Target: I need to decide the bottom position of an element once the page loads.
What I tried: componentDidMount() life cycle method, which turned out to run after only the HTML markup is set, so the position value was wrong because the layout wasn't implemented yet.
Solved it with JS window.onload.
The load event is fired when the whole page has loaded, including all dependent resources such as stylesheets images - mdn
Related
I am trying to work out how some code is working, it uses angular throughout the front end.
When the page first loads a div with ng-include should be in the dom but its src url is a call to a js function that returns undefined on page load.
<div id="test_div" ng-include="getUrl()"></div>
When I check the dom the entire element is not on the page. After a search button is pressed some other calls happen and the call to getUrl() will return a valid url from that point on, which returns html content from the server.
It is only then that the div appears in the dom and it now has a class added to it of class="ng-scope".
I dont understand how this is happening, does ng-include continue to request a resource until it is avilable?
I couldnt find this information in the documentation.
I have some problems using Material Design Lite (getmdl.io). I followed the steps showed in the getmdl.io web in order to install it (actually I use bower), but I always have the same problem, when I change the ng-route in my web, some resources don't render properly, I need to reload the page to get it properly rendered, for example.
First I have this:
then when I reload, I get what I want:
What I cant understand is why other resources like google icons or buttons work correctly but the menu button on the nav bar and other resources like this one need to reaload the page in order to render properly.
I try to include the library using the hosted method and bower method.
Any idea what is going on?
i past in my code this function
angular.module('app', ['ngRoute']).
run(function($rootScope, xxxx, xxx){
$rootScope.$on('$viewContentLoaded', function(event, next) {
componentHandler.upgradeAllRegistered();
});
});
It worked perfect! Good luck..
Libraries like MDL work by waiting for the page to load using the DOMContentLoaded event, scanning the page for things like input elements and manipulating them with JavaScript so that they can inject the bits and pieces needed to work with their components. This works fine on static websites, but the DOMContentLoaded event only fires once, so when Angular performs a page transition, the DOM changes without MDL knowing about it.
Material Design Lite has a section in its FAQ about using MDL on dynamic websites:
Material Design Lite will automatically register and render all elements marked with MDL classes upon page load. However in the case where you are creating DOM elements dynamically you need to register new elements using the upgradeElement function. Here is how you can dynamically create the same raised button with ripples shown in the section above:
<div id="container"/>
<script>
var button = document.createElement('button');
var textNode = document.createTextNode('Click Me!');
button.appendChild(textNode);
button.className = 'mdl-button mdl-js-button mdl-js-ripple-effect';
componentHandler.upgradeElement(button);
document.getElementById('container').appendChild(button);
</script>
Of course, this probably isn't terribly easy to do in your case, since you'd have to manually find each new element and call upgradeElement on it.
Usually, instead of doing this sort of event-based DOM manipulation, Angular uses directives to initiate DOM changes. Consider using a library built to interoperate with Angular, instead, such as Angular Material.
I'm working on an app whose header's styling and UI options will change depending upon the state a user is currently in. For example, if a user clicks the Upload, Edit Profile, Create Playlist or Create Gallery buttons in the main menu, this will cause the following changes to the header:
the header's background to change color
the site logo will have CSS3 animation applied to it to make it slide into a new position
a specific message (depending on what state the user is in) in a word bubble will appear next to the logo
a Cancel button will manifest on the right edge of the header
This means there will be no static element on my site so logic tells me that I should place ui-view in my body tag thus making it look like this:
<body ng-app="app" ui-view>
I have never seen that used before anywhere so I've my doubts. Any ideas?
I'm not sure if this will or will not work technically, but I believe you should avoid it because:
It would require all your templates to include an outermost <body> tag which makes them less reusable
It's generally an unusual thing to do, and that comes with a cost, and I see no particular benefit to this, so IMHO the cost/benefit analysis says stick with what is conventional: use <div>s.
I suspect this may in fact work, but typically the tag with ng-app stays in place for the entire lifecycle of the app. There's a chance you may hit some weird errors if you swap out the tag containing ng-app. Thus many people put ng-app on the very first <html> tag and call it done.
But it's your app and the effort to try both approaches is very low, so just try them out and see (and let us know what you learn). I don't think you need to wait for stackoverflow answer from authority to test 2 slightly different HTML structures with your app.
No, please do not do that!
Having ui-view inside of the body tag may render many JS plugins/libraries unusable, especially in case if they dynamically add some HTML tags to document.body. In such cases, navigation to another view will reinitialize document.body and thus disregard previously added HTML tags.
