Semantics of validation from path has changed

[dairiki]

In Cornice < 2, when a schema item had location=path, it was extracted/validated from request.matchdict. This allowed for code like

class MySchema(colander.Schema):
    item_id = colander.SchemaNode(
        colander.Integer(),
        location='path')

@resource(
    path='/items/{item_id}.json',
    schema=MySchema)
class ItemResource(object):
    def __init__(self, request):
        self.request = request

    def get(self):
        item_id = request.validated['item_id']
        return {'id': item_id}

In Cornice >= 2, I would naively translate the above to

class PathSchema(colander.Schema):
    item_id = colander.SchemaNode(colander.Integer())

class MySchema(colander.Schema):
    path = PathSchema()

@resource(
    path='/items/{item_id}.json',
    schema=MySchema,
    validators=(colander_validator,))
class ItemResource(object):
    def __init__(self, request):
        self.request = request

    def get(self):
        item_id = request.validated['path']['item_id']
        return {'id': item_id}

This does not, however, seem to work. Currently, extract_cstruct puts request.path (a string) into cstruct['path'] (and does not appear to make request.matchdict available at all.)

I would suggest that extract_cstruct should be modified to make request.matchdict available in the cstruct; either as cstruct['path'] (replacing request.path) or as cstruct['matchdict'].

Am I missing something?

[leplatrem]

Your feedback seems totally valid!

In Cornice 1.2, we used request.matchdict
https://github.com/Cornices/cornice/blob/1.2.1/cornice/util.py#L187

I'm open to both approaches: request['path'] as before, or in a new key 'matchdict'. The first one would just be a simple bug fix, the other one is a new feature with the required details in the upgrading docs.

Would you be willing to open a pull-request with the small fix please?

[dairiki]

Yes, I can come up with a pull request.

(Upon further consideration, I think my first approach is the right one. Otherwise the semantics of 'path' change for error reporting as well.)

[Natim]

However I thought the change for the error reporting part was done on purpose.