I am having trouble working with an API, first time I've worked with one. I've managed to use GET to read the data I need and that part is working perfectly, now I need to deserialize the JSON data I am getting back, and I am using Newtonsoft's JSON .NET library. The problem seems to come when I deserialize the data as its exploding and the debugger isn't being helpful. I tried a few suggestions online but no go, so if someone can enlighten me it'd be appreciated. This is the code:
string url = "";
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream receiveStream = response.GetResponseStream();
StreamReader readStream = new StreamReader(receiveStream, Encoding.UTF8);
string responseData = readStream.ReadToEnd();
var results = JsonConvert.DeserializeObject<dynamic>(responseData);
var id = results["id"].Value;
// var name = results.Name;
When I run it the debugger throws the following exception at the last line of code:
{"Accessed JArray values with invalid key value: \"id\". Array position index expected."}
I am fairly sure that ID exists in the data I am getting back.
Json data I am getting back from Smarty Streets:
[
{
"id": 0,
"candidate_index": 0,
"delivery_line_1": "1600 Amphitheatre Pkwy",
"last_line": "Mountain View CA 94043-1351",
"delivery_point_barcode": "940431351000",
"components": {
"primary_number": "1600",
"street_name": "Amphitheatre",
"street_suffix": "Pkwy",
"city_name": "Mountain View",
"state_abbreviation": "CA",
"zipcode": "94043",
"plus4_code": "1351",
"delivery_point": "00",
"delivery_point_check_digit": "0"
},
]
Your response is an array not a single object. So You should use
JArray results = JArray.Parse(responseData)
to parse the result (like results[0]["id"]). If you go the dynamic way then
dynamic results = JArray.Parse(responseData)
Now, you can use it like results[0].id
Another option is to "Paste JSON as classes" so it can be deserialised quick and easy.
Simply copy your entire JSON
In VS: Click Edit > Paste Special >
Paste JSON as classes
Here is a better explanation n piccas...
https://blogs.msdn.microsoft.com/webdev/2012/12/18/paste-json-as-classes-in-asp-net-and-web-tools-2012-2-rc/
Your result appears to be an array of objects, not an array itself. Try setting id to results["id"][0].Value and see if you get something.
See this: Accessed JArray values with invalid key value: "fields". Array position index expected
Related
I have a Json string like below and this is only a small snippet. The number in quotation marks is a Unix Time which i will need to use to iterate over each object.
{
"result": {
"1534860000": [
"1534860000",
19,
41
],
"1534863600": [
"1534863600",
11,
16
],
"1534867200": [
"1534867200",
2,
5
]
}
}
But when I attempt to extract the data in the arrays I get an error:
System.InvalidOperationException: 'Cannot access child value on Newtonsoft.Json.Linq.JProperty.'
Code:
JObject jsonObj = JObject.Parse(response);
string unixTime = Helpers.ConvertToUnix(yesterday.AddHours(hour)).ToString();
foreach (var obj in jsonObj["result"])
{
var array = obj[unixTime]; //here is where the error occurs
}
Anyone able to shed some light on what I am missing?
If we simplify your example code a little to remove the unixTime element (let's just hardcode it for now), we end up with this:
JObject jsonObj = JObject.Parse(response);
string unixTime = "1534860000";
At this stage, we have jsonObj which refers to the root of the JSON object and has a single property of result. Repeating your foreach here for context:
foreach (var obj in jsonObj["result"])
{
var array = obj[unixTime]; //here is where the error occurs
}
You end up with obj referring to the JSON path of result.1534860000. The problem is you're then looking for a property 1534860000 at this JSON path (result.1534860000.1534860000), which does not exist.
You can just get the value directly, like so:
var array = obj["result"][unixTime]
Of course, this requires some error-checking for ensuring the path exists, etc, but it demonstrates the point.
After some help from Kirk Larkin I thought I would post a code snippet up.
JObject jsonObj = JObject.Parse(response);
int hour = 0;
string unixTime = Helpers.ConvertToUnix(yesterday.AddHours(hour)).ToString();
var array = jsonObj["result"][unixTime];
It now returns the contents of the array.
Hey everyone i'm trying to use the v3 Data Youtube API, already have the Request itself and the response looks like this
{
"items": [
{
"snippet": {
"publishedAt": "2016-12-07T16:04:40.472Z",
"displayMessage": "a"
}
}
]
}
The Problem is that i only want the last Comment and not the whole 200(cant be set lower) my first Idea was to Save the whole Response and Compare it to the next one so i know whats new, but that wont really work out
Ok, so from the comments, I gather you are talking about the Live Streaming API.
