问题:

How can I use Jekyll to test for the existence of a file?

To clarify, I want to run an {% if %} statement to check if an image file exists with the same name as the page I am on.

On my page in the YAML front matter:

----
  reference-design: true
----

In my layout:

{% if page.reference-design %}
    {% assign filename = page.path | remove_first: '.html' %}
    <!-- How can I check if file actually exists? -->
    <img src="images/reference_designs/{{ filename }}.png">
{% endif %}

回答1:

As of Jekyll 2, all site files are available via site.static_files. You can use this to check if a file exists. For example:

{% for static_file in site.static_files %}
    {% if static_file.path == '/favicon.ico' %}
        {% assign favicon = true %}
    {% endif %}
{% endfor %}

回答2:

This plugin worked for me: https://github.com/Wolfr/jekyll_file_exists

After you install it, you can use it like:

{% if page.reference-design %}
    {% assign filename = page.path | remove_first: '.html' %}
    {% capture img_exists %}{% file_exists {{ filename }}.png %}{% endcapture %}

    {% if img_exists == "true" %}
        <img src="images/reference_designs/{{ filename }}.png">
    {% endif %}
{% endif %}