RESTful - when should I use POST and GET?

Question

This is my WCF service, where user can find message for him. Simple:

    [OperationContract]
    [WebGet(UriTemplate = "/GetMessages/{UserGLKNumber}/{UserPassword}/{SessionToken}")]
    Messages GetMessages(string SessionToken, string UserPassword, string UserGLKNumber);

I have concerns about that line: {UserGLKNumber}/{UserPassword}/{SessionToken}

I have to authenticate user, before he get that messages. But with GET method, I cannot send objects, like in POST.

Is it consistent with REST pattern?

Please, clear up my doubts.

Answer 1

There are already posts & question about this, I am summarizing all of them

1. POST verb is used when are you creating a new resource (a file in your case) and repeated operations would create multiple resources on the server. This verb would make sense if uploading a file with the same name multiple times creates multiple files on the server.

   PUT verb is used when you are updating an existing resource or creating a new resource with a predefined id. Multiple operations would recreate or update the same resource on the server. This verb would make sense if uploading a file with the same name for the second, third... time would overwrite the previously uploaded file.

2. POST everytime you are modifying some state on the server like database update, delete. GET for readonly fetching like database select.

3. GET: Get a collection of entries (as a feed document) or a single entry (as an entry document).

   POST: Create a new entry from an entry document.

   PUT: Update an existing entry with an entry document.

   DELETE: Remove an entry.

Source:Difference between PUT and POST using WCF REST

Another Useful reads are:

What's the difference between a POST and a PUT HTTP REQUEST?

http://www.codeproject.com/Articles/105273/Create-RESTful-WCF-Service-API-Step-By-Step-Guide

http://msdn.microsoft.com/en-us/magazine/dd315413.aspx

http://social.msdn.microsoft.com/Forums/vstudio/en-US/643e0d8b-80bb-45eb-8a84-318ac8de4497/difference-between-the-rest-verbs-put-and-post?forum=wcf