Rendering views based on dynamic content in Ember.js Handlebars? - ember.js

Question

Is it possible to dynamically render content in ember directly from the template?
i.e., using 4 links that are bound to 4 different template names:
v1
v2
v3
v4
{{render view.view_to_render generic_controller}}
or are there more efficient ways to achieve this?

Answer 1

From the original post, I guess that you would like to render dynamically an actual view, rather than a partial template.
The snippet
{{render view.view_to_render generic_controller}}
does not work (in my experience), because ember tries to look for a view named 'view.view_to_render', rather than interpreting it as a variable to read the view from.
The solution I use is to have a custom helper:
Ember.Handlebars.registerBoundHelper( 'renderBoundView', function ( panel ) {
var args = Array.prototype.slice.call(arguments, 1)
Array.prototype.splice.call(args, 0,0,panel.view, 'panel.model')
// Call the render helper
return Ember.Handlebars.helpers.render.apply(this, args)
})
This helper extracts the view name from the variable 'view' in the passed object, and then passes that name to the standard render helper. Then using
{{renderBoundView panel}}
where panel has properties 'view' with the name of the view and 'model' containing the (resolved) model does the trick.
Of course you could also interpret the object passed as a variable name to get from the current context (which is also one of the arguments passed to the helper).

Answer 2

The entire purpose of Ember is to dynamically render content.
If you want to render particular "views" that are driven from data, that's pretty easy in Ember. Ember calls these partial templates "partials", appropriately-enough :)
Say you have an attribute called partialToRender set in your controller for the template that you're doing your "generic rendering" on. Say it's bound to a set of buttons which are bound to actions which each change the value of partialToRender. Something like this:
<button {{action changePartialToRender 'hello'}}>Change to Hello</button>
<button {{action changePartialToRender 'goodbye'}}>Change to Goodbye</button>
<button {{action changePartialToRender 'yes'}}>Change to Yes</button>
<button {{action changePartialToRender 'no'}}>Change to No</button>
and then in your controller you'd have an action something like this:
App.IndexController = Em.ObjectController.extend({
partialToRender: null,
actions: [
changePartialToRender: function(newValue) {
this.set('partialToRender', newValue);
}
]
});
That'd mean whenever the user clicked on one of your buttons, the value of partialToRender would be changing. Sweet, right? :)
So now all that we need to do is hook up our bit of template code that renders the partial. A partial is just another template, but it's part of a page rather than a full one... some bit of different content in each case, to render into our initial template...
So, we revisit the template like this:
<button {{action changePartialToRender 'hello'}}>Change to Hello</button>
<button {{action changePartialToRender 'goodbye'}}>Change to Goodbye</button>
<button {{action changePartialToRender 'yes'}}>Change to Yes</button>
<button {{action changePartialToRender 'no'}}>Change to No</button>
{{#if partialToRender}}
{{partial partialToRender}}
{{/if}}
Note I'm just wrapping the partial in an if statement to make sure it doesn't render if it's not set.
Also note that I haven't specified the partials here for you. I've just kind of whet your appetite. If you're really interested in this, I suggest watching the Ember video on the getting started guide in the ember site. It's a bit rambling, but it shows off some of Ember's powerful features, or possibly go through the guides / tutorial over at the Ember main site.
Hope that answers your question :)