RESTful request args/vars with JSON array

[Henry Nguyen]

I have a function in my controller decorated with the @request.restful() decorator. I would like to be able to accept a JSON array of objects, 

[{"id": 1, "new_value": 1},{"id": 2, "new_value": 2}]

, on a POST, PUT, or DELETE. For example, I'd like the client to be able to update a series of values on one request, as opposed to having to submit multiple requests for each individual update. However, the args and vars parameters being passed to the methods are empty when a request is sent with the JSON payload above. Specifically, args only gets populated from URL args and vars only get populated if the array is accompanied by a key, such as in:

{"update": [{"id": 1, "new_value": 1},{"id": 2, "new_value": 2}]}

While it certainly isn't too much trouble to include that initial key, I was wondering if there's any way to retrieve the JSON objects from the request without having to specify the key so that I could pass a simple array instead?  

Thank you ahead of time for any help.

[Niphlod]

you have to code your own methods.

[Henry Nguyen]

For posterity's sake, I was able to retrieve the array in the request body by using:

import json
my_list = json.loads(request.body.read())

and then iterating through the list items just like any other list. This was taken from http://web2py.com/books/default/chapter/29/04#request under request.body.

Thanks for letting me know that request.restful() wouldn't parse it automatically, Niphlod.

Henry

[Niphlod]

if the content-type of the POST request is application/json, "mylist" would actually be yet parsed into request.post_vars (i.e. you can skip body.read())

[Henry Nguyen]

Niphlod,

That does not appear to be the case, either for request.restful() requests or regular controller requests. For example, consider this controller method:

def test():
    logger.debug(request.env.content_type)
    logger.debug(request.post_vars)
    logger.debug(request.body.read())
    return

With the request data as a JSON array of objects, such as:

[{"id":1, "is_read":true}]

I get the following logs:

2014-10-23 17:51:47,488 DEBUG test.py test():14 : application/json

2014-10-23 17:51:47,490 DEBUG test.py test():15 : <Storage {}>

2014-10-23 17:51:47,490 DEBUG test.py test():16 : [{"id":1, "is_read":true}]

With the data as a JSON object, such as

{"id":1, "is_read":true}

I get the following logs:

2014-10-23 17:54:46,468 DEBUG test.py test():14 : application/json
2014-10-23 17:54:46,469 DEBUG test.py test():15 : <Storage {u'is_read': True, u'id': 1}>
2014-10-23 17:54:46,470 DEBUG test.py test():16 : {"id":1, "is_read":true}

Note that request data is not parsed into request.post_vars. This would make sense to me; since request.post_vars is a Storage object which inherits from a Python dictionary, there would be no dictionary key to store the array value, no?

Henry

[Niphlod]

what web2py version are you on ?

[Henry Nguyen]

I'm on the latest version from the repo, 2.10.0-beta+timestamp.2014.10.16.15.58.50, though I had this issue on the mainline 2.9.11 as well.

Henry

[Niphlod]

ok. got it. usually in APIs you don't post an array, you post an object. automatic parsing works only for objects, not for arrays.