Adding the view to dom id main-wrapper one router calls the view.Page loads one by one because of the sub view added in within main-wrapper. Need to know something similar to smooth loading the dom with fade in effect or shows the page once the dom is loaded.
Another approach you can take is hold off on adding the view to the main-wrapper until all subviews are created. Create a document fragment (default behavior if "el" is not defined). Once your view and its descendent views are all created in document fragment, then add it to the main-wrapper div. This way all of your content are shown at the same time instead of one view at a time.
Either use jQuery's onReady event or the native window.onload event. In both cases you register a callback function that then kicks of the initialization of the respective Backbone views.
Related
I'm re-working a website that has a very nested interface requiring several child views. Think of a shopping site, with paging, results and filters. What I'd like to do is render default content for said children views while the results are being resolved from the back-end. However, I can't find a way to insert default content past the first <ui-view>, which of course, makes sense.
To get around this, we are currently using $broadcast in the child state controllers. We moved the resolution out of the resolve event into the controller, which is working, but requires us to make all of our directives use $broadcast as well, or they don't work since the data isn't loaded before they are. It also seems like a very inelegant solution to the issue.
What's weird, is that when I move the resolve function into a child view, neither the parent nor it's siblings views load before the results child view loads. I can't understand that whereas I can understand children views not loading before the parent is resolved.
Is there a way we can work around this? Building in broadcasting into all aspects of our code base seems like an extremely poor practice. Is there a way to show children default content before the parent is resolved, or even render child states' views before their controllers are instantiated?
Use ng-cloak class:
https://docs.angularjs.org/api/ng/directive/ngCloak
The ngCloak directive is used to prevent the Angular html template from being briefly displayed by the browser in its raw (uncompiled) form while your application is loading. Use this directive to avoid the undesirable flicker effect caused by the html template display.
What is the best way to switch to a different view when user navigates to a different url. In angular there is ng-view that takes care of this and inserts corresponding templates and in ember its all route based.
Is it better to just hide other views elements on routing using css or destroying other views and inserting current view?
EDIT
It would be great if someone could give an example how to re-render the view on navigating back to it again and restoring its previous state.
Eg.
if you have a check-box in a view that user can select to add some item to the cart , but in the middle he/she moves to some other url and then comes back, that check-box should be checked.
I would have a main content view with subviews and call remove on it, which is responsible for cleaning up any subviews too (calling remove on them first and going up the hierarchy tree). The concept of subviews doesn't come for free with backbone but isn't hard to implement. And finally attach a new content view.
This ensures you can cleanup and the browser is using a consistent amount of resources.
I would abstract this into some kind of layout view which has a content subview and a function like setContent(view) which handles the remove of any existing content view and the attach of the new one.
Personally I would have a router with sub routers in modules, e.g. a main router which finds a route starting with "checkout" and passes it over to a sub router in the checkout module which is responsible for attaching a new content view.
In Backbone the implementation is up to you which is both good and bad, depending on how nice you do it ;)
Always remove the view as opposed to just hiding it. If you don't remove (and unbind) your views properly, all bindings, handlers and references to models/DOM elements will linger around.
Depending on the size of your app, you can have a module that handles layouts (as suggested by dominic-tobias), or have a method on the router that takes care of this for you. At its most basic, this method (let's call it _switchView) takes a view and holds onto an instance of the currentView. Upon view change, it removes the current view, sets the new view to the current view and then renders it to the DOM.
Something like this:
_switchView(view) {
this.currentView && this.currentView.remove();
this.currentView = view;
this.$rootEl.html(view.render().$el);
}
I have a view where i have 3 links(routers which have methods triggering a View bound event).
Normally based on the link i click i reduce from the main collection a subset and render it in another VIEW.
But suppose i have clicked on a link say '....#/remaining' and then i click again on the same link, the event bound is not triggered.
But when i click on any other link and click back on the desired link, everything works!
Is this a Backbone feature/defect, if so what are the alternatives to work around this?
Thanks in Advance.
I think this is because you're doing the reduce in the Router. When you're already on #remaining, your route handler won't execute because there's no route change at all.
Instead of that, you could use a View UI event on the link to manipulate the collection, so it will always be called no matter if you're already on that route or not.
You could also use events as a communication method between your app's components: your data, your views, and so on.
Hope it helps, I didn't put any code because you didn't either. :)
I am using a directive "slideable" which creates a slideout area and has a toggle. This code that was not written by me but it demonstrates a larger issue for me. When I changing views (most commonly /user/:id type), slideable is a directive used on the template. The directive searches for an element during its link function and binds a click event. The issue is that when I am changing routes and the new view ( same type but different id ) is being loaded the directive is re-binding to the old view. If I stop the browser in chrome during the link then I will see two ng-views on the dom and the issue is it binds to the one that is leaving.
I also have other issues that appear to be related to this phenomenon. Is it normal that the old view would still be on the dom while the new view is being formulated?? Why wouldnt the old-view be destroyed before the new one is rendered? How do I get around this issue in a directive like this?
Thanks.
I am looking to understand conceptually what is happening. I already modified the directive to select the latest view and to appropriately search and bind to the correct element. But I am a bit perplexed as to why there would be a state where both co-exist on the dom.
One definitive reason why the old HTML fragment is briefly present along with the new one is to support animation of transitions from the old to the new. Take a look at the ngView documentation and you'll see an example of an animated transition, and it'll be clear that this is not a bug or a design flaw.
Usually when someone has problems with binding to the right element or element's event, it's because they are selecting the element without limiting the scope of the selector to the HTML fragment being added or updated, or trying to target parts of the DOM outside of the directive. So that's the first place to check, that the directive is doing things right, but like I said we'll need code to check on that.
What is the best way to let subviews/child views know when they are already in the DOM?
Consider we have following hierarchy of views:
MainView
SubView
ChildView
Here for example MainView is already in the DOM. Then as a part of render process MainView creates SubView which in turns creates ChildView.
As a result ChildView won't be in the DOM until MainView finishes its' rendering. And I need to know (via event or handler) when it is inserted and displayed.
The most straightforward answer is for MainView to trigger some event when it is done rendering. If it were the only case where I needed it - it would be alright. But there are lots of places and in general suddenly subviews dictate their parents what to do, probably not good.
Update:
In what cases this is required? When we are using widgets which expect element to be in the DOM (to get height, etc). In example: Accordion widget, jqGrid. So the correct time to init them when their container is already in the DOM.
I'm not sure what your use case is but I'm assuming its finding a DOM element within the Childview and manipulating it. In this case, it would not matter if its in the DOM or not.
What I typically do is grab the reference to the element - $el
and then find the sub-element
$target = $el.find('.target')
This has the added benefit of only allowing me to grab classes or ids within the ChildView ensuring a proper management of views.