E.g. this is the case with Firebase and Angular.js (AngularFire). I hope everybody who has come across the error
Uncaught NotFoundError: Failed to execute 'removeChild' on 'Node': The node to be removed is not a child of this node.
will get to see this post. Just make sure you haven't added ui-view attribute to your body tag.
I'm using Angular UI router in my app. This is what I'm doing.
A main view contains a child view and a div container for "pagination"
By default, initially, a first set of contents is loaded
When a user clicks on "next page", next set of contents is loaded (with the URL also being changed to /content/2 (where 2 indicates the next page number)
All is working well, but each time the contents are loaded, it goes "blank" before it loads. So it seems like it's reloading the view (which is obvious).
What I would like to do is reload the content without having that "blank" page. How can I achieve this?
At first thought, I think you could you the same approach as infinite-scroll, which is what I'm using. So you make a GET request to the server to get new content and push it to the list on clicking 'next'. However, since the URL changes also. This will cause the controller to be reloaded. You can actually bypass this by setting reloadOnSearch to false.
i'm working with angular js now for about ke 4 months and despite all the "first step failures" like not emphasising the async way anuglar thinks, I'm facing a problem I don't really understand. It's not that easy to describe.
I have a provider which registrates directives within the routeprovider's resolve function - during config phase. To compile programmatically preconfigured directives I create them on the specific controller call of each route. Acutally the directive I'm adressing here is a complex flotchart directive. It retrieves data from a rest api, transformes the retrieved data and prepares different kinds of option setups like proper stacked line charts or simple piecharts. Every single step takes its time, so I introduced promises to be sure that everthing is at it's right place before I finally call something like "$.plot".
So now I have the following situation: Imagine a singlepage app with two tabs. Each tab - like a first class menu item - refers to a new page with a new controller to process and new partials to render. For each page i have beside other directives one of these heavy flotchart directives to render. actually it takes about 5 seconds to render the chart. So we assume that we really start the app from beginning - like pressing F5. Now I enter the first page the first time and within the mentioned 5 seconds I switch tabs to enter the next page. I get to the next page, see different partials, layouts and stuff and a loading chart - but actually the directive of the first page is still bound to its link phase of that heavy flotchart directive (still preparing options for flot and calculating data to output graphically).
My problem is that this link phase actually really ends within a completely different template/route/controller context and gets stuck. It crashes with a console "replace" error from jquery.flot. I think this error means that flot tries to plot into a div which does not exist anymore. But that error occures just when I switch tabs during the link phase of the first page's heavy flot directive. It doesn't happen when the first page's chart is fully rendered and doesn't happen when the first page's directive hasn't entered its link phase (or am i missing something??). I tried placing some console.logs directly BEFORE hitting the jquery "$.plot" - remember only of the first page chart directive to dive into what's acutally happening. And the strange thing is when I manage to switch tabs within these magic 5 seconds, I still get the console log entries from the first page entry although I'm on a different page. And now guess what. That's strange - acutally two directive link phases are running side by side and one of them on a completely different view (or isn't it completely different, because its a singel page app?). Imagine I plot ("render") the chart in exactly the same div id - like $('#flot-chart'). so I have html parts containing id="flot-chart" on the first page AND on the second. when I now switch from the first to the second page (not finishing the first chart) I get the chart from the first page rendered in the #flot-chart div of the second page and like half a second later the actually correct chart rendered in that same div. So actually the link phase of the first page's chart directive ends in a completely different page in a way showing 2 charts consecutively. I know jquery.flot depends on DOM manipulation via jquery and that might be the problem (perhaps THAT'S the only real explanation for my problem), because jquery DOM manipulation is out from the angular way of life.
Or are there other explanations? I acutally solved the problem via $routeChangeStart listening and killing the $.plot process, but are there some hints, suggestions, explanations for that behaviour?
Plunker flot chart directive DOM collision
I have prepared a plunker which shows kind of a similar behaviour. i've delayed the creation of the directive and the directive's async data and option retrieval methods to somehow mock the behaviour of my app. this is non production code but describes simplified the way my problems occure. when you "fast click" the menu item one after the other many times, you can sometimes force angular to show 2 charts in one page. acutally one directive is linking and doing stuff in a different partial ? i know i'm missing something in my mind ... please give me a hint.
i used chrome for reproducing the error. stop the the plunker and press 'run'. directly after pressing 'run' click as fast as you can both links a couple of times.
Thanks a lot!