When I use this
this.setElement($('#some-id'));
in backbone's view, what am I changing the element from? The parent DOM?
Executing new Backbone.View() shows that the default element (the wrapper for the view) is just a <div> that isn't attached to the DOM.
Not setting the el property of a view doesn't necessarily effect how your view is displayed. Ultimately, you will have to append your view to the DOM inside your render function. The el property is just a convenient way to keep track of where your view should go/is.
Related
I have a container who have inside many elements like h1, p etc.
This container have a background, and I want create method to move him by mouse coordinates. I have a problem with access to this element, because e.target show me elements inside container, not container who is binded element.
Alive any solution to share all functions between main component and child components? Because when i want get this method in anyone place now i must add :moveHero="moveHero" to every component and get this in prop array, so i want create this more globally in one place and share this to all childs. Now i think one solution for this is create .js file and import that to Vue.
You can add $ref to the container element like this: <div ref="container-ref">.
Then to access the container element in vue methods, just do this.$refs["container-ref"].
Explanation:
You can add ref attribute to any tag, even child components. It is parsed by vue only, browser ignores it.
If the ref is attached to a HTML tag, this.$refs[key] will return the corresponding DOM element.
If the ref is attached to a child component, this.$refs[key] will return the corresponding vue instance.
I'm trying to avoid wrapping with empty div when render view in backbone.
I do it with the following code
this.$el.replaceWith(this.template(this.model.attributes));
return this;
but I get empty div when I append this view by
$("#product-pannel").append(productsView.render().el);
someone give the solution like this
render: function(){
var html = this.template(this.model.toJSON()));
var newElement = $(html)
this.$el.replaceWith(newElement);
this.setElement(newElement);
return this;
}
but I can't understand why should I do this so complicatedly above
can someone tell me the mystery of el an $el?
el points to the the view element (the one that holds rest of template) and $el is a jQuery object represeting el element So that you don't have to do $(this.el) all the time.
This is clearly mentioned in the documentation.
You can either specify an existing DOM element as the view element using el option, or backbone creates a DOM element for every view. By default this will be a <div>. If you don't want an empty <div>, customize the element backbone creates as the top level element of your view template using options like tagName, attributes etc.
setElement is for dynamically changing the view element to something else... I've rarely (or never) seen it actually being used.
Say you create a new element in your View - i.e. you don't target an existing element on the page with el.
var StudentView = Backbone.View.extend({
tagName: 'article',
className: 'student-name',
template: _.template($('#name-tpl').html()),
render: function(){
var student_tpl = this.template({name: 'Rikard'});
this.$el.html(student_tpl);
}
});
You then instantiate the View and call its render method:
var student_view = new StudentView();
student_view.render();
Your HTML contains the following template:
<div class="target">
<script id="name-tpl" type="text/template">
<%= name %>
</script>
</div>
This does not print the newly created element to the page. If we set el to .target, then it would work, but then it wouldn't print your tag name or class name that you set in the View.
Is there any way to print your newly created element to the page? I thought about using jQuery append, but it seems like there should be a more backbone-oriented solution.
Unless you use the el option to attach the view to an existing element in DOM, backbone.js creates an HTMLElement in memory, detached from DOM. It's your responsibility to attach it to where you want (backbone creates a new element for you, but it doesn't know where in DOM you want it to be added).
If you already have a Backbone.View and you want to set it to a different element, you can use setElement, but in this case as well, it is your responsibility to make sure that the element is part of DOM.
If backbone gave you a way to specify the position of an element in DOM, that'd look something like:
{
tagName: 'article',
elPosition: '#container > .content+div:nth-child(3)'
}
Again, there will be confusion like whether the element should be added before elPosition, or after etc. That looks ugly, no wonder why backbone leaves it to you rather than setting up more rules. In my opinion backbone sets less rules compared to other frameworks and give you more freedom (freedom can be a pain when you don't know what to do with it :)
What we normally do is, have the main parent view point to the containing element in DOM like <body> , using the el option.
Then append the child view's to it like this.$el.appendTo(parentView.$el);
I have a custom element in Aurelia that uses a jQuery plugin under the hood (KendoUI). This custom element is being used within a view that uses the if.bind attribute.
The custom element uses an inline template, like so:
#inlineView('<template><input type="text" ref="proxy" class.bind="class"></template>')
Due to the nature of the jQuery plugin, I have to pass an element to initialize. I use the ref that I've defined in my template, like so:
$(this.proxy).doJQueryStuff(...)
After the element is detached, and then reattached, the ref element (this.proxy in my viewmodel) is null.
I initially thought that the problem was that since jQuery mutates the DOM, it was also mutating the view template. I thought that after the element is detached (and destroyed with a jQuery call to remove all KendoUI metadata), the input ref was no longer available resulting in an error upon reattachment because Aurelia was caching the view. However, this is not the case. It's been confirmed that Aurelia doesn't cache views unless you explicitly tell it to do so, and in this simplified plunk, the behavior is as expected.
Why would the reference to my ref element, in my viewmodel, be null after attaching and detaching the element?
Of note, the custom element is part of a page view, inside this construct:
<div id="application" class="au-animate" if.bind="isLoggedIn">
<nav-bar router.bind="router"></nav-bar>
<div class="page-host">
<router-view></router-view>
</div>
</div>
I don't know if anyone has run into any problems with a router-view inside of an if binding.
This issue was fixed this evening by this pull request. Run jspm update and confirm you have github:aurelia/templating-resources#0.17.3 installed.
The issue was the if template controller was not rebinding the view when re-attaching it to the DOM after it had been hidden.
I already use custom binding with knockout for displaying jqueryui dialog, but I would like to use knockout component feature.
So, I would like to write something like:
<window params="isVisible: isVisible">
//there will be some html
</window>
And later somewhere in code:
self.isVisible(true); //That would open window
//or
self.isVisible(false); //That would close window
Problem is that I don't know how to apply $(element).dialog. When I register knockout component, I can only get container element of this component, but not injected element.
ko.components.register('window', {
viewModel: {
createViewModel: function(params, componentInfo) {
// - 'params' is an object whose key/value pairs are the parameters
// passed from the component binding or custom element
// - 'componentInfo.element' is the element the component is being
// injected into. When createViewModel is called, the template has
// already been injected into this element, but isn't yet bound.
// - 'componentInfo.templateNodes' is an array containing any DOM
// nodes that have been supplied to the component. See below.
// Return the desired view model instance, e.g.:
return new MyViewModel(params);
}
},
template: ...
});
So, componentInfo.element is parent node, and if I apply dialog with $(componentInfo.element) I will set as dialog parent node, then my window tag would be:
<div><!-- Dialog will be applyed there-->
<window params="isVisible: isVisible">
//there will be some html
</window>
</div>
I think it will work, but that extra div look unneeded here... Or this is the only way to do job done?
What is knockout.components way to do this? Thanks.
I had a similar requirement when I wanted to build a Knockout component for hosting a dialog window using Bootstrap v2 'modal' functionality. I used an observable boolean value in my page's viewModel, set to false initially. There isn't a simple way to communicate with components after they have been initialized, except by passing in observables via params.
This observable was passed as a param to a <dialog-window> component in the params, e.g.
<dialog-window params="visible: showDialog">[content]</dialog-window>
This then used a special binding handler for the 'modal' dialog, but in your case you could bind it direcly using a data-bind='visible: YourParam' attribute.
The main page could then simply call showDialog(true) to make the dialog visible.
Hope this helps.