Debugging Tastypie

There are some common problems people run into when using Tastypie for the first time. Some of the common problems and things to try appear below.

“I’m getting XML output in my browser but I want JSON output!”

This is actually not a bug and JSON support is present in your Resource. This issue is that Tastypie respects the Accept header your browser sends. Most browsers send something like:

Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8

Note that application/xml is the first format that Tastypie handles, hence you receive XML.

If you use curl from the command line, you should receive JSON by default:

curl http://localhost:8000/api/v1/

If you want JSON in the browser, simply append ?format=json to your URL. Tastypie always respects this override first, before it falls back to the Accept header.

Querying using Tastypie’s methods isn’t working/returning multiple objects

When calling obj_get (or another method that uses it, such as dispatch_detail), mke sure the fields you’re querying with are either Meta.detail_uri_name or a field which appears in Meta.filtering

“What’s the format for a POST or PUT?”

You can view full schema for your resource through Inspecting The Resource’s Schema.

In general, Tastypie will accept resources in the same format as it gives you. This means that you can see what any POST or PUT should look like by performing a GET of that resource.

Creating a duplicate of an entry, using Python and Requests:

import requests
import json

response = requests.get('http://localhost:8000/api/v1/entry/1/')
event = json.loads(response.content)

del event['id'] # We want the server to assign a new id

response = requests.post('http://localhost:8000/api/v1/entry/',
                         data=json.dumps(event),
                         headers={'content-type': 'application/json'})

The new event should be almost identical, with the exception of readonly fields. This method may fail if your model has a unique constraint, or otherwise fails validation.

This is less likely to happen on PUT, except for application logic changes (e.g. a last_update field). The following two curl commands replace and entry with an copy:

curl -H 'Accept: application/json' 'http://localhost:8000/api/v1/entry/1/' | \
curl -H 'Content-Type: application/json' -X PUT --data @- "http://localhost:8000/api/v1/entry/1/"

You can do this over an entire collection as well:

curl -H 'Accept: application/json' 'http://localhost:8000/api/v1/entry/?limit=0' | \
curl -H 'Content-Type: application/json' -X PUT --data @- "http://localhost:8000/api/v1/entry/"