I have a big nested JSON. I don't know the structure of the JSON.
I just have a set of keys which are present in the JSON but I don't know where exactly in the JSON.
How do I find out the path of a key from an unknown JSON structure assuming the key exists somewhere in it?
If your JSON structure is unknown, you can parse it into a JToken like this:
JToken token = JToken.Parse(json);
From there, you can use either SelectToken() or SelectTokens() with a recursive descent JsonPath expression to find the property (or properties) matching a key:
JToken match = token.SelectToken("$.." + keyToFind);
Once you have the matching token, you can get the path to it using its Path property:
string path = match?.Path;
Here is a working demo which assumes you have multiple keys to find and each key can appear multiple times in the JSON: https://dotnetfiddle.net/9Em9Iq
For an unknown structure you can iterate over the objects :
var reader = new JsonTextReader(new StringReader(jsonText))
while (reader.Read())
{
// Do a condition on the variables reader.TokenType, reader.ValueType, reader.Value
}
This method will log all paths in your top level json that have a key equal to "key"
var keys = jobject.Properties().Where(p => p.Name == key).ToList();
keys.ForEach(i => Console.WriteLine(i.Path));
This will NOT work in a recursive way but it is easy from this to do a recursive search from there
you can use
JObject o = JObject.Parse(<yourjson>);
dynamic obj = o.SelectTokens("$..Product");
Related
I have the following json
{
"audit_date": "2020-05-13T11:27:10.3187798Z",
"client_uuid": "2fd77dd8-ed76-4bba-b0e1-5cda454c8d6e",
"audit_entry": {
"where_uri": "test.com/dataservice/apps/171f0841-825b-4964-8f8c-0869650f14a6",
"why_uri": "test.com/dataservice/reference/reasons_for_change/61acc173-7168-4ae5-9f04- afa228941f8b",
"who_uri": "test.com/securityservice/users/4977dae1-a307-425f-980c-53413fef1b0f",
"when_audited": "2018-11-13T20:20:39+00:00",
"what_uri": "test.com/dataservice/study_subjects/1bc67a71-8549-4ab8-9dd9-e44238198860",
"what_changed": [
{
"attribute_name": "birth_year",
"attribute_value": "1969",
"attribute_change": null
},
{
"attribute_name": "subject_reference",
"attribute_value": "TEST-WOO3444",
"attribute_change": null
}
]
}
}
But I want to empty the nest array "what_changed"
So I need the output to be
{
"audit_date": "2020-05-13T11:27:10.3187798Z",
"client_uuid": "2fd77dd8-ed76-4bba-b0e1-5cda454c8d6e",
"audit_entry": {
"where_uri": "test.com/dataservice/apps/171f0841-825b-4964-8f8c-0869650f14a6",
"why_uri": "test.com/dataservice/reference/reasons_for_change/61acc173-7168-4ae5-9f04-afa228941f8b",
"who_uri": "test.com/securityservice/users/4977dae1-a307-425f-980c-53413fef1b0f",
"when_audited": "2018-11-13T20:20:39+00:00",
"what_uri": "test.com/dataservice/study_subjects/1bc67a71-8549-4ab8-9dd9-e44238198860",
"what_changed": []
}
}
I have written the following code
JObject jObj = JObject.Parse(jsonText);
jObj["audit_entry"]["what_changed"] = null;
string json = jObj.ToString(Formatting.None);
but this makes the field null rather than empty array.
I have also tried
JObject jObj = JObject.Parse(jsonText);
jObj["audit_entry"]["what_changed"] = "";
string json = jObj.ToString(Formatting.None);
but that still doesn't give an empty array.
I also tried using the Array.Clear() method, but this is a JObject array rather than a normal array.
Arrays are represented by the JArray type, not JObject. Cast the value of "what_changed" to the proper type and use the methods you need. Eg:
JObject jObj = JObject.Parse(jsonText);
JArray changed=(JArray)(jObj["audit_entry"]["what_changed"]);
changed.Clear();
Working with JSON elements is rather unusual though. It's typically a lot easier to deserialize JSON strings into strongly typed objects, modify them as needed and then serialize them back to a string.
