`request.post_vars()` cannot handle multiple values for a key

Lines 138 to 140 in 832f76c

    
           async def post_vars(self): 
        
               body = await self.post_body() 
        
               return dict(parse_qsl(body.decode("utf-8"), keep_blank_values=True))

Datasette GET requests often use ?_facet=category&_facet=size - but right now there's no neat way to handle that with POST data, since this code reduces any multiple values to just one.

This came up while working with <select multiple> (enhanced using Choices.js) in:

datasette/datasette-acl#24

Fixing this may be as simple as returning a MultiParams instead:

datasette/datasette/utils/asgi.py

Lines 120 to 122 in 832f76c

    
           @property 
        
           def args(self): 
        
               return MultiParams(parse_qs(qs=self.query_string, keep_blank_values=True))

That should behave like a regular dictionary so it's possible it won't break existing plugins?

	async def post_vars(self):
	body = await self.post_body()
	return dict(parse_qsl(body.decode("utf-8"), keep_blank_values=True))

	@property
	def args(self):
	return MultiParams(parse_qs(qs=self.query_string, keep_blank_values=True))