knockout.validation module has stopped working in 3.5.0-rc

[azaslonov]

Hi guys, knockout validation module has stopped working in 3.5.0-rc, saying this:

knockout-latest.js:84 Uncaught Error: ko.applyBindings: first parameter should be your view model; second parameter should be a DOM node
    at a.qc (knockout-latest.js:84)
    at Object.ko.applyBindings (knockout.validation.js:1472)
    at HTMLDocument.<anonymous> (startup.designtime.ts:50)

Simple repro: https://jsfiddle.net/azaslonov/4z62mw1r/

Considering they didn't release since 2015, there is probably something got broken in KO itself.
https://github.com/Knockout-Contrib/Knockout-Validation/releases

Can you guys please have a look?

[fastfasterfastest]

See https://github.com/knockout/knockout/issues/2388 - to summarize, prior to 3.5 it was unspecified what it meant by passing a non-DOM-node value as a 2nd parameter to ko.applyBindings; in 3.5 if you pass a 2nd parameter it needs to be a DOM node.

Knockout Validation overrides ko.applyBindings and always passes a 2nd parameter to the original ko.applyBindings. In your sample, knockout therefore throws an error because the value of the parameter that gets passed to the original ko.applyBindings is undefined, which is not a DOM node.

Probably, the easiest way if you use Knockout Validation is to always passing a 2nd parameter explicitly with the value document.body. In your sample, change ko.applyBindings() to ko.applyBindings(undefined, document.body)

[azaslonov]

Thank you, I think I can live with this for now.

[fastfasterfastest]

Alternatively, patch knockout-validation and change the call origApplyBindings(viewModel, rootNode) to origApplyBindings.apply(this, arguments).
If you are using its ko.applyBindingsWithValidation you probably need to update it as well.