Uncaught TypeError: Property 'reevaluationBroadcast' of object #<Object> is not a function

[macduy]

Hi

I ocassionally get the following error when I run a ko.atomically(...) block:

Uncaught TypeError: Property 'reevaluationBroadcast' of object # is not a function

Not sure how useful it will be for you but here is my stack trace:

evaluate                                beickhoff.knockout-1.2.1.js:1247
ko.dependentObservable                  beickhoff.knockout-1.2.1.js:1277
DisplayableFData.Class.initialize       fchart.js:193
b.i.extend.$owner                       mootools-core-1.3.2.js:76
a.Class.Type.g.$constructor             mootools-core-1.3.2.js:71
FChart.Class.addDataset                 fchart.js:400
b.i.extend.$owner                       mootools-core-1.3.2.js:76
bindings.addDataset                     test.js:50
ko.atomically                           beickhoff.knockout-1.2.1.js:995
bindings.addDataset                     test.js:49
ko.bindingHandlers.init                 beickhoff.knockout-1.2.1.js:1635
f.event.handle                          jquery.min.js:17
f.event.add.k.i.handle.k                jquery.min.js:16

Maybe collision with Mootools?

[beickhoff]

The problem occurs when you try to create a new dependentObservable inside of a callback to ko.atomically. I'm not sure if that's a good idea. Do you have a use case for this? Regardless, the current behavior should be improved. I need to go back to my design and reconsider the implications of extending the graph during an atomic update.

In setUpWritePhase I (temporarily) remove the reevaluationBroadcast function. Ordinarily, that function shouldn't be invoked because we are preventing reevaluation. However, if you create a new dependentObservable, it may automatically evalute once. That's what causes the exception you were seeing.

[beickhoff]

After some brief consideration, I think creating dependentObservables in a ko.atomically callback should be safe. The callback is executed during the mutation phase, so this shouldn't pose any problems. Purely out of curiosity, I'd still like to hear if you have a use case for this.

[beickhoff]

I just realized this is the wrong repository for this issue. Can you reopen this issue in https://github.com/beickhoff/knockout?

[macduy]

I'm happy to discuss and give insight into my code once you open the issue tracker ;)

[macduy]

In regards to this one, let me describe the whole picture: I'm making charts capable of displaying several data series. Each series is represented as data, from which a range is computed. Range is thus an observable on the data. This range is then used to compute a global range over all data series, also a dependent observable.

Now, whenever I add a new data series (and thus create a dependentObservable - the range), I enclose it in an atomic update block.

[beickhoff]

This should be fixed in the latest build. Try it out and let me know if it works for you.