Add input URL to the metadata JSON?

[nateify]

Let's say for example I run the command gallery-dl https://danbooru.donmai.us/posts/xyz and my config enables writing metadata to JSON. I would like for "https://danbooru.donmai.us/posts/xyz" to end up somewhere in the JSON.

url-metadata is not suitable since it is a direct image link, for example for Danbooru it starts with https://cdn.donmai.us/original

Most importantly I would like it to be extractor agnostic. So do not want to manually write out per extractor postprocessor with https://danbooru.donmai.us/posts/{id} for example. I tried {extractor.url} and {url} like so but the final value is null:

        "postprocessors": [
            {
                "name": "metadata",
                "mode": "modify",
                "event": "init",
                "fields": {"extractor_url": "{url}"}
            },

With the above example my JSON has "extractor_url": null, in it

[mikf]

Most importantly I would like it to be extractor agnostic

That's not possible until I add another option similar to url-metadata, path-metadata, etc for this.

For Danbooru, you can use "fields": {"extractor_url": "https://danbooru.donmai.us/posts/{id!s}"} to get the post URL.

{extractor.url}

Only available in logging messages at the moment