Do not type newline when enter pressed in textarea in EmberJS

I need to submit changes when the Enter key is pressed, rather than typing a newline symbol. I'm using Ember.js and slightly customized TextArea helper.

Here is what I have in my template

{{edit-item placeholder="Weight" value=weight insert-newline="acceptChanges" focus-out="acceptChanges"}}

in my helper

App.EditItemView = Em.TextArea.extend

  didInsertElement: ->
    this.$().focus()
    this.$().blur()

  focusIn: ->
    $this = this.$()
    $this.get(0).select()
    # fix webkit select problems
    mouseUpHandler = ->
        $this.off("mouseup", mouseUpHandler)
        return false
    $this.mouseup(mouseUpHandler)

  attributeBindings: ['style', 'placeholder']

Em.Handlebars.helper 'edit-item', App.EditItemView

and in my acceptChagnges action

# In controller action hook up 
acceptChanges: ->
  $(document.activeElement).blur()
  @get('model').save()

The real problem is that when text selected and user types enter key to accept, it also types a newline which replaces all content in textarea, hence the only newline gets accepted.

How to prevent typing new line, but fire an event to accept changes?