Question

Say I have a template which displays a view based on a property:

{{#if App.contentsAreVisible}}
    {{view ToggleContents}}
{{/if}}

This area is toggled by any number of other parts of the UI by setting App.set("contentsAreVisible", [true/false]);

This all works fine.

However, I now want to animate when the view is toggled. Hooking into didInsertElement works to animate showing the area, but I can’t do the same in willDestroyElement because the element is removed as soon as that function returns, before the animation has a chance to run.

App.ToggleContents = Ember.View.extend({

    // this works fine
    didInsertElement: function(){
        this.$().hide().show("slow");
    },

    // this doesn't work
    willDestroyElement: function(){
        this.$().hide("slow", function(){
            // animation is complete, notify that the element can be removed
        });
    }
});

Is there any way to tell the view to defer removing the element from the DOM until the animation is complete?

Here’s a fiddle with an interactive example: http://jsfiddle.net/rlivsey/RxxPU/

Answer 1

You could create a hide function on your view which removes the view when the callback is finished, see http://jsfiddle.net/7EuSC/

Handlebars:

<script type="text/x-handlebars" data-template-name="tmpl" >
    <button {{action "hide" }}>hide</button>

    This is my test view which is faded in and out
</script>​

JavaScript:

Ember.View.create({
    templateName: 'tmpl',

    didInsertElement: function() {
        this.$().hide().show("slow");
    },

    _hideViewChanged: function() {
        if (this.get('hideView')) {
            this.hide();
        }
    }.observes('hideView'),

    hide: function() {
        var that = this;
        this.$().hide("slow", function() {
            that.remove();
        });
    }
}).append();​