Why is it it necessary to always create views and controllers?
Isn't it possible to say: each view that does not have a specific controller class, falls back to using the applicationController instance, when is being attached as an outlet.
Possible?
The connectOutlet method has a controller option you can pass:
postsController.connectOutlet('createPost', { controller: 'application' })
That said, we are in the process of improving the router API in general to put a greater focus on templates and making the View class optional (you'll only need one if you have events to handle).
Related
I have inherited a codebase and trying to make sense of what is what. In emberjs application how do I know which controller (js) corresponds to a view (hbs) on a particular page. Is there a setting? Is there a convention?
The convention is that their names (or more accurately their paths) should be the same.
As in, controllers/page.js should have a templates/page.hbs and a routes/page.js
You can see this convention if you create a new Ember project using ember new or ember twiddle.
You can also specify the template name within a route using the templateName property.
// routes/page.js
import Route from '#ember/routing/route';
export default Route.extend({
templateName: 'something/different'
});
Ember also allows us to use the renderTemplate hook within our routes and pick a different template and/or a different controller.
// routes/page.js
export default Route.extend({
renderTemplate(controller, model) {
// Render the `something/else` template
// and use the and `other/thing` controller
this.render('something/else', {
controller: this.controllerFor('other/thing')
});
}
});
Read more in "Ember JS Guides: Rendering a template"
Ember also used to allow embedding templates within other templates using the partial helper.
It would matter a lot which Ember version you are using because that would restrict your concerns to a certain API behavior, since Ember did change a lot through the years.
For the most part it's pretty simple. Ember follows convention over configuration so let's learn the convention. The algorithm is as follows.
Look at the current url that you are on. In this case, we are on /foo
Open up the router.js file and find the route that matches this url pattern. If you don't specify paths then the url will just be the name of the route, but you could also be dealing with nested routes. Let's say we found route named foo.js which would be under appName/routes/foo.js.
Open the route file. Routes jobs are to fetch data in the model hooks, and then to set the variables on the corresponding controller instance via the setupController(controller, model) hook. When not specified, this method just sets the entire model object on the controller. Now we should have a decent idea of what variables have been dynamically set on the controller.
Open the controller under appName/controllers/foo.js. The best way to think about controllers is they are the single source of state for the corresponding template (appName/templates/foo.hbs). Their values are set via hooks on the route, as well as through the init method, computed properties, observers, etc. When you reference any {{variable}} in a handlebars template, the controller that matches this portion of the page's context is the source of state that resolves this variable. If the controller isn't defined, then Ember autogenerates one for you. Worth noting that controllers are singletons and their state persists between route changes.
Open the template.hbs file to see your markup. You might have components (custom html-looking tags that take attrs) which store their javascript under appName/components/component-name.js and their templates in appName/templates/components/component-name.hbs or have no template if the javascript file can just specify a tagName and that's it.
One other quick thing: routes are invoked in a parent/child hierarchy and correspond to urls via the route. The top level route is the application route. If you look in it's template, you will find an {{outlet}} Ember will then find whatever child route comes next and render its template into this outlet. by default /, the index route's template is rendered. But if the url was /foo then foo.hbs will be rendered into the application's outlet. Foo.hbs can have an outlet, and thats when we start getting into nested routes. That's about as quick/high level overview as I can give, ask any questions if you want specifics (I love Ember)
I Have an Angular app, that currently uses $routeProvider to map a route to a controller and template.
Some of the routes render collections of items, and at the moment it simply includes another template for each item, accessing the controller of the parent template.
main route template...
<div ng-repeat="item in vm.collection">
<div ng-include="'/views/item.html'"></div>
</div>
However, as this app is growing, it feels like the include, the item view, should have its own controller, separate to the collection controller, allowing it be reused more easily throughout the app.
What is the best way to approach this?
If you have functionality that can be thought of as a Component, you should use Services (if it doesn't have a UI) or directives (if it does have a UI).
If the functionality you wan't to separate is not that generic to implement as a reusable component, you could create a Controller and use it with the ng-controller directive.
Another way to use the controller is to switch to UI-Router, which allows nested views.
Please take a look at this JSBin1. I am using the same template for both the render in the index template and manually rendered in the renderTemplate function of the ColorsRoute. Clicking the More Colors link does not render the list of colors I return in the ColorsRoute model hook. Now, if you change the render 'colors-list model to render colors-list2 model, as I have done here, everything works as I would expect it to. The only difference between the two is that in JSBin1, I am only using the colors-list template, but in the second working example, I have one template for the render and an identical, differently named template for the ColorsRoute.
The code example, while trivial in the JSBin, is an exact extraction of something I am doing in a much larger application. This application has a bunch of widgets, which I represent by multiple named outlets in the same templates. I manually render into these outlets, as I do in the JSBin in the ColorsRoute renderTemplate hook. I do the manually rendering so that when certain events happen, I have actions defined on the route that will allow me to dynamically replace the contents of the outlet after making an ajax call to a REST API.
What is the explanation for this kind of behavior?
It's more related to the controller that's being created, not the template. And technically I'd say it shouldn't work on either, but it appears there's some route where if you don't define a controller, and that type of controller hasn't been created, create it, and use the current controller/model as the model backing it.
Really you should be providing a controller when using render if you're expecting it to have that controller as the backing controller.
renderTemplate: function(controller, model){
this.render();
this.render('color-list', {
outlet: "named",
into: 'colors',
controller: controller
});
}
http://emberjs.jsbin.com/cevagocekofu/3/edit
There are scattered explainations of each around, but I'm still not 100% clear on the differences & usage. Could someone give me a side-by-side comparison?
