Twitter search api entities with media not working with Json.net for Windows phone Mango silverlight - silverlight

Question

Below is my returned json from twitter
{
"created_at": "Sat, 11 Feb 2012 06:38:28 +0000",
"entities": {
"hashtags": [
{
"text": "Shubhdin",
"indices": [
9,
18
]
}
],
"urls": [],
"user_mentions": [
{
"screen_name": "SAMdLaw",
"name": "Sabyasachi Mohapatra",
"id": 104420398,
"id_str": "104420398",
"indices": [
0,
8
]
}
]
},
"from_user": "nilayshah80",
"from_user_id": 213599118,
"from_user_id_str": "213599118",
"from_user_name": "Nilay Shah",
"geo": {
"coordinates": [
18.6003,
73.825
],
"type": "Point"
},
"id": 168222351106899968,
"id_str": "168222351106899968",
"iso_language_code": "in",
"metadata": {
"result_type": "recent"
},
"profile_image_url": "http://a2.twimg.com/profile_images/1528184590/IMG_0465_normal.JPG",
"profile_image_url_https": "https://si0.twimg.com/profile_images/1528184590/IMG_0465_normal.JPG",
"source": "<a href="http://twabbit.wordpress.com/" rel="nofollow">twabbit</a>",
"text": "#SAMdLaw #Shubhdin mitra",
"to_user": "SAMdLaw",
"to_user_id": 104420398,
"to_user_id_str": "104420398",
"to_user_name": "Sabyasachi Mohapatra",
"in_reply_to_status_id": 168219865197461505,
"in_reply_to_status_id_str": "168219865197461505"
},
{
"created_at": "Sun, 12 Feb 2012 01:54:07 +0000",
"entities": {
"hashtags": [
{
"text": "IWIllAlwaysLoveYou",
"indices": [
88,
107
]
}
],
"urls": [],
"user_mentions": [],
"media": [
{
"id": 168513175187238912,
"id_str": "168513175187238912",
"indices": [
108,
128
],
"media_url": "http://p.twimg.com/Alat1wsCMAAh-wE.jpg",
"media_url_https": "https://p.twimg.com/Alat1wsCMAAh-wE.jpg",
"url": "http://shortener.twitter.com/dRc4dXH3",
"display_url": "pic.twitter.com/dRc4dXH3",
"expanded_url": "http://twitter.com/RIPWhitneyH/status/168513175183044608/photo/1",
"type": "photo",
"sizes": {
"orig": {
"w": 395,
"h": 594,
"resize": "fit"
},
"large": {
"w": 395,
"h": 594,
"resize": "fit"
},
"thumb": {
"w": 150,
"h": 150,
"resize": "crop"
},
"small": {
"w": 340,
"h": 511,
"resize": "fit"
},
"medium": {
"w": 395,
"h": 594,
"resize": "fit"
}
}
}
]
},
"from_user": "RIPWhitneyH",
"from_user_id": 19319043,
"from_user_id_str": "19319043",
"from_user_name": "RIP Whitney Houston",
"geo": null,
"id": 168513175183044608,
"id_str": "168513175183044608",
"iso_language_code": "en",
"metadata": {
"recent_retweets": 8,
"result_type": "popular"
},
"profile_image_url": "http://a2.twimg.com/profile_images/1820957590/images__13__normal.jpg",
"profile_image_url_https": "https://si0.twimg.com/profile_images/1820957590/images__13__normal.jpg",
"source": "<a href="http://twitter.com/">web</a>",
"text": "R-T if you think that the Grammy's should organize an \"R.I.P. Whitney Houston\" tribute. #IWIllAlwaysLoveYou http://shortener.twitter.com/dRc4dXH3",
"to_user": null,
"to_user_id": null,
"to_user_id_str": null,
"to_user_name": null
},
If you noticed Media under entities not available in above 2 and when i tried to call below snippet gives me null reference error
MediaUrl = (from user in tweet["entities"]["media"]
select new mediaUrl
{
shortUrl = (string)user["url"],
longUrl = (string)user["expanded_url"],
url = (string)user["media_url"],
start = user["indices"][0].ToString(),
end = user["indices"][1].ToString(),
mediaType = (string)user["type"],
}).ToList()
Same code work for Entities/URL, Hashtags and mentions but not for Media.
Also tried this -> Get JSON object node but still getting null reference exception.

Answer 1

In first tweet, entities object doesn't have media property, so when evaluating first tweet, your code would be equivalent to :
MediaUrl = (from user in (IEnumerable<JToken>)null
select new mediaUrl
{
shortUrl = (string)user["url"],
longUrl = (string)user["expanded_url"],
url = (string)user["media_url"],
start = user["indices"][0].ToString(),
end = user["indices"][1].ToString(),
mediaType = (string)user["type"],
}).ToList()
which will throw ArgumentNullException because that code does query on null reference collection.

Answer 2

Finally got working. Not appropriate solution but works for me.
I created separate method for parsing Media. Passed Entity as string and in that method i checked is EntityString.Contains Media or not. If yes, then parse media json else returned null. See below Snippet.
if (Entities != string.Empty)
{
if (Entities.Contains("\"media\":"))
{
JObject searchResult = JObject.Parse(Entities);
returnMedia = (from user in searchResult["media"]
select new mediaUrl
{
shortUrl = (string)user["url"],
longUrl = (string)user["expanded_url"],
url = (string)user["media_url"],
start = user["indices"][0].ToString(),
end = user["indices"][1].ToString(),
mediaType = (string)user["type"],
}).ToList();
}
}
This works for me. If you have any better solution then Please let me know.