EmberJS view is not updating when updating an object in an array - ember.js

Question

I have a handlebars template where i have a table.
<script type="text/x-handlebars" data-template-name="customers">
<table>
<tbody>
{{#each nomday in allnominationdays}}
<tr class="nomdays" {{action "saveNomDay" nomday on="focusOut"}}>
<td>{{nomday.confirmedVolume}}</td>
<td>{{nomday.variance}}</td>
</tr>
{{/each}}
</tbody>
</table>
</script>
In my controller i have a function which i call from the action saveNomDay defined on the tr.
update: function()
{
console.log('Not Working');
allnominationdays = this.get('allnominationdays');
//this.set('allnominationdays',null);
allnominationdays.objectAt(0).variance = 75;
this.set('allnominationdays',allnominationdays);
},
But my view is not changing when i change the value of the object array. If i set the object array to null the template updates and shows no table. I am not sure what is breaking the binding for the view to update?
the code block updates the view when in a controller function but not when called on a action. But inside the action setting the array of object to null update the view and removes the entire table. Don't know what is going on. New in EmberJS
THanks,

Answer 1

I am too late but better late than never. This is happening because the view is getting rendered before the update in the value can propogate to the screen. Do something like the following code :
--template
{{#if isVisible}}
<table>
<tbody>
{{#each nomday in allnominationdays}}
<tr class="nomdays" {{action "saveNomDay" nomday on="focusOut"}}>
<td>{{nomday.confirmedVolume}}</td>
<td>{{nomday.variance}}</td>
</tr>
{{/each}}
</tbody>
</table>
{{/if}}
--component / controller
self.set('isVisible',false);
var propgationPromise = new Promise(function(resolve, reject) {
//update Value
console.log("promise started");
resolve();
});
propgationPromise.then(function(){
console.log("promise stopped");
self.set('isVisible', true);
});