Comments on: Knockout.JS: AsDictionary

By: Knockout.JS: Dictionary/Index and ObservableArray, Part 2 - WiredPrairie

Knockout.JS: Dictionary/Index and ObservableArray, Part 2 - WiredPrairie — Sat, 10 Mar 2012 15:51:03 +0000

[…] Ryan suggested an alternative in a comment (and corresponding jsFiddle) to the technique that I’d used in my previous Knockout.JS post. […]

By: Aaron

Aaron — Sat, 10 Mar 2012 14:51:53 +0000

I’d pondered adding the index to the original array and couldn’t decide which way I really liked it. Thanks for pointing out an alternative and providing the code.

By: Ryan Niemeyer

Ryan Niemeyer — Sat, 10 Mar 2012 03:46:50 +0000

Nice. One thing that I like to do in this type of situation is to define the computed observable as a sub-observable of the original (the observableArray is a function and can have its own properties/methods). This works well to keep the view model tidy (as this is created as more of a utility than as part of the view model), but it also is nice when you need to convert it back into JSON as ko.toJSON will naturally drop any sub-observables when it unwraps the main observable.

It would be something like this: http://jsfiddle.net/rniemeyer/T6nPP/ or the index can be kept private and a “findByKey” function could be exposed to retrieve the value like: http://jsfiddle.net/rniemeyer/T6nPP/2/