C # Extract JSON from nested array
I am trying to iterate through nested JSON arrays using C # and JSON.NET. JSON represents categories for an online store - below is an example. My goal is to create a list of all category names.
{
"id": 2,
"parent_id": 1,
"name": "Main Category List",
"is_active": true,
"position": 1,
"level": 1,
"product_count": 0,
"children_data": [
{
"id": 9,
"parent_id": 2,
"name": "Mens Clothing",
"is_active": true,
"position": 6,
"level": 2,
"product_count": 0,
"children_data": []
},
{
"id": 8,
"parent_id": 2,
"name": "Womens Clothing",
"is_active": true,
"position": 7,
"level": 2,
"product_count": 0,
"children_data": [
{
"id": 223,
"parent_id": 8,
"name": "Outdoor Clothing",
"is_active": true,
"position": 1,
"level": 3,
"product_count": 0,
"children_data": []
},
{
"id": 224,
"parent_id": 8,
"name": "Hiking Clothing",
"is_active": true,
"position": 2,
"level": 3,
"product_count": 0,
"children_data": []
},
{
"id": 596,
"parent_id": 8,
"name": "Dresses",
"is_active": true,
"position": 3,
"level": 3,
"product_count": 0,
"children_data": [
{
"id": 694,
"parent_id": 596,
"name": "Summer Dresses",
"is_active": true,
"position": 13,
"level": 4,
"product_count": 0,
"children_data": [
{
"id": 720,
"parent_id": 694,
"name": "Accessories",
"is_active": true,
"position": 1,
"level": 5,
"product_count": 0,
"children_data": [ ]
}
]
}
]
}
]
},
{
"id": 10,
"parent_id": 2,
"name": "Sale & Clearance",
"is_active": true,
"position": 8,
"level": 2,
"product_count": 0,
"children_data": []
}
]
}
There may be different levels of categories here, and I need to parse everything. I want to get each category and create a map. For example (Main list of categories → Clothes for women → Outdoor clothing). I think I can check the depth of the children data, but I don't know how to go deeper and deeper into the next Json object.
JObject responseObject = JObject.Parse(response.Content);
foreach (JObject category in getCatResponseObj.SelectToken("children_data"))
{
while loop checking depth of children_data
}
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This appears to be a recursively defined structure. You must create a function to extract the values of each of the children so that you can reuse it recursively.
IEnumerable<string> GetCategoryNames(JObject data)
{
yield return (string)data["name"];
foreach (var name in data["children_data"].Cast<JObject>().SelectMany(GetCategoryNames))
yield return name;
}
Then call it on the root object so that your names fit into a list or whatever.
var obj = JObject.Parse(response.Content);
var names = GetCategoryNames(obj).ToList();
Otherwise, if you want to indiscriminately get all the names in the object tree, just keep in mind that SelectToken()
/ SelectTokens()
also accepts json path requests. Thus, to get all the names of all descendants, you simply do the following:
let names = obj.SelectTokens("..name").ToList();
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If it were me, I would create the most complete JSON file I could think of (including all possible entries) and then use json2csharp or an equivalent tool to create C # classes, then deserialize the Json and work with it natively. You may have to massage the results a little - but I think you can get there. If that didn't work, I would use the Newtonsofts JSON LINQ functions (documentation) . JToken gives you parent / child combinations that allow you to navigate up and down the tree. The samples in the documentation are really good, so I don't have to fill the page with duplicate information.
(Created from your example)
public class ChildrenData
{
public int id { get; set; }
public int parent_id { get; set; }
public string name { get; set; }
public bool is_active { get; set; }
public int position { get; set; }
public int level { get; set; }
public int product_count { get; set; }
public List<object> children_data { get; set; }
}
public class RootObject
{
public int id { get; set; }
public int parent_id { get; set; }
public string name { get; set; }
public bool is_active { get; set; }
public int position { get; set; }
public int level { get; set; }
public int product_count { get; set; }
public List<ChildrenData> children_data { get; set; }
}
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