RFC Shift schema PHP api out of LeftAndMain

[tractorcow]

Introduction

At the moment the php form schema API is hard-coded into LeftAndMain with the following endpoints:

• methodSchema()
• schema()
• getFormSchema()
• setFormSchema()
• getSchemaResponse()

Recommendation

Instead, I suggest to shift this into LeftAndMainFormRequestHandler. The schema method would be moved into this request handler as a default allowed_action.

Rationale

Primarily this would flatten and simplify the role of LeftAndMain.

The other aim is to eliminate unnecessary complexity required in routing schema urls. For instance, we need separate schema / methodSchema to resolve the schema action for any forms, and potentially more methods would need to be added for different form URLS.

Shifting this into a schema action on the request handler would automatically provide a schema route for any pre-existing form route.

For instance, the schema url

/admin/methodSchema/Modals/remoteCreateForm

would become:

/admin/Modals/remoteCreateForm/schema

[flamerohr]

Also include moving FormField schema specific logic, we can achieve this with the use of extensions and schema data could be handled by generators.

@tractorcow described it to me much more succinctly than I can put into words.

[robbieaverill]

Would make #240 obsolete

[flamerohr]

Yes, the whole idea of moving all the schema out is so we could pull it out of framework entirely when it's not needed (e.g. we built a new admin which doesn't use the schema, or a framework only install)

[tractorcow]

Details I discussed with @flamerohr:

• formfields dont manipulate schema anymore. There's a generator class (injected by extension) that does that
• yaml can inject specific subclasses of generator for specific field types
• shift LeftAndMainFormRequestHandler to this module. Make the name something smarter. Like SchemaFormRequestHandler.
• admin module requires this new module

[flamerohr]

I think LeftAndMainFormRequestHandler is very handy in itself (field actions), and it doesn't need to be coupled with schema logic.

But SchemaFormRequestHandler could be extending it!

[tractorcow]

All LeftAndMainFormRequestHandler does is add another URL segment. that could be moved to core FormRequestHandler though.

[flamerohr]

True, good point