Ember.TextArea set input through handlebars helper - binding

Question

I got a Ember.Handlerbars.JSON helper, which formats a given value to an indented JSON string.
I'd like to set the content (value) of a textarea like this:
{{#view Ember.TextArea}}
{{JSON someValue}}
{{/view}}
This does not work, since what I should set the textareas' "value" attribute instead.
However, this also doe not work
{{view Ember.TextArea valueBinding="JSON someValue"}}

Answer 1

You could solve this by using a computed property, see http://jsfiddle.net/pangratz666/3A33H/:
Handlebars:
<script type="text/x-handlebars" >
{{#with App.jsonController}}
{{view Ember.TextArea valueBinding="formatted" rows="10" }}
{{/with}}
</script>​
JavaScript:
App = Ember.Application.create({
formatJSON: function(obj) {
return JSON.stringify(obj, null, '\t');
}
});
App.jsonController = Ember.Object.create({
content: {
abc: 123,
foo: 'hello'
},
formatted: function() {
var obj = this.get('content');
return App.formatJSON(obj);
}.property('content')
});​
Update to your comments:
In the fiddle in the comment ( http://jsfiddle.net/4QNur/ ) your are declaring {{view Ember.TextArea valueBinding="JSON App.someComplexValue"}}: this does not work since valueBinding takes a path as argument and not an expression, like JSON App.someComplexValue. If you want to bind to a transformed value, just create a computed property and bind to this. That's the Ember way of doing such stuff...
In your original question you have the following code:
{{#view Ember.TextArea}}
{{JSON someValue}}
{{/view}}
This does not work in this case, since the value for the Ember.TextArea can only be set via a value respectively valueBinding:
{{view Ember.TextArea valueBinding="App.controller.transformedComplexValue" }}