Using filters in tags

[drekka]

I want to be able to use a filter inside a {% if expression %}. I've tried all sorts of things but cannot figure out if it's possible. Here is what I've tried:

{% if page.content | number_of_words > 200 %}
   ...
{% endif %}

Have I got the syntax wrong? or is this supported? or is there a bug?

[mhw]

Can you use the capture tag to put the output of the filter chain into a variable? Something like this:

{% capture word_count %}{{ page.content | number_of_words }}{% endcapture %}
{% if word_count > 200 %}
   ...
{% endif %}

[drekka]

I tried that, but it saved the rsult as a string so the if statement could not do the comparison. Is there something I can do to get liquid to see a string as a number?

[mhw]

Hmm; it doesn't look like it, at least not using that kind of syntax and approach. As you say, capture always assigns a string to the variable, so that won't work, and the if tag doesn't support filters so the original syntax you suggest won't work either.

A kludge that might work would be to define a filter called something like gt that worked along the lines of the existing plus and minus filters, then you should be able to do something like:

{% capture too_long %}{{ page.content | number_of_words | gt: 200 }}{% endcapture %}
{% if  too_long == "true" %}
   ...
{% endif %}

Slightly less of a kludge might be to add a content_word_count method to the page drop, if you can.

Another option is the following hack:

{% capture truncated %}{{ page.content | truncatewords: 200, '' }}{% endcapture %}
{% if truncated != page.content %}
   ...
{% endif %}

I agree, though, that it would be useful if the syntax was a bit more flexible and didn't require these