How to update a collection using json patch

Question

I can't find samples on the way to use JSON Patch to update a collection. In fact, I want to use a method PATCH on a collection REST resource in order to update the associated collection without sending again the whole collection. I wonder if JSON Patch could match to describe the operations to do: mainly add elements or remove elements. Elements are complex, meaning that they aren't primitive elements.

Below there are some more details. Let's take the sample of a resource contacts:

GET /contacts
[
  {
    "id": "1",
    "lastName": "Last name 1",
    "firstName": "First name 1"
  },
  {
    "id": "2",
    "lastName": "Last name 2",
    "firstName": "First name 2"
  },
  {
    "id": "3",
    "lastName": "Last name 3",
    "firstName": "First name 3"
  },
  (...)
]

Here is the PATCH request I would like to use but I'm not sure that is JSON Patch compliant:

PATCH /contacts
[
  {
    "op": "add", "value": {
      "firstName": "my first name",
      "lastName": "my last name"
    }
  },
  {
    "op": "remove", "path": "id=='1'"
  }
]

My main issue is how to identify the element to delete based on its field id. Is there dedicated expression for this? I thought about something like: id=='1'.

Last question: is the response content targeted by JSON Patch?

Thanks very much by avance for your help! Thierry

Answer 1

You should be able to simply use the path for the resource to be deleted.

PATCH /contacts
[
  {
    "op": "add",
    "path": "/-",
    "value": {
      "firstName": "my first name",
      "lastName": "my last name"
    }
  },
  {
    "op": "remove", 
    "path": "/0"
  }
]

Looking around, there seems to be some confusion about this, but the standard says "The "remove" operation removes the value at the target location" with example:

{ "op": "remove", "path": "/a/b/c" }