Runtime: Add JsonPath support to JsonDocument/JsonElement

[gary-holland]

Hi,

I'd like to request JsonPath support for querying the JsonDocument/JsonElement classes. JsonPath provides similar capability to XPath (and even Sql) in that it allows queries to be performed against Json documents. This currently represents a major gap for us shifting from Newtonsoft to system.text.json, as we provide JsonPath values as an input parameter to a data load process which can't be worked around via code.

The JsonPath syntax is described here.

The equivalent functionality in the Newtonsoft library is:

var jsonPath = "$.my.path";
var json = JToken.Parse(jsonString);
var token = json.SelectToken(jsonPath);

The following proposed syntax would work well in the JsonDocument structure:

var jsonPath = "$.my.path";
var jsonDoc = JsonDocument.Parse(json);
var element = jsonDoc.SelectElement(jsonPath); //returns JsonElement
var elements = jsonDoc.SelectElements(jsonPath); //returns JsonElement.ArrayEnumerator

Thanks.

[dazinator]

Just searched for a similar thing myself. The appropriate newtonsoft documentation for this: https://www.newtonsoft.com/json/help/html/QueryJsonSelectTokenJsonPath.htm

[dkmiller]

Seconding this. It would be extremely useful.

[NickMSW]

Would also like to push this up the stack. We want to use system.text.json but the lack of JsonPath is blocking us.

[azambrano]

In the meantime. I'm doing some experiment following the same strategy of the Json.net for support JsonPath but using System.Text.Json.JsonDocument https://github.com/azambrano/JsonDocumentPath

[NinoFloris]

@layomia did this and writedom move out of scope for 5.0?

[zmhh]

If this is implemented it would be nice to have the option for case insensitivity.

[Laiteux]

We want this

[onionhammer]

This would be very useful

[blushingpenguin]

I've ported the Newtonsoft.Json implementation to work with JsonDocument, along with the tests.

nuget: https://www.nuget.org/packages/BlushingPenguin.JsonPath/
source: https://github.com/blushingpenguin/BlushingPenguin.JsonPath/

[Laiteux]

I've ported the Newtonsoft.Json implementation to work with JsonDocument, along with the tests.

nuget: https://www.nuget.org/packages/BlushingPenguin.JsonPath/
source: https://github.com/blushingpenguin/BlushingPenguin.JsonPath/

Hello, what's the difference with this? https://github.com/azambrano/JsonDocumentPath

[blushingpenguin]

It's pretty similar (it's also a port of Newtonsoft.Json's implementation), but is missing some of the functionality of the original and lacks a nuget package. (AFAIK I've ported all of the original functionality).

I could have forked that one, but my version is actually a port of https://github.com/blushingpenguin/MongoDB.Bson.Path (which is a version that works on the MongoDB.BsonDocument family).

[gregsdennis]

More support for JSON Path

[GF-Huang]

Does it merged into .NET 5?

[gregsdennis]

@ADustyOldMuffin, what's with the downvote without an explanation?