What you get back are messages, not comments. And yes, as the doc says, "Acceptable values are 200 to 2000, inclusive. The default value is 500." So, you could get the whole 200, and then sort on the timestamp to get the latest message.
How to do that?
As you are doing this in C#, once you have the json string, you need to use some library such as Json.NET. Once you add a NuGet package reference to this, you will need
using Newtonsoft.Json.Linq;
and say your json string is
var json = #"{
""items"": [
{
""snippet"": {
""publishedAt"": ""2016-12-07T16:04:40.472Z"",
""displayMessage"": ""a""
}
}
,
{
""snippet"": {
""publishedAt"": ""2016-12-12T16:04:40.472Z"",
""displayMessage"": ""b""
}
}
]
}";
Then, as described in this documentation, use JObject.Parse to use LINQ to JSON.
var parsedJson = JObject.Parse(json);
JArray items = parsedJson.SelectToken("items") as JArray;
var sortedItems = items.OrderByDescending(item => item["snippet"]["publishedAt"]);
// sortedItems.First() will give you the item with the newest timestamp
Have put all of this at https://dotnetfiddle.net/ubQAZV.
Alternately, you can use JsonConvert if you prefer to deserialize to strongly-typed code.
More about it here.
I receive this JSON response (but I'm not even sure if this is valid JSON. is it?):
"{\"fields\":\"Name,ParentName,Description,StartDate,EndDate,StartMinute,EndMinute\",\"pos\":0,\"start\":0,\"totalRecords\":1001881,\"data\":[[null,\"AAEC 3400 76142\",null,\"2014-05-15T00:00:00\",\"2014-05-15T00:00:00\",840,1050],[null,\"AAEC 3400 76142\",null,\"2014-05-28T00:00:00\",\"2014-05-28T00:00:00\",840,1050],[null,\"ACCT 5400 25030\",null,\"2014-01-08T00:00:00\",\"2014-01-08T00:00:00\",1215,1290],[null,\"ACCT 5400 25030\",null,\"2014-02-19T00:00:00\",\"2014-02-19T00:00:00\",1215,1290]]}"
Is it possible to deserialize this response and access particular values using Newtonsoft JSON package, with or without the LINQ namespace? Can I access specific values from the "data" key?
Currently, my approach is to manipulate this JSON response into regular JSON, so instead of just having a "fields" key and a "data" key followed by lists of values, I end up deserializing normal JSON key/value pairs (like "Name":"null", "ParentName":"AAEC 3400 76142\", . . . ). Then I can access each object in the list's values by key.
But is it possible to access specific values keeping the response the way it came, without parsing/manipulating it, using Newtonsoft JSON package with/without methods in LINQ namespace?
This is how I'm deserializing the json string that I parse/manipulated manually into normal JSON:
var myList = JsonConvert.DeserializeObject<List<MyClass>>(json);
Then I can access values by key off of specific objects in the response by index:
String name = myList[0].Name;
But can I access the value of myList[0].Name without reformatting the JSON response into typical key:value pairs? Does Newtonsoft provide a way to access the value I want from the response the way it came?
Looks like that JSON has been double-serialized. I.e. some class was serialized as a JSON string, then that string was serialized as JSON again, causing JSON control characters including {,} and " characters to be escaped.
