immediately), then the right-hand sidebar doesn't get pushed to the next line and end up remaining despite the added-class that should make it disappear. From behavior at least, it seems that the browser is trying to render animation at the same time the css-class is trying to make the section disappear. Which doesn't make any sense, b/c this works fine in other places, but all I know is that if you leave the animation on the main (middle) part, and turn it off on the sidebars, then everything behaves properly.
I'm not counting this as an answer, though, since it's more of a "well, that fixed it, if inadequately," which is less of an answer and more of a workaround left here for posterity, the enlightenment of any confused devs behind me, and the entertainment of any senior devs wandering through.

Hide Angular brackets until javascript loaded

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>

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