Function to check if a file exists

Feature requests
1

My use case is that I want to have a shortcode to create a <picture> element, but I want to only insert code for files that already exist (the rules for when I use webp or avif are not so easy to express in a static generator and I prefer to handle them separately).

get_file_metadata kind of works as a proxy, but avif support is flaky and I actually don’t care about the metadata, so only checking for the file would be more efficient.

2

Interesting, it shouldn’t be too hard to add but I’m just wondering how many people need that though.

3

Probably it is a very obscure use-case. Sadly, AVIF support is broken in the image crate that zola uses to read the metadata, but I’ll try look into collaborating with that.

4

I’ve found the need for such a function a couple of times while adding/improving multilanguage support on my theme, tabi.

The last case was figuring out whether a page had translations to add hreflang tags to the header of the page.

I solved it (PR #159) by using load_data with required=false first. Not pretty, but it worked:

{# Check if the translated page or section exists #}
{%- set translation_exists = load_data(path=translated_filename, required=false) -%}

{# Get the page or section details #}
{%- if translation_exists -%}
    {%- if page.relative_path -%}
        {%- set translated_page = get_page(path=translated_filename, metadata_only=true) -%}
    {%- else -%}
        {%- set translated_page = get_section(path=translated_filename, metadata_only=true) -%}
    {%- endif -%}
{%- endif -%}

It would be nice, however, to have the optional required argument to get_section, get_page, and/or to get a function to check if a file exists.