Generating the necessary DTOs can be done easily in Visual Studio by selecting Paste Special > Paste JSON as Classes from the Edit menu
I can see several possibilities...
1.- instead of clearing the array, create a new one, an empty one. This does not solve the problem but it is a work around.
2.- using newtonsoft (a nuget package that you can download), you may be able to find different utilities there.
2.1.- Instead of parsing with JObject, parse with JArray, and then use Clear:
https://www.newtonsoft.com/json/help/html/ParseJsonArray.htm
https://www.newtonsoft.com/json/help/html/M_Newtonsoft_Json_Linq_JArray_Clear.htm.
2.2.- use Remove, for this you need the property name, so you need to iterate within the array (a foreach), getting the name of the property, and delete one by one.
https://www.newtonsoft.com/json/help/html/M_Newtonsoft_Json_Linq_JObject_Remove.htm
You need to cast it to a JArray first, then you can use its Clear() method;
((JArray)(jObj["audit_entry"]["what_changed"])).Clear();
Alternatively, you could simply create a new JArray in place of the old one.
jObj["audit_entry"]["what_changed"] = new JArray();
Try this :
JObject jObj = JObject.Parse(jsonText);
JToken jToken = jObj["audit_entry"]["what_changed"];
jToken.Replace(JToken.Parse("[]"));
string json = jObj.ToString(Formatting.None);
I am working with Jsons which I don't know their structure in advanced. Just for example:
{
"OrganizationData": {
"Org1": {
"Name": "Rega And Dodli",
"EmployessNum": "100000000"
},
"Org2": {
"Name": "Sami And Soso",
"EmployessNum": "2"
}
}
}
I'm currently getting values by using the SelectToken method to which I can pass a key with a sub key like this:
var token = myJObject.SelectToken("OrganizationData.Org1")
This works fine. Now I want to add a new entry to the JSON using a string like that, something like:
myJObject.Add("OrganizationData.Org3", myValueJson);
but calling add like that directly just adds a new key to the json called "OrganizationData.Org3" and not creating a new sub key called "Org3" inside "OrganizationData" like the current "Org1" and "Org2".
How can I add a new value with a delimited string like needed?
JSON doesn't have subkeys or delimited keys. OrganizationData.Org1 is a LINQ to JSON search expression, not a subkey.
To add Org3 you can use one of the many ways available to modify a JSON object. You can add a child element to OrganizationData or a sibling to one of the other Org nodes.
To add a child element to a node, you could use .SelectToken("OrganizationData") if you don't already have a reference to it, and use JObject.Add to add the new node. You'll have to cast the result to JObject first, as SelectToken returns a JToken. If there's a chance that OrganizationData is an array, you'll have to check the type too.
For example:
var token = myJObject.SelectToken("OrganizationData");
if(token is JObject orgObj)
{
orgObj.Add("Org3",myValueJson);
}
Working with unknown paths
The same thing works if the path is specified at runtime. In this case, all that's needed is to separate the last part from the rest of the path, perhaps using String.LastIndexOf`:
var lastDot=path.LastIndexOf('.');
if (lastDot<0)
{
//Oops! There's no dot. What do we do now?
}
var parent=path.Substring(0,lastDot);
var key=path.Substring(lastDot+1);
var token = myJObject.SelectToken(parent);
if(token is JObject orgObj)
{
orgObj.Add(key,myValueJson);
}
You'll have to decide what to do if the path contains no dot. Is this an invalid path? Or should a new object be added under the root object?
No idea where to begin with this, so I don't have any sample code.
I need to change the name of a property in a json document.
var json = (#"{""id"":""12"",
""title"":""My Title"",
""Chunks"":[
{
""id"":""137"",
""title"":""Title"",
""description"":""null"",
""selections"":[
{
""id"":""169"",
""title"":""Choice"",
""sort_order"":""null"",
""questions"":[
]
}
]
}
]
}
}
}");
I need to change the "id" that's got the value of 12 to "document_id" and leave the other ids alone. Are there any C# libraries like NewtonSoft that allow you to change the property rather than the property value. Seems like a common scenario but I haven't seen anything close to what I'm trying to do. I suppose I could convert the json to a string and do a replace, but that doesn't seem very elegant.
