Absolute URLs

In some cases, like open graph tags, you are required to use an absolute URL. The trick with this is that you will want it to be correct in development, staging/preview environments, and production.

The recommended way to do this is to use Combine's absolute_url Jinja filter, which requires a variable named base_url.

Setting the base_url variable

In your combine.yml, define the base_url variable so that it's available across your site.

Here's an example:

variables:
  base_url:
    default: "https://combine.dropseed.dev"
    from_env: URL  # netlify

In development, this will be automatically set to http://127.0.0.1:{port} when you run combine work.

In staging or preview environments, the best thing to do is use an environment variable to populate this automatically. In this example we're using the URL environment variable from Netlify.

Production will also use the URL environment varible on Netlify, but setting a default means that combine build will default to the production URL whether or not we run the command on Netlify.

Using the absolute_url filter

With the base_url variable set, you can now use the absolute_url filter to pull everything together and get correct absolute URLs across your site, in every environment.

This works with hard-coded strings:

<meta property="og:image" content="{{ '/static/img/open-graph.png'|absolute_url }}" />

As well as variables:

<meta property="og:image" content="{{ image_url|absolute_url }}" />

Combine also automatically sets the url variable for the current page that is being built. So in templates, you can use that to automatically create an absolute URL to the current page:

<meta property="og:url" content="{{ url|absolute_url }}" />