Django-tastypie creating a URL hierarchy - django

I'd like to create a URL hierarchy using Tastypie but am running into some errors. Here's how I'd like the hierarchy to work:
/recipe
/recipe/ID
/recipe/ID/spice
/recipe/ID/spice/ID
I can't find out how to do this. When I set this up following the Tastypi instructions my URLs would be like this:
/recipe
/recipe/ID
/spice
/spice/ID
If I change the resource_name for spice to "/recipe/spice" then I get a "NotFound: Invalid resource lookup data provided (mismatched type)" error.
Any suggestions about what I could do?

Tastypie is meant to help implement a REST API, and thus by default only supports URLs that conform to REST practices. Namely, each URL should contain a resource name ('recipe' or 'spice') and optionally an identifier for that resource ('ID'). Anything outside of this breaks from REST practices and if you're not implementing a REST API you may want to re-consider whether or not you should be using Tastypie.
That being said, Tastypie does provide a ton of hooks for customizing things. For custom URLs, you'll want to define the method override_urls to map certain URLs to custom views and do some pre-processing before sending it to the regular dispatchers.
If possible, I'd recommend just using standard REST practices and break things up as separate 'recipe' and 'spice' resources. If you need to filter on recipes based on spices that are in them, 'spices' should be passed in as a GET parameter rather than part of the base URL. Hope that helps.

Related

What's the correct way to create a REST service that allows for different types of identifiers?

I need to create a RESTful webservice that allows for addressing entities by using different types of IDs. I will give you an example based on books (which is not what I need to process but I want to build a common understanding this way).
Books can be identifier by:
ISBN 13
ID
title
I can create a book by POSTing to /api/v1/books/The%20Bible. This book can then later be addressed by its ISBN /api/v1/books/12312312301 or ID /api/v1/books/A9471IZ1. If I implemented it this way I would need to analyze whatever identifier gets sent and convert it internally.
Is it 'legal' to add the type of identifier to the URL ? Like /api/v1/books/title/The%20Bible?
It seems that what you need is not simply retrieving resources, but searching for them by certain criteria (in your case, by ISBN, title or ID). In that case, rather than complicate your /books endpoint (which, ideally, should only returns books by ID), I'd create a separate /search function. You can then use it search for books by any field.
For example, you would have:
GET /search?title=bible
GET /search?isbn=12312312301
It can even be easily expanded to add more fields later on.
First: A RESTful URl should only contain nouns and not verbs. You can find a lot of best-practices online, as example: RESTful API Design: nouns are good, verbs are bad
One approach would be to detect the id/identifier in code.
The pattern would be, as you already mentioned:
GET /api/v1/books/{id}, like /api/v1/books/12312312301 or /api/v1/books/The%20Bible
Another approach, similar to this.lau_, would be with a query parameter. But I suggest to add the query parameter to the books URL (because only nouns, no verbs):
GET /api/v1/books?isbn=12312312301
The better solution? Not sure…
Because you are selecting “one book by id” (except title), rather than performing a query/search, I prefer the first approach (…/books should return “a collection of books” and .../books/{id} should return only one book).
But maybe someone has a better approach/idea?
Edit:
I suggest to avoid adding the identifier to the URL, it has “bad smell”. But is also a possible approach and I saw that a lot in other APIs. Let’s see if I can find some information on that, if its “ok” or should be avoided.
Edit 2:
See REST API DESIGN - Getting a resource through REST with different parameters but same url pattern and REST - supporting multiple possible identifiers

Best practice for implementing GET operation in Restful service

I am trying to find if there is any best practices involved in developing/implementing a GET operation.
I was going through the web resource documentation of jersey.
URL : http://jersey.java.net/nonav/apidocs/1.4/jersey/com/sun/jersey/api/client/WebResource.html
If we look at the methods that are available, the 'get' doesn't accept entity.
Is it recommended to implement get operation which doesnt accept entity but only get request parameters from Query Parameters?
Thanks,
GK
Yes. Think of the URI as the unique identifier to the object/resource you are GETing. I typically use query params for a GET if required. More normally I just have a GET something like this: GET: https:/myservice.com/myobject/id. This path is usually returned from a PUT or POST operation on MyObject. If I want to look up one or more I then use query params for the criteria.
There are a number of best practices out there. One that seems to bring together most of the common ones in a readable format is provided by Apigee. You can obtain it from http://info.apigee.com/Portals/62317/docs/web%20api.pdf