{{outlet}}
{{outlet NAME}}
{{render}}
{{partial}}
{{view}}
{{control}}
Note: this post was very helpful with partial vs render
They are all template helpers with the following main characteristics as described in emberjs guides.
(http://emberjs.com/guides/templates/rendering-with-helpers/)
1.{{outlet}} - Renders a template based on the route determined by the router. Based on the route the corresponding controller and view are used. This is useful when rendering contents based on the route, which is the most common case.
2.{{outlet NAME}} - Provides the ability to specify in the route where exactly to render the content. Useful when trying to render contents from more than one templates for a route.
3.{{render}} - Similar to outlet but the controller/view/model can be specified directly or indirectly from the helper. Useful when required to render content from more than one template with the ability to override the context (view/controller) and model. If model is specified it uses a unique instance of the corresponding controller, otherwise it will use the singleton instance. Useful when required to overide the route's context and model, while rendering multiple template contents.
4.{{control}} - Works like render, except it uses a new controller instance for every call, instead of reusing the singleton controller. When using render it is not possible to use multiple render for the same route without specifying the model, for that case the control should be used. Useful to support new instances of a controller for every template content rendered.
Update: Control helper has been removed https://github.com/emberjs/ember.js/commit/86eecd7ef7cdc7d2ea6f77b3a726b293292ec55d .
5.{{partial}} - Takes the template to be rendered as an argument, and renders that template in place. It does not change context or scope. It simply drops the given template into place with the current scope. So no view class is specified for the partial. Useful when it is required to break a template into template modules, for better control or reusability, without creating any view classes.
6.{{view}} - This works like partial but a view class is provided. The view class specifies the template to be used. Useful when breaking a template into modules but requiring a view class e.g. for event handling.
7.{{#view}} - There is also the block form of the view helper, which allows specifying the template of the child view inline with the parent view template. (http://emberjs.com/guides/views/inserting-views-in-templates/)
{{outlet}} this defines where nested resources/routes will be rendered inside a route's template
{{outlet NAME}} this creates a named outlet where you can programmatically render something into
App.PostRoute = App.Route.extend({
renderTemplate: function() {
this.render('favoritePost', { // the template to render
into: 'posts', // the route to render into
outlet: 'posts', // the name of the outlet in the route's template
controller: 'blogPost' // the controller to use for the template
});
this.render('comments', {
into: 'favoritePost',
outlet: 'comment',
controller: 'blogPost'
});
}
});
{{render}} takes two parameters:
The first parameter describes the context to be setup
The optional second parameter is a model, which will be passed to the controller if provided
{{render}} does several things:
When no model is provided it gets the singleton instance of the corresponding controller
When a model is provided it gets a unique instance of the corresponding controller
Renders the named template using this controller
Sets the model of the corresponding controller
{{partial}} takes the template to be rendered as an argument, and renders that template in place (using the current scope as the context).
{{view}} This helper works like the partial helper, except instead of providing a template to be rendered within the current template, you provide a view class. The view controls what template is rendered.
{{control}} is deprecated works like render, except it uses a new controller instance for every call, instead of reusing the singleton controller.
Most of this I just copied and pasted from their documentation: http://emberjs.com/guides/templates/rendering-with-helpers/
render helper is deprecated in v2.x instead you need to use ember-elsewhere addon. https://emberjs.com/deprecations/v2.x/#toc_rendering-into-a-render-helper-that-resolves-to-an-outlet
ember.view is deprecated in v1.x instead use Component. refer https://emberjs.com/deprecations/v1.x/#toc_ember-view
control helper is experimental only, its already removed
I would say currently only {{outlet}} is encouraged one remaining all are either deprecated/removed.
Main differences are
{{view}} renders the provided view class which should be available
{{partial}} renders the template available in Ember.TEMPLATES. its may not have related the view class. Advantage is context of the template remains of the parent view.
{{outlet}} Specify the router that here it is supposed to render the provided view or template or as per renderTemplate() hook.
{{outlet NAME}} useful when you want to render two views/templates at different positions. You can name the outlets and ask router to render.
{{render}} same as outlet except you force the router to render specific view/template.
I have a router with corresponding templates for each route (and route objects). I want to be able to display each template independently of its parent, meaning I don't want the nested routes to be rendered to the parent template's outlet. Essentially making a separate "page" for each nested route.
App.Router.map(function() {
this.resource('recipes', function() {
this.route('new');
this.route('show', { path: '/:recipe_id' });
});
});
I'm using ember1.0.0-rc1
Thanks
I want to be able to display each template independently of its parent, meaning I don't want the nested routes to be rendered to the parent template's outlet.
Maybe stating the obvious but that's exactly what will happen if you don't create a template for the resource. In your case, if you don't create a recipes.hbs template then ember will render the new.hbs and show.hbs templates into the {{outlet}} in application.hbs.
NOTE: If you do this, Ember will output a console warning "The immediate parent route did not render into the main outlet ..."
This is explained in more detail in the ember routing guide
Quick note from the ember guides
If you define a resource using this.resource and do not supply a function, then the implicit resource.index route is not created. In that case, /resource will only use the ResourceRoute, ResourceController, and resource template.
Your routing is fine and #mikegrassotti is correct, although if you want an index for "recipes" without having your "new" and "show" route templates nested inside "recipes"(no master/detail) you will need to create an recipes/index template with no outlet inside.
<script type="text/x-handlebars" data-template-name="recipes/index">
<ul>
{{#each}}
<li>{{recipe}}</li>
{{/each}}
</ul>
You do not need to change your route setup. As Mike mentioned above ember will render the new.hbs and show.hbs templates into the {{outlet}} in application.hbs
Ember.js does not support nesting routes, it only supports nesting resources. The ultimately-nested route can contain a route.
Think of resources as things, and routes as actions.