Proposal: allow to use nullable union type not only for oneOf case

[Igor Perevozchikov]

Hi, @ebrehault!

A few monthes ago I was implemented #397 proposal to support nullable union types. And everything was good until yesterday while we not decided to move our selects to new type of widget like autocomplete and without using of oneOf property.
But constraint that I implemented in proposal doesn't allow to use this.

Another problem from my previous solution is buggy types in Schema type definition.

So in that issue I want to do the next job:

1. Remove constraint of using only with oneOf
2. Add null type as new FieldType
3. Add NullProperty, which will return null as fallback value
4. Update StringProperty to allow to return null as fallback value if property has nullable union.
5. Fix types in ISchema

[Igor Perevozchikov]

PR: #413

[Igor Perevozchikov]

@ebrehault I see that you merged PR thanks! But still have a question about npm - could you publish new version of library there with my changes?

[Eric BREHAULT]

Hi @iperevozchikov !
Yes sure, version 2.6.7 is now on npm.
By the way, for your future PRs, if you update the version number in projects/schema-form/package.json and add an entry in CHANGELOG.md, then GitHub Actions will automatically tag and publish to npm at the time the PR is merge :)

[Eric BREHAULT]

example here: 426af24

[Igor Perevozchikov]

Got it, thanks for advice!