Passing array in GET for a REST call

Question

I have a url to fetch appointments for a user like this:

/user/:userId/appointments

How should the url look like if I want to get appointments for multiple users?

should it be:

/appointments?users=1d1,1d2..

Thanks, Chris.

Answer 1

Collections are a resource so /appointments is fine as the resource.

Collections also typically offer filters via the querystring which is essentially what users=id1,id2... is.

So,

/appointments?users=id1,id2 

is fine as a filtered RESTful resource.

Answer 2

I think it's a better practice to serialize your REST call parameters, usually by JSON-encoding them:

/appointments?users=[id1,id2]

or even:

/appointments?params={users:[id1,id2]}

Then you un-encode them on the server. This is going to give you more flexibility in the long run.

Just make sure to URLEncode the params as well before you send them!

Answer 3

Another way of doing that, which can make sense depending on your server architecture/framework of choice, is to repeat the same argument over and over again. Something like this:

/appointments?users=id1&users=id2

In this case I recommend using the parameter name in singular:

/appointments?user=id1&user=id2

This is supported natively by frameworks such as Jersey (for Java). Take a look on this question for more details.

Answer 4

/appointments?users=1d1,1d2.. 

is fine. It's pretty much your only sensible option since you can't pass in a body with a GET.

Answer 5

This worked for me.

/users?ids[]=id1&ids[]=id2

Answer 6

Instead of using http GET, use http POST. And JSON. Or XML

This is how your request stream to the server would look like.

POST /appointments HTTP/1.0
Content-Type: application/json
Content-Length: (calculated by your utility)

{users: [user:{id:id1}, user:{id:id2}]}

Or in XML,

POST /appointments HTTP/1.0
Content-Type: application/json
Content-Length: (calculated by your utility)

<users><user id='id1'/><user id='id2'/></users>

You could certainly continue using GET as you have proposed, as it is certainly simpler.

/appointments?users=1d1,1d2

Which means you would have to keep your data structures very simple.

However, if/when your data structure gets more complex, http GET and without JSON, your programming and ability to recognise the data gets very difficult.

Therefore,unless you could keep your data structure simple, I urge you adopt a data transfer framework. If your requests are browser based, the industry usual practice is JSON. If your requests are server-server, than XML is the most convenient framework.

JQuery

If your client is a browser and you are not using GWT, you should consider using jquery REST. Google on RESTful services with jQuery.