This is a very simple question but can't seem to find a direct answer. I read in a single JSON object. I then want to parse it and be able to directly address a token or a value and then format it for writing a file output, which I will use in another application. I am using C# and the Newtonsoft library.
My code:
JsonTextReader reader = new JsonTextReader(re);
while (reader.Read())
{
if (reader.Value != null)
Console.WriteLine("Value: {0}", "This is the value <Tags>: " + reader.Value);
}
How can I address each line? for example, desc and then Gets a reference to the game world. This must be so commoplace.
Thanks,
johnh
Use the JArray and JObject objects instead, like this:
var json = System.IO.File.ReadAllText("YourJSONFilePath");
var objects = JArray.Parse(json);
foreach(JObject root in objects)
{
foreach(KeyValuePair<String, JToken> tag in root)
{
var tagName = tag.Key;
Console.WriteLine("Value: {0}", "This is the value <Tags>: " + tagName);
}
}
Given a JToken token:
if (token.Type == JTokenType.Object)
{
foreach (var pair in token as JObject)
{
string name = pair.Key;
JToken child = pair.Value;
//do something with the JSON properties
}
}
else if (token.Type == JTokenType.Array)
{
foreach (var child in token.Children())
{
//do something with the JSON array items
}
}
else
{
//do something with a JSON value
}
Have a look at the properties of the reader as it's reading the string. Especially at the TokenType and Value properties. If you really need to read it sequentially that's the way to go. TokenType will be, in order, StartObject, PropertyName, String etc. depending on the node being read. Basically each time you see a PropertyName, the next one will be the property value.
Take note that you'd probably be better off using other techniques but it all depends.
I see that this thread is a bit old... However, #Karl Anderson, your answer was helpful. I just added a little bit to it which was way better than the 3 or 4 nested foreach loops that I had going on... see code below. Thank you for the help!
JArray jsonResponse = JArray.Parse(content);
Debug.WriteLine("\n\njsonResponse: \n" + jsonResponse);
foreach (JObject root in jsonResponse)
{
foreach (KeyValuePair<String, JToken> tag in root)
{
var tagName = tag.Key;
var variable = tag.Value;
Debug.WriteLine("Key: " + tagName + " Value: " + variable);
}
}
Related
I'd like to iterate through a C# dictionary storing nested JSON to retrieve and pass the dictionary key name to a string, in the form of "key1:key1-1:key1-1-1".
After that, a new dictionary is created to use the specially arranged string as its keys.
Finally, desiredDictionary["key:key:key"] = originalDictionary["key"]["key"]["key"].
Please make the answer specific, my apology that I'm new to C# IEnumerable class and JSON.
I've stored the JSON data into a dictionary, the sample JSON is given below.
using System.Web.Script.Serialization;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
......
string jsonText = File.ReadAllText(myJsonPath);
var jss = new JavaScriptSerializer();
//this is the dictionary storing JSON
var dictJSON = jss.Deserialize<Dictionary<string, dynamic>>(jsonText);
//this is the dictionary with keys of specially arranged string
var desiredDict = new Dictionary<string, string>();
......
......
//Here is a sample JSON
{
"One": "Hey",
"Two": {
"Two": "HeyHey"
}
"Three": {
"Three": {
"Three": "HeyHeyHey"
}
}
}
I need help with the process for dictionary key name retrieval, string completion, and new dictionary value passing.
According to the given JSON, desiredDict["Three:Three:Three"] = dictJSON["Three"]["Three"]["Three"] = "HeyHeyHey",
The solution is expected to apply on any similar JSON.
You can use a recursive method to take a JObject and produce a flattened dictionary from it like so:
private static IDictionary<string, string> FlattenJObjectToDictionary(JObject obj)
{
// obtain a key/value enumerable and convert it to a dictionary
return NestedJObjectToFlatEnumerable(obj, null).ToDictionary(kv => kv.Key, kv => kv.Value);
}
private static IEnumerable<KeyValuePair<string, string>> NestedJObjectToFlatEnumerable(JObject data, string path = null)
{
// path will be null or a value like Three:Three: (where Three:Three is the parent chain)
// go through each property in the json object
foreach (var kv in data.Properties())
{
// if the value is another jobject, we'll recursively call this method
if (kv.Value is JObject)
{
var childDict = (JObject)kv.Value;
// build the child path based on the root path and the property name
string childPath = path != null ? string.Format("{0}{1}:", path, kv.Name) : string.Format("{0}:", kv.Name);
// get each result from our recursive call and return it to the caller
foreach (var resultVal in NestedJObjectToFlatEnumerable(childDict, childPath))
{
yield return resultVal;
}
}
else if (kv.Value is JArray)
{
throw new NotImplementedException("Encountered unexpected JArray");
}
else
{
// this kind of assumes that all values will be convertible to string, so you might need to add handling for other value types
yield return new KeyValuePair<string, string>(string.Format("{0}{1}", path, kv.Name), Convert.ToString(kv.Value));
}
}
}
Usage:
var json = "{\"One\":\"Hey\",\"Two\":{\"Two\":\"HeyHey\" },\"Three\":{\"Three\":{\"Three\":\"HeyHeyHey\"}}}";
var jObj = JsonConvert.DeserializeObject<JObject>(json);
var flattened = FlattenJObjectToDictionary(jObj);
It takes advantage of yield return to return the results of the recursive call as a single IEnumerable<KeyValuePair<string, string>> and then returns that as a flat dictionary.
