Facebook Api Using F#

A common requirement for modern user-facing applications is to interface with Facebook.  Unfortunately, Facebook does not make it easy on developers –> in fact it is one of the harder apis that I have seen.  However, there is a covering sdk that you can use, along with some hoop jumping, to get it working.  The problem is one of assumptions.  The .NET sdk assumes that you want to build a Windows Store or Phone app and it is human to facebook connections.  Once you get past those assumptions, you can do pretty well.

The first thing you need to do is set up a Facebook account.

Then register as a developer and create an application

In Visual Studio, Nuget in the facebook sdk

Then, in the REPL add the following code to get the auth token

 1 #r "../packages/Facebook.7.0.6/lib/net45/Facebook.dll"
 2 #r "../packages/Newtonsoft.Json.7.0.1/lib/net45/Newtonsoft.Json.dll"
 3 
 4 open Facebook
 5 open Newtonsoft.Json
 6 
 7 type Credentials = {client_id:string; client_secret:string; grant_type:string;scope:string}
 8 let credentials = {client_id="123456";
 9                    client_secret="123456";
10                    grant_type="client_credentials";
11                    scope="manage_pages,publish_stream,read_stream,publish_checkins,offline_access"}
12 
13 
14 let client = FacebookClient()
15 let tokenJson = client.Get("oauth/access_token",credentials)
16 type Token = {access_token:string}
17 let token = JsonConvert.DeserializeObject<Token>(tokenJson.ToString());

Which gives

Once you get the token, you can make a request to user and post to the page

1 let client' = FacebookClient(token.access_token)
2 client'.Get("me")
3 
4 let pageId = "me"
5 type FacecbookPost = {title:string; message:string}
6 let post = {title="Test Title"; message = "Test Message"}
7 client'.Post(pageId + "/feed", post)
8 

I was getting this message though

So then the fun part.  Apparently, you need to submit your application to the facebook team to be approved to be used.  So now I have to submit icons and a description on how this application will be used before I can make a POST.  <sigh>

Thanks to Gene Belitski for his help on my question on Stack Overflow