Select an array member by name with a JSON Pointer

Question

Is there a way to select an array member the value of a key with JSON Pointer? So for this JSON Schema:

"links":[
    {
      "title": "Create",
      "href": "/book",
      "method": "POST",
      "schema": {}
    },
    {
      "title": "Get",
      "href": "/book",
      "method": "GET",
      "schema": {}
    }
  ]

Instead of:

links/0/schema

I would like to be able to do:

links/{title=GET}/schema

JsonPointers are quite limited. For this kind of query you might want to look at JsonPath. — dnault
– dnault, Commented Sep 15, 2017 at 22:24
I am extremely appalled this question has so little exposure and, as it seems right now, does not have a proper implementation as a resolution for this request. How is it by default expected that each array member has always the same index? — Akito
– Akito, Commented Sep 8, 2020 at 11:31

Community · Accepted Answer · 2021-10-07 11:04:35Z

9

The Json Pointer defined in RFC6901 doesn't allow you to select an array member by name. Here is the only mention of Arrays in the RFC:

If the currently referenced value is a JSON array, the reference token MUST contain either:

* characters comprised of digits ..., or

* exactly the single character "-", making the new referenced
         value the (nonexistent) member after the last array element.

edited Oct 7, 2021 at 11:04

CommunityBot

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answered Sep 21, 2020 at 12:40

Rodrigo Estebanez

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Comments

jabbermonkey · Accepted Answer · 2016-12-22 19:04:24Z

4

Apparently not. So I did this:

const links = schema.links;
  let ref;
  for (const [i, link] of links.entries()) {
    if (link.href === req.originalUrl && link.method === req.method) {
      ref = `schema.json#/links/${i}/schema`;
      break;
    }
  }

answered Dec 22, 2016 at 19:04

jabbermonkey

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Comments

Scott Nieman · Accepted Answer · 2025-06-06 15:28:34Z

0

JSON Pointer is weak for this very reason. JSON Path is much better for this use case.

JSON PATCH unfortunately leverages JSON Pointer, and that too must be updated to be able to use JSON PATH instead. I am sure the authors will have heartburn. But to preprocess the data and then determine the index value to construct the JSON Pointer statement renders it obsolete.

answered Jun 6 at 15:28

Scott Nieman

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1 Comment

ryanwebjackson Jun 6 at 16:10

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