Caveats:
Arrays in JSON will throw an exception (see else if (kv.Value is JArray))
The else part for handling the actual values assumes that all values are convertible to string using Convert.ToString(kv.Value). If this is not the case, you will have to code for extra scenarios.
Try it online
I'm trying to dynamically find the names of leaf nodes of a JSON object whose structure isn't known in advance. First, I'm parsing the string into a list of JTokens, like this:
string req = #"{'creationRequestId':'A',
'value':{
'amount':1.0,
'currencyCode':'USD'
}
}";
var tokens = JToken.Parse(req);
Then I'd like to identify which are leaves. In the above example, 'creationRequestId':'A', 'amount':1.0, and 'currencyCode':'USD' are the leaves, and the names are creationRequestId, amount, and currencyCode.
Attempt that works, but is slightly ugly
The below example recursively traverses the JSON tree and prints the leaf names:
public static void PrintLeafNames(IEnumerable<JToken> tokens)
{
foreach (var token in tokens)
{
bool isLeaf = token.Children().Count() == 1 && !token.Children().First().Children().Any();
if (token.Type == JTokenType.Property && isLeaf)
{
Console.WriteLine(((JProperty)token).Name);
}
if (token.Children().Any())
PrintLeafNames(token.Children<JToken>());
}
}
This works, printing:
creationRequestId
amount
currencyCode
However, I'm wondering if there's a less ugly expression for determining whether a JToken is a leaf:
bool isLeaf = token.Children().Count() == 1 && !token.Children().First().Children().Any();
Incidentally, this is a one-liner in XML.
It looks like you've defined a leaf as any JProperty whose value does not have any child values. You can use the HasValues property on the JToken to help make this determination:
public static void PrintLeafNames(IEnumerable<JToken> tokens)
{
foreach (var token in tokens)
{
if (token.Type == JTokenType.Property)
{
JProperty prop = (JProperty)token;
if (!prop.Value.HasValues)
Console.WriteLine(prop.Name);
}
if (token.HasValues)
PrintLeafNames(token.Children());
}
}
Fiddle: https://dotnetfiddle.net/e216YS
Searched my question and didnt find the answer, I have a JSON file like below:
{
"handle":"ABCD",
"Tracks":{
"Design":{
"rating":402
},
"Development":{
"rating":1584,
"reliability":"n/a"
},
"Specification":{
"rating":923,
"reliability":"0.13"
},
"Conceptualization":{
"rating":895
}
}
}
I am getting a dynamic object of json:
dynamic dynObj;
dynObj = JsonConvert.DeserializeObject(content);
how can I get the name of "Tracks" item? I dont know how many tag like "Design" is there nor I know the name of them...
In your (dynamic) scenario, don't use dynamic, it does not make sense, since you are looking for schema information about the document, which becomes unavailable through the dynamic model.
So, get a JObject by calling JObject.Parse on your JSON data.
Then, get the keys as such (taken from the JObject.Properties documentation):
foreach (var prop in myJObject.Properties())
{
//returns 'handle' and 'Tracks' for your root object
Console.WriteLine("{0} - {1}", prop.Name, prop.Value);
}
Or using the enumerator of the JObject:
foreach (var kvp in myJOBject)
{
Console.WriteLine("{0} - {1}", kvp.Key, kvp.Value);
}
I have some JSON that looks like this
[
{
"MobileSiteContent": {
"Culture": "en_au",
"Key": [
"NameOfKey1"
]
}
},
{
"PageContent": {
"Culture": "en_au",
"Page": [
"about-us/"
]
}
}
]
I parse this as a JArray:
var array = JArray.Parse(json);
Then, I loop over the array:
foreach (var content in array)
{
}
content is a JToken
How can I retrieve the "name" or "key" of each item?
