feat: improve support for minItems and maxItems for array layout and control

[Typiqally]

Added improved support for the minItems and maxItems properties, to allow for more fine-grained control and validation in ArrayControl and ArrayLayout applications. I have also added additional tests to cover these properties.

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While working on this, I realized that the current handling of array (or items) schemas is too restrictive for custom implementations. Specifically, the schema is being completely replaced by the items schema, which typically only includes a basic type description and hides important details like the min and max item properties from the original array schema.

jsonforms/packages/core/src/mappers/renderer.ts

Lines 798 to 818 in fcef896

	export const mapStateToArrayControlProps = (
	state: JsonFormsState,
	ownProps: OwnPropsOfControl
	): StatePropsOfArrayControl => {
	const { path, schema, uischema, label, ...props } =
	mapStateToControlWithDetailProps(state, ownProps);
	const resolvedSchema = Resolve.schema(schema, 'items', props.rootSchema);
	const childErrors = getSubErrorsAt(path, resolvedSchema)(state);
	return {
	...props,
	label,
	path,
	uischema,
	schema: resolvedSchema,
	childErrors,
	renderers: ownProps.renderers || getRenderers(state),
	cells: ownProps.cells || getCells(state),
	};
	};

To address these limitations, I see two possible approaches:

1. Add a parentSchema property to preserve the original schema, keeping the existing behavior while easing the constraints. This might introduce some confusion around naming.
2. Store the original schema in the schema property and put the resolved schema in a new arraySchema or itemsSchema property. However, this would change the current behavior, requiring migration.

I’d appreciate your thoughts on these options.

[CLAassistant]

All committers have signed the CLA.

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[sdirix]

I agree that the current situation is not optimal. I would like to suggest to add a new prop arraySchema in which the schema referring to the array is handed over. For now we should not adapt the schema prop, as this will certainly lead to backward compatibility issues with custom renderers.

We could think of a migration path with a major release or just keep the current prop naming, even if it's not ideal.

@Typiqally can you add this arraySchema prop?

[Typiqally]

I have added the arraySchema prop.

The minItems and maxItems props have become redundant because they can now be accessed via the arraySchema prop. I propose reverting the previous changes related to these props and deprecating the existing minItems prop in ArrayLayout to warn future custom implementations about depending on this prop.

What do you think @sdirix?

[sdirix]

Yes, let's refactor our code so we use arraySchema where appropriate. If a binding did hand over minItems then we should still do that to not break anyone on the update.

[Typiqally]

@sdirix, I have removed the props and deprecated the original minItems property in favour of using arraySchema.minItems. I don't see an usage of this property anywhere in the internal packages. Only the Vuetify package seems to be using something related to minItems, but they get around these props by resolving the schema manually in the component itself.

[sdirix]

Thanks ❤️