form_example.lua

local app = lapis.Application()

app:match("/my-thing", respond_to {
	on_error = function(self)
		-- the view will have access to self.errors
		return { render = true }
	end,

	before = function(self)
		-- do everything to set up the view, since if we get an error we need to rerender
		self.the_object = TheObjects:find(self.params.id)
	end,

	GET = function(self)
		-- this function should have to do nothing, since before set it up
		return { render = true }
	end,

	POST = function(self)
		assert_csrf(self)

		assert_valid(self.params, {
			{"name", exists = true, min_length = 1, max_length = 500}
			-- .. etc
		})

		self.the_object:update({
			name = self.params.name
		})

		return { redirect_to = self:url_for(self.the_object) }
	end,
})