Quick Tip: Invoking Liquid Tags from Custom Filters

I was recently working on a Jekyll website and figured out a neat trick involving custom filters. I was creating a filter to extend the functionality of the Jekyll link tag to specially handle certain site-specific URLs and delegate to the link tag in all other cases.

The tricky part of writing this filter was delegating to the link tag from Ruby, as Liquid tags normally must be put in your markup. However, using the code below I was able to do it. (Just replace <TAG> with your tag of choice, in my case Link, and replace <INPUT> with the input to the tag.)

Jekyll::Tags::<TAG>.send(
    :new,
    Jekyll::Tags::<TAG>.tag_name,
    <INPUT>,
    Liquid::ParseContext.new
).render(@context)

Using this trick, I was able to successfully write the filter I needed.

While Shopify has pretty good documentation for creating custom filters and custom tags, this trick wasn’t mentioned so I thought I’d share it here.

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