fb controller

FacebookCTRL.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using Newtonsoft.Json;

namespace dlitfass.Data
{
    public class FacebookController
    {
        private string graphUrl;

        private string accessToken;

        System.Net.WebClient wc;

        public FacebookController(string pAccessToken = null)
        {
            graphUrl = Global.FbGraphUrl;
            accessToken = Global.FbAccessToken;

            if (pAccessToken != null)
            {
                accessToken = pAccessToken;
            }
            // initialize WebClient
            wc = new System.Net.WebClient();
        }

        public string GetBiggestImageByPostFBID(string fbid)
        {
            string objectID = fbidRequest(fbid, "object_id"); // Get ObjectID by FBID

            return getBiggestImage(objectID);
        }

        public string GetBiggestImageByPhotoFBID(string fbid)
        {
            //string objectID = fbidRequest(fbid, "object_id"); // Get ObjectID by FBID

            return getBiggestImage(fbid);
        }
        
        public string GetBiggestImageByEventFBID(string fbid)
        {
            string coverID = fbidRequest(fbid, "cover", "cover_id"); // Get ObjectID by FBID

            return getBiggestImage(coverID);
        }

        public List<String> GetImagesFromAlbum(string fbid)
        {
            string request = fbid + "?fields=photos.fields(images,source,picture,link,name).limit(100)";
            string result = apiRequest(request);

            List<String> retval = new List<string>();

            if (result == null)
            {
                return null;
            }
            try
            {
                var json = JsonConvert.DeserializeObject<dynamic>(result);
                var data = JsonConvert.DeserializeObject<dynamic[]>(json["photos"]["data"].ToString());
                int i = 0;
                while (true)
                {
                    if (data[i] != null)
                    {
                        retval.Add(data[i]["images"][0]["source"].ToString());
                        i++;
                    } else
                    {
                        break;
                    }
                }

            }
            catch (Exception e)
            {
                Help.Diagnostics.WriteToLogFile(e.ToString(), 1001);
            }

            return retval;
        }

        #region private methods (helpers)

        //private void Log(string text)
        //{
        //    Help.Diagnostics.WriteStaticInfoToLogFile(text, @"D:\dev\projects\git\dlitfass\dlitfass.Web\test.txt");
        //    //TappDiag.Log.Diagnostic.WriteInfoLog("1001", "FacebookController->GetImagesFromAlbum", "test ");
        //    //Help.Diagnostics.WriteStaticInfoToLogFile("test3", @"\\chayns1\SlitteRessource\Log\dlitfassContent\26-1-2015-Error.log");
        //}
        /// <summary>
        /// 
        /// </summary>
        /// <param name="fbid"></param>
        /// <param name="property"></param>
        /// <returns></returns>
        private string fbidRequest(string fbid, string property, string selectVal = null) 
        {
            //string request = fbid + "?fields=" + property;
            if (property == "cover")
                fbid = fbid + "?fields=cover";
            string result = apiRequest(fbid);

            if (result == null)
            {
                return null;
            }

            var json = JsonConvert.DeserializeObject<dynamic>(result);

            if (selectVal != null)
            {
                if (json[property] != null)
                    return json[property][selectVal];
                return null;
            }

            return json[property];
        }

        private string getBiggestImage(string fbid)
        {
            //string request = fbid + "?fields=images";
            if (fbid == null) return null;

            string result = apiRequest(fbid);

            if (result == null)
            {
                return null;
            }

            var json = JsonConvert.DeserializeObject<dynamic>(result);
            var data = JsonConvert.DeserializeObject<dynamic[]>(json["images"].ToString());

            return data[0]["source"]; // TODO is the first image always the biggest? (actually yes)
        }

        /// <summary>
        /// performs the Facebook API requests
        /// adds graph uri and access token automatically
        /// </summary>
        /// <param name="endpoint">endpount uri (without https and host) and GET Query String (and without token)</param>
        /// <returns>null on error otherwise result string</returns>
        private string apiRequest(string endpoint)
        {
            if(endpoint == null)
            {
                return null;
            }

            string resultString; // TODO is "" == null ?

            try
            {   
                string stringDelimeter = (endpoint.IndexOf("?") > -1) ? "&" : "?";
                string accessTokenQueryString = stringDelimeter + "access_token=" + accessToken;

                string requestUri = graphUrl + endpoint + accessTokenQueryString;

                resultString = wc.DownloadString(requestUri);
                return resultString;
            }
            catch (Exception e)
            {
                // TODO write Error Log(s)
                // but not here cause here the fb token is most likely expired
                return null;
            }
        }

        #endregion
    }

}