Javascript JSON serializer Principal support

Developers
1

window.JSON doesn’t support Principals, and I’m wondering if anyone has taken it upon themselves to patch that, write a new serializer, or otherwise come up with a good solution!

A quick search didn’t turn anything up, so apologies if this is a duplicate.

2

Do the fromText and toText methods here help?

1 Like
3

I’m sure they do, yeah. For some context, I’m storing things in local storage and finding Principals revived from that store no longer behave correctly. Luckily the JSON base de/serialize methods provide an API to customize behaviour. Working on a little something rn. Thanks Paul!

4

This does the trick for me.

export function serialize(value: unknown): string {
    return JSON.stringify(value, (key, value) => {
        if (value?._isPrincipal) {
            const principal = {
                _isPrincipal: true,
                value: value.toText(),
            }
            console.log('serialized principal', principal);
            return principal;
        }
        return value;
    });
}

export function deserialize(text: string): unknown {
    return JSON.parse(text, (key, value) => {
        if (value?._isPrincipal) {
            const principal = Principal.fromText(value.value);
            console.log('rebuilt principal', principal);
            return principal;
        }
        return value;
    });
}
2 Likes
5

Hi,

I use Text/String of Principal so

from Motoko to Javascript I use Principal.toText(x) and from Javascript to Motoko on Motoko side Principal.fromText(x)

1 Like