Get full file paths in ProcessWire ServicesPages API

I'm currently building an app using ProcessWire. I'm using the ServicePages module to expose my data as a REST-like API.

However, all files seem to be outputted like this:

reel_poster: {
    basename: "breakdown-2015-poster.jpg",
    description: "",
    tags: "",
    formatted: false,
    modified: 1468541707,
    created: 1468541707
}

How do I get the actual path / URL of the file referenced? I need to get the path in a JS app, so I can't use the PHP API.

I've also posted this on their forums, but it seems like there's not a lot of activity there.

So, if I read this forum post correctly, the only way to create the URL is by assembling it manually. We need three things to do that:

• The base path for file assets.
• The ID of the page to which the field is attached.
• The image name.

We know that the base path for file assets is /site/assets/files/. We can then do this, given that we have a page object from the API:

var basePath = '/site/assets/files/';
var imagePath = basePath + page.id + '/' + page.image_field.basename;

This should work. I think. Yes. This is tested and works.