This is almost certainly a bug on the server side, you should try to get it fixed there. But if you cannot (for political reasons, say), you can check for this and work around it on the client side:
var token = JToken.Parse(json);
if (token.Type == JTokenType.String)
token = JToken.Parse((string)token);
var myList = token.ToObject<List<MyClass>>();
Update: your root JSON container is an object, not an array, so ToObject<List<MyClass>> won't work. The unwrapped JSON looks like:
{
"fields": "Name,ParentName,Description,StartDate,EndDate,StartMinute,EndMinute",
"pos": 0,
"start": 0,
"totalRecords": 1001881,
"data": [
[
null,
"AAEC 3400 76142",
null,
"2014-05-15T00:00:00",
"2014-05-15T00:00:00",
840,
1050
],
// More of the same
]
}
If you wanted to reformat that into a more traditional array of JSON objects, you could restructure your root JToken like so:
var token = JToken.Parse(json);
if (token.Type == JTokenType.String)
token = JToken.Parse((string)token);
var fields = (string)token.SelectToken("fields");
var fieldList = fields.Split(',');
var root = new JArray();
root.Add(token.SelectTokens("data[*]").OfType<JArray>().Select(a => new JObject(a.Zip(fieldList, (t, s) => new JProperty(s, t)))));
Debug.WriteLine(root);
With the result:
[
{
"Name": null,
"ParentName": "AAEC 3400 76142",
"Description": null,
"StartDate": "2014-05-15T00:00:00",
"EndDate": "2014-05-15T00:00:00",
"StartMinute": 840,
"EndMinute": 1050
},
// More of the same
]
Yes. It is straightforward and simple to deserialize a JSON response formatted in this way using the Newtonsoft JSON package with LINQ namespace. You don't have to manipulate the response string by hand. Set the JSON response string to a string object named "response", use JObject.Parse() to create a dynamic object "jobject", then you can access the "data" JSON key and set it to a JArray object. Then you can loop through each JToken in "jArray". Finally, get the values by their index in the JArray:
dynamic jobject = JObject.Parse(response);
JArray jArray = jobject.data;
foreach (JToken appointment in jArray)
{
parentName = appointment[1];
startMinute = appointment[5];
. . .
}
I'm working with an API that is returning JSON.
I have a method that calls the api, and parses the JSON response for the desired nodes.
Up to this point everything has been working fine, except the latest JSON response appears to be malformed.
Other responses come back like:
{
"Keyword":"\"marhope\"",
"TermKey":null,
"Customers":[
{
"Memberships":[ ],
"CompanyId":0,
"ObjectId":112974,
"ObjectType":"Customer",
}
]
}
I use JObject.Parse to bring back the appropriate nodes by name.
The latest JSON response comes back as:
{
[
{
"AnimalId":9079117,
"SpeciesCode":"XX",
}
]
}
As you can see, there is no "name", and the JSON is slightly invalid.
How can I parse this. For the first example I was using the code below, but now that the JSON has no "name", I don't know how to approach this, thoughts?
JObject results = JObject.Parse(csr.SearchCustomer(1, 1, 870, term));
foreach (var resp in results["Customers"])
{
string obj = (string)resp["CompanyId"];
}
Jon Skeet is correct, the second JSON is invalid: you cannot have an array directly inside an object with no property name. The best course of action is to get the API developers to fix the JSON. However, if you're just looking for a quick and dirty workaround, you could strip off the the first and last brace from the invalid JSON and then parse it as an array using JArray.Parse.
string json = #"{
[
{
""AnimalId"":9079117,
""SpeciesCode"":""XX"",
}
]
}";
json = json.Substring(1, json.Length - 2);
JArray array = JArray.Parse(json);
foreach (JObject item in array.Children<JObject>())
{
Console.WriteLine("AnimalId: " + item["AnimalId"]);
Console.WriteLine("SpeciesCode: " + item["SpeciesCode"]);
}
In the JSON string below, how do I access the values of the "at" and "current_value" properties within the "datastreams" array ?
In this example, there is only one datastream but in reality there could be many. I need to access the datastream by "id" property. Once I figure out this issue, I plan to use a where clause with the id == to the id of the desired datastream.
I tried using the approach discussed here, under "JSON in Windows 8 – A Simpler Approach" but it's not working.
In this code, json contains the JSON returned from the service I'm calling. prop is populated with a JsonArray. current results in an exception with an inner message of "JSON value not found"
var json = JsonObject.Parse(responseBodyAsText);
var prop = json.GetNamedArray("datastreams");
var current = from p in prop
select new
{
datastream = p.GetObject().GetNamedString("datastreams"),
datetime = p.GetObject().GetNamedString("at"),
value = p.GetObject().GetNamedString("current_value")
};
Here is the JSON string:
{
"title":"X",
"status":"X",
"creator":"X",
"datastreams":
[
{
"at":"x",
"max_value":"X",
"current_value":"X",
"id":"X",
"min_value":"X"
}
],
"location":{"exposure":"x","domain":"x","disposition":"x","lat":X,"lon":-X},
"created":"X",
"tags":["X"],
"feed":"X",
"private":"X",
"id":X,
"description":"X",
"version":"X",
"updated":"X"
}
datastream = p.GetObject().GetNamedString("datastreams")
The code above should return an array of objects. You'll need to loop through the array of objects to check the value of each object's "at" and "current_value" properties.
datastream return an array as you can notice by [ ] so:
datetime = datastream[0].at
value = datastream[0].current_value