Emberjs New routing and query string or custom route matcher

I'm trying to migrate my app to the new emberjs routing API.
With old router I had some workarounds to provide similar URI for objects saved by ID and for new objects which described by set of params. This were done for ability of exchange links to objects between users without permanently saving it. This is two simplified valid routes from my app:
/objects/12 // fetch object by id (/objects/:object_id)
/objects/<serialized params> // build new object from params (/objects/:params)
Both of this routes are similar to router because they all have dynamic parts and static parts are equal. So I wrote custom RouteMatcher to pickup right route. Lack of query string parsing forced me to do this hack as quick and semilegal solution, also there is ancient ticket about this feature on github.
With the new router matching has been extracted to separate package (route-recognizer) so I cannot do the trick (or it will be full of hacks and injections).
As I can see I have to choose from these options:
Totally rewrite my URIs and separate all intersecting routes
Rewrite URIs but try to implement query string parser for the new Ember.Router
Put all logic into one route and reimplement only serialize/deserialize methods (something dirty)
Second solution seems to be more clean.
What will be the best non complicated decision? Should I try to find another way?
The current router does not support query-string parameters.
We are tracking this bug at https://github.com/emberjs/ember.js/issues/1773. You may want to follow it.
In the meantime, your best bet is probably to use a dynamic segment and manually serialize (with the serialize hook) and deserialize (with the model hook).

fake a request in Django

I have a Django equipped with Tastypie and under REST style it's not easy to combine objectes of different types together, so I'm thinking if it's posible to provide a special view for combining response of several REST urls into a bigger JSON object and return to client. The url may look like,
http:// domain.com /combined_view/?p={rest url 1...}&p={rest url
2...}&p={rest url 3...}
and returned JSON would be,
[ {response of rest url 1...},
{response of rest url 2...},
{response of rest url 3...},
...
]
The question is, inside a normal django view, how can I fake a request object, and process it into a response object? Thx.
Calling your own RESTful API from inside your view is a waste of resources. Directly access the objects using the database ORM instead.
Also unrelated Resources/Objects are supposed to be not combined together. If you think that the models should be combined together then maybe your model needs to take care of it and have a relation combining the two.
And to answer your question directly, you can call your urls using httplib2 and parse the response.
I urge you to reconsider whatever it is that your doing, because whatever answer we give you here is bound to go directly against the resourceful design of REST interfaces.
If you have Foo, Bar and Baz models and you create equivalent resources for them, it's impossible to generate a request that's going to return a mixed collection of Foo, Bar, Baz resources, unless these are nested resources in a joint relationship.
Your either not thinking in a resourceful manner or don't need to, but definitely don't turn RESTful architectures into something they haven't been designed for.

Best way to move API from CodeIgniter to Django

In the beginning we made a project using CodeIgniter and we had some controllers that were used to connect an external NAS to the database via it's web interface, to cut a long story short we had a bunch of URL that required an API key to have access to avoid general hackery from outside sources calling the API.
The API existed for various tasks the NAS had to do (manage orders, upload data/images etc.), so we had a few different controllers (ie. one for Orders, Images, etc.) So the API folder looked something like this:
controllers/apiv1/
orders.php
images.php
...
Something along the lines of this:
class Orders extends ApiController {
function Orders()
{
parent::ApiController();
}
function get_paid()
{
$shop = self::get_shop();
$this->load->model('order');
echo json_encode($this->order->by_status($shop->shop_id, Order::STATUS_PAID));
}
}
Where the ApiController just checked the APIKey against the Shop that it was trying to access.
Now we are moving the project to Django, and I was just wondering the be way to setup this api again. I was thinking of making an API app for the project and importing the models in to the views.py and make some functions for everything, my problem here is there a way to break everything up nicely (into separate files for each of the various things)? Or should I just have the views.py full of everything and worry about it in the urls.
Or is there a better way? If possible I would like to separate the api into versions like (api/v1, api/v2, etc.) so that we can just route the urls to the new api without affecting the old. This may come in handy if we have various NAS's using different versions of the API (Hard to explain why...)
You could try using something like Django Piston or Django-tastypie to quickly get something working. The big advantage over using normal Django views is that you get most of the CRUD and serialization to JSON/Yaml/XML done for you.
Tastypie comes with a built-in shared-secret key authentication mechanism, and it's not difficult to find the equivalent code for Piston.
EDIT: BTW, I've been working with both Piston and Tastypie recently. I find Tastypie is easier to setup and the code base looks cleaner. That said, it lacks some features (coming on 1.0 though) that makes it impossible for me to use it at the moment. Piston is very easy to shoehorn into whatever you need, but the code seems to be growing stagnant, the author doesn't seem to be very responsive about open issues and you'll probably end up having your own fork with the bugfixes you need for your application to work properly. Not an ideal situation.