An approach using Newtonsoft.Json.Linq.JObject would look something like:
var obj = JObject.Parse(json);
obj["document_id"] = obj["id"]; // create new property called "document_id"
obj.Remove("id"); // remove the "id" property
Console.WriteLine(obj);
Also note that your JSON is not valid. It has two extra } at the end.
Assuming you would want to replace all the keys when there could be more than one node with key as "id" and value "12", you could use Linq to identify Tokens with Key "Id" and Value "12" and then use Add/Remove methods for creating a new node with different name.
For example,
JToken node = JToken.Parse(json);
var jObjectsWithTitle = node
.SelectTokens("$..*")
.OfType<JObject>()
.Where(x => x.Property("id") != null && Convert.ToInt32(x.Property("id").Value) == 12);
foreach(var item in jObjectsWithTitle)
{
item.TryGetValue("id",out var currentValue);
item.Add("document_id",currentValue);
item.Remove("id");
}
I'm trying to make a json editor(works with treeview) these days, i did changing value function, i can change some keys as well, but i cant set keys in objects.
I can set the value:
SetValue(ref JObject main,JToken token,JToken newValue) {
//2nd argument is obj.SelectToken(node.Path)
token.Replace(newValue);
}
I can also set some keys:
SetKey(ref JObject main,JToken token,string newKey) {
//2nd argument is obj.SelectToken(node.Path)
//However, if token is in object, it seys the key of object because parent is object
(token.Parent as JProperty).Replace(newKey);
}
But how can i set the keys?
Regards.
You don't need to pass the original root object by ref and you don't need the original root at all. All you care about is the JToken and its parent.
In this case, you want to think of "replacement" as:
Add the old value by new key
Remove the old key/value pair
public void SetKey(JObject parent, JToken token, string newKey)
{
var tokenProp = token as JProperty;
var oldKeyName = tokenProp.Name;
parent[newKey] = tokenProp.Value;
parent.Remove(oldKeyName);
}
We can assume that if you are replacing a key for a key value pair, that the object is a JProperty token. In addition, if we are replacing keys, it is also safe to assume the parent is a JObject. You can call it as such:
var json = "{ 'key1': 'val1' }";
JObject parsedObj = JsonConvert.DeserializeObject<JObject>(json);
SetKey(parsedObj, parsedObj.First, "key2");
I had a similar issue where I had to remove whitespaces from all properties within a JObject, but didn't want to use a helper function. With using System.Linq:
var descendants = jObject.Descendants().Where(attr => attr is JProperty && ((JProperty)attr).Name.Contains(" ")).ToList();
descendants.ForEach(attr => attr.Parent[((JProperty)attr).Name.Replace(" ", string.Empty)] = ((JProperty)attr).Value);
descendants.ForEach(attr => attr.Remove());
I'm working with C#, trying to parse JSON to XML, but first i need to validate the JSON and then check if it have a root element, there is my problem.
Suppose I got these two JSON strings:
string jsonWithoutRoot = "{'name': 'Fran', 'roles':['Admin','Coder']}";
string jsonWithRoot = "{'person': {'name': 'Fran','roles':['Admin','Coder']}}";
I want to get TRUE if the string have a root element like jsonWithRoot and FALSE in the other case.
A JSON string has one root object by definition. You're simply trying to count whether this root object has only one element.
This is trivially done by parsing the JSON into a JObject and getting the element count:
var jObject = JObject.Parse(jsonString);
bool hasOneElement = jObject.Count == 1;
I have been recently using this method to check what you are looking for. It might be helpfull.
public static bool HasOneProperty(string json)
{
JObject jsonObj = JObject.Parse(json);
if (jsonObj.Count > 1)
{
return false;
}
return true;
}