I want to create generic feature that allows me to change background image of any section. After going through options provided I found these two approaches. Want to choose best approach to change image because on single page I want multiple times change background facility. It will be available to four to five sections.
Approach
Using Directive check this stack overflow link.
Also there is another approach of angular scope variables that we can updates at runtime.
<div ng-style="{'background-image': 'url(/images/' + backgroundImageUrl + ')'}"></div>
Required Usage ( With respect of Directive )
<body>
<section backgroundImage url="{{backgroundImageUrl1}}">
...
</section>
<section backgroundImage url="{{backgroundImageUrl2}}">
...
</section>
<section backgroundImage url="{{backgroundImageUrl3}}">
...
</section>
<section backgroundImage url="{{backgroundImageUrl4}}">
...
</section>
</body>
As shown above I am going to update background-image attribute for each section. If these property is set inside CSS file, it will reduce time to load images i.e. If we directly add inline css styling in HTML, all images will loaded on DOM load. It will make extra request to server to get images and load them in DOM. I wanted to follow strategy that will reduce loading time in my SPA(Single Page Application).
I think going with <div ng-style="{'background-image': 'url(/images/' + backgroundImageUrl + ')'}"></div> should be more effective.
You dont introduce another layer of complexity, directives create scopes, which are watched and digested, also directives must be compiled in the begining.
Using symple ng-style together with some specific url from controllers property shoudl only do request for that particular active image. Because of that i think it should be the optimal solution.
Related
This is my first post here, usually I can find what I’m looking for before I ask but, if I missed the same question/answer elsewhere sorry. Anyway this is what I have.
I’m working on an Angular project where we have multiple directives not defined on a single DOM like this below(not exactly but a good example)
<div class=”Directive-holder”>
<div Directive-1 ng-show="showDirective1"></div>
<div Directive-2 ng-show="showDirective2"></div>
<div Directive-3 ng-show="showDirective3"></div>
<div Directive-4 ng-show="showDirective5"></div>
(Multiple more below)
</div>
Now when I run the project I need these to load in order
Directive-1
Directive-2
Directive-3
Directive-4
But when they run they run random every reload is there a way to set the order of these to stay 1-4 on every load?
It looks like priority: 0, only work on multiple directives defined on a single DOM,
My page is divided into sections : #page-1 and #page-2
See Plnkr: http://plnkr.co/edit/RZJLmsWDfs63dC0QuDJi
<body>
<section id="page-1">
This is page 1. It takes the whole height of the browser. User has to scroll down to see page-2.
</section>
<section id="page-2">
<span class="animated bounce">This is page 2 </span>
</section>
</body>
Animation classes are being applied to different elements in #page-2.
However by the time the user scrolls down to these elements, the animation has already finished. Hence they just look like static objects.
Is there anyway I can detect when #page-2 is currently being viewed and then call a function to addClass('animated bounce') to certain elements ?
I would like to achieve this in angularjs if possible
I have found a angularjs directive that is probably helpfull for you in this case. Inview tries to solve this exact problem by reporting to you if a dom element is visible on the screen. Unfortunately I have been unable to test my solution because I couldn't find a minified js file of Inview but I assembled some code that should work:
<section id="page-2" in-view="{$inview ? isFocused=true;}">
<div ng-class="{'animated bounce': isFocused}">This is page 2 </div>
</section>
The $inview is supposed to be true whenever the element is in visible in the browser. This leads to the scope variable isFocused being set to true and therefor the animation class is added to your div.
This should work as you have intended in your question, if it does not work for some reason please let me know so I can improve my answer.
How can I show a spinner or loader gif animation while route is changing from one to another.
I am using ng view like as follows:
<div ng-view class="view-animate">
</div>
I am loading templates from server and also inline. While the HTTP request is pending I need to show the spinner/loader... any snippets?
You can show and hide the loader when location change starts and is completed, respectively.
Here is a plunkr that I have created for this situation. This uses ui-router and is taken from one of the apps that I have created, so it may not be useful as-is, but it will give you an idea on how to approach the problem.
HTML Code inserted below just to keep SO happy...
<ui-view class="view"></ui-view>
<div loader="" class="ng-hide"></div>
I hope it helps.
Abhi.
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'm using Angular JS and Angular IU-Router in my project and using a lot of ui-views. I have a situation where I need to change the language of the site, therefore I need to swap my ui-view's model to another model with the relevant language. I already have a service that detects the relevant model and passes it into the ui-view's controller. So if I can reload the ui-view, then in theory my problem would be solved.
I recall reading something about automatically reloading a ui-view (or possibly an ng-view) and re-instantiating its controller, but after much searching I haven't been able to find that information again.
Does anyone know what it is I'm looking for?
1 Take a look at angular-translate
https://github.com/PascalPrecht/angular-translate
2 In your case, add some if-else control ( ng-if, ng-switch etc. ) in the outer div, use the same subview in the inner div. Then change the settings.currentLang when the language changes may cause the subview reload (not tested).
<div ng-controller="containerCtrl">
<div ng-if="settings.currentLang=='en'">
<div ui-view='subview'></div>
</div>
<div ng-if="settings.currentLang=='ja'">
<div ui-view='subview'></div>
</div>
</div>