ohler55/ojg

Is it possible to use JSONPath to pick the objects without a particular field?

denisvmedia opened this issue · 4 comments

denisvmedia commented

I tried this program: https://go.dev/play/p/De9ncvFbK6S:

package main

import (
	"fmt"

	"github.com/ohler55/ojg/jp"
	"github.com/ohler55/ojg/oj"
)

func main() {
	obj, err := oj.ParseString(`[{"name": "Alice", "age": 20}, {"age": 30}, {"name": "Bob"}]`)
	if err != nil {
		panic(err)
	}

	// Define the JSONPath expression to select objects without a "name" field.
	x, err := jp.ParseString("[?(!@.name)]")
	if err != nil {
		panic(err)
	}

	ys := x.Get(obj)
	fmt.Println(ys)
}

It won't panic, but it also just returns all the objects regardless the filter. Is it possible to achieve what I need with your library? Thank you.

ohler55 commented

[?(@.name exists false)] should work but I tried it an it fails so it's a bug and I'll fix it tonight.

  • 👍1
ohler55 commented

Looks like I broke it in the last release when the Nothing value was introduced to be in close compliance with https://datatracker.ietf.org/doc/html/draft-ietf-jsonpath-base. Please try the develop branch for the fix. I'll release on confirmation.

denisvmedia commented

It works. Thank you.

ohler55 commented

Released v1.18.1 with the fix. Thanks for letting me know about the issue.

  • 👍2