Merging two JSON objects

[bpawlik]

Is there an easy way to merge two JSON objects? E.g. if they have the same keys then overwrite, otherwise add new?

Thanks,
Bartek

[garrisonhh]

Unfortunately not in the current version! I recently made a branch specifically to deal with meta stuff like this, for now I would point you to the object-reflection branch.

Here's a quick example of how I would copy data from one object to another using two new functions (get_keys and put_copy):

test.json

{
    "first": {
        "a": true,
        "b": false
    },
    "second": {}
}

#define GHH_JSON_IMPL
#include "ghh_json.h"

void main() {
    json_t json;
    json_load_file(&json, "test.json");

    printf("before: %s\n", json_serialize(json.root, false, 2, NULL));

    json_object_t *first = json_get_object(json.root, "first");
    json_object_t *second = json_get_object(json.root, "second");

    size_t num_keys;
    char **keys = json_get_keys(first, &num_keys);

    for (size_t i = 0; i < num_keys; ++i) {
        json_put_copy(&json, second, keys[i], json_get_object(first, keys[i]));
    }

    printf("after: %s\n", json_serialize(json.root, false, 2, NULL));

    json_unload(&json);
}

I'm not perfectly happy with some of the new features yet, so it may or may not look a little different when I merge this branch with master. Hope this is helpful, I will leave this issue open until this kind of functionality is merged.

[bpawlik]

Thanks a lot! I just tried it and it works well.

BTW I still had to revert to using strtod for proper floats parsing. Using object-reflection branch was giving me funny numbers.