json-pointer [![Documentation][typedoc-shield]][typedocs]

This package provides a TypeScript and JavaScript implementation of [RFC6901
JavaScript Object Notation (JSON) Pointer][rfc6901].

[typedoc-shield]: https://img.shields.io/badge/typedoc-reference-blue.svg
[typedocs]: https://json-schema-spec.github.io/json-pointer-typescript/
[rfc6901]: https://tools.ietf.org/html/rfc6901

Usage

Construct a JSON Pointer using Ptr.parse, and then evaluate the pointer using
.eval(). You can convert back to a string using .toString().

``ts
import Ptr from "@json-schema-language/json-pointer";

const data = {
path: {
to: {
thing: ["foo", "bar", "baz"]
}
}
};

const pointer = Ptr.parse("/path/to/thing/2");
console.log(pointer.eval(data)); // Output: baz
console.log(pointer.toString()); // Output: /path/to/thing/2
`

If a JSON Pointer points to a non-existent property of its input, then .eval()
will throw EvalError:

`ts
import Ptr, { EvalError } from "@json-schema-language/json-pointer";

const data = {
path: {
to: {
thing: ["foo", "bar", "baz"]
}
}
};

const pointer = Ptr.parse("/path/to/thing/4");
try {
pointer.eval(data);
} catch (err) {
if (err instanceof EvalError) {
console.log(err.instance); // Output: ["foo", "bar", "baz"]
console.log(err.token); // Output: 4
}
}
`

If you're interested in parsing JSON Pointers that might be invalid, you can
catch these errors by looking for InvalidPtrError:

`ts
import Ptr, { InvalidPtrError } from "@json-schema-language/json-pointer";

try {
Ptr.parse(" invalid json pointer");
} catch (err) {
if (err instanceof InvalidPtrError) {
console.error(err.ptr); // Output: invalid json pointer
}
}
``