For example, "MobileSiteContent" or "PageContent"
JToken is the base class for JObject, JArray, JProperty, JValue, etc. You can use the Children<T>() method to get a filtered list of a JToken's children that are of a certain type, for example JObject. Each JObject has a collection of JProperty objects, which can be accessed via the Properties() method. For each JProperty, you can get its Name. (Of course you can also get the Value if desired, which is another JToken.)
Putting it all together we have:
JArray array = JArray.Parse(json);
foreach (JObject content in array.Children<JObject>())
{
foreach (JProperty prop in content.Properties())
{
Console.WriteLine(prop.Name);
}
}
Output:
MobileSiteContent
PageContent
JObject obj = JObject.Parse(json);
var attributes = obj["parent"]["child"]...["your desired element"];
foreach (JProperty attributeProperty in attributes)
{
var attribute = attributes[attributeProperty.Name];
var my_data = attribute["your desired element"];
}
The default iterator for the JObject is as a dictionary iterating over key/value pairs.
JObject obj = JObject.Parse(response);
foreach (var pair in obj) {
Console.WriteLine (pair.Key);
}
Using Linq we can write something like:
JArray array = JArray.Parse(json);
foreach (JObject content in array.Children<JObject>())
{
List<string> keys = content.Properties().Select(p => p.Name).ToList();
}
If the JToken key name is unknown, and you only need the key's Value regardless of name, simply use the JToken.Values() method.
The below sample assumes the JToken value is a primitive type - first value found is extracted.
Solution can be extended to support Array values.
JToken fooToken = sourceData.
int someNum = fooToken .Values<int?>().First() ?? 0;
int someString = fooToken .Values<string>().First();
The simplest way is to look at the path of each item in the JSON object.
For Each token As JToken In json
Dim key= token.Path.Split(".").Last
Next
I have a JSON like this one:
{
"name" : "MyCustomName",
"my_node" : {
"name" : "my_node_name"
},
"dict1":"value1",
"dict2":"value2",
"dict3":"value3",
...
}
and an object:
class Node{
string value;
}
class Sample:IDictionary<string, string>{
Node node;
string name;
}
Node and Name in Sample class are always present.
The thing is I don't know how many "dictN" fields will be... and that's the point.
And the question is:
How to Deserialize that JSON to this Object?
Edit: apparently even with field names harmonized, your deserializer just can't cope with specific fields combined with general dictionary fields.
In which case, I'd just advise deserializing as a Dictionary<string, object> and building with the result:
var d = new JavaScriptSerializer().Deserialize<Dictionary<string, object>>(json);
Sample s = new Sample();
s.name = (string)d["name"];
Node n = new Node();
n.value = (string)((Dictionary<string, object>)d["my_node"])["name"];
foreach (var key in d.Keys.Except(new string[] { "name", "my_node" }))
{
s.Add(key, (string)d[key]);
}
INITIAL IDEA
The following is a dictionary serializer. It has one special case of not accepting empty string.
private void SerializePerinatalModel<T>(IDictionary<string, object> dataModel, T perinatalModel)
{
Type sourceType = typeof(T);
foreach (PropertyInfo propInfo in (sourceType.GetProperties()))
{
if (dataModel.ContainsKey(propInfo.Name))
{
// if an empty string has been returned don't change the value
if (dataModel[propInfo.Name].ToNullSafeString() != String.Empty)
{
try
{
Type localType = propInfo.PropertyType;
localType = Nullable.GetUnderlyingType(localType) ?? localType;
propInfo.SetValue(perinatalModel, Convert.ChangeType(dataModel[propInfo.Name], localType), null);
}
catch (Exception e)
{
// ToDo: log update value errors
}
}
}
}
}
but could be made null safe. It does deal with nullable types.
As JSON is essentially a dictionary type then iterating through the top level types should get you there.
This is written in haste so is only a sketch of an idea.
BETTER IDEA
Also try using
foreach (var item in JsonData.Where(m => m.Key.Substring(0,4) == "dict"))
{
// add item to collection
}
might also do the biz.
You can simply have the output in the form of Dictionary<string, object>, try this piece of code instead.
System.Web.Script.Serialization.JavaScriptSerializer s =
new System.Web.Script.Serialization.JavaScriptSerializer();
var nodes = s.Deserialize<Dictionary<string, object>>(jsonString);
var dictNodes = nodes.Where(w => w.Key.StartsWith("dict"));