[Proto-Scripty] storing a closure as the value in a Hash (and then calling it later)

[Wil]

Hi all,

I'm trying to implement a somewhat generic way for my controller
objects to listen for changes to various properties of my model
objects. I'm not a javascript expert, so there is quite possibly a
Better Way™ of solving the bigger problem - I'm open to pointers in
that direction, if my current approach is not a good idea.

Here's the machinery I currently have in place:

MyClass.prototype.observeValueChange = function(observer, property,
callback) {
    if (this.observableChanges == null) this.observableChanges = new
Hash();
    if (this.observableChanges.get(property) == null)
this.observableChanges.set(property, new Hash());
    this.observableChanges.get(property).set(observer, callback);
}

MyClass.prototype.fireValueChanged = function(property) {
    if (this.observableChanges == null) return;
    var observerInfo = this.observableChanges.get(property);
    if (observerInfo == null) return;
    observerInfo.each(function(info) {
        info.key.info.value(this));
    });
}

Here's an example of registering to listen:

objectOfMyObservableClass.observeValueChange(this, 'foo', function
(destination) {
    alert("observed change in foo");
});

objectOfMyObservableClass.fireValueChanged("foo");

Tracing through the code, everything appears fine up to the point
where I try to call the stored callback. This line:

info.key.info.value(this));

info.key and info.value are both valid objects, but nothing happens.

Thanks in advance!

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