Initial data validation support on object create / update

[radiophysicist]

• In recourse model class method for data validation is extracted
• More error handling added in create / update request handlers
• Error message rendering added into create / update page templates

[artefom]

Looks great!

[DoubleDi]

Is there a possibility we can merge this?

[laggron42]

I added this on my end to also pass Tortoise errors on edition and not just on creation

Suggested change

	if not error:
	async with in_transaction() as conn:
	obj = (
	await model.filter(pk=pk)
	.using_db(conn)
	.select_for_update()
	.get()
	.prefetch_related(*model_resource.get_m2m_field())
	)
	await obj.update_from_dict(data).save(using_db=conn)
	for k, items in m2m_data.items():
	m2m_obj = getattr(obj, k)
	await m2m_obj.clear()
	if items:
	await m2m_obj.add(*items)
	obj = (
	await model.filter(pk=pk)
	.using_db(conn)
	.get()
	.prefetch_related(*model_resource.get_m2m_field())
	)
	if not error:
	try:
	async with in_transaction() as conn:
	obj = (
	await model.filter(pk=pk)
	.using_db(conn)
	.select_for_update()
	.get()
	.prefetch_related(*model_resource.get_m2m_field())
	)
	await obj.update_from_dict(data).save(using_db=conn)
	for k, items in m2m_data.items():
	m2m_obj = getattr(obj, k)
	await m2m_obj.clear()
	if items:
	await m2m_obj.add(*items)
	obj = (
	await model.filter(pk=pk)
	.using_db(conn)
	.get()
	.prefetch_related(*model_resource.get_m2m_field())
	)
	except BaseORMException as exc:
	error = str(exc)

[laggron42]

Hey, I tested your PR and, after solving a few conflicts, turns out great!

I copied logic from create over update to also pass validation errors to object editions.

Edit: @long2ice I have rebased and solved conflicts on this branch if you're interested in this PR, currently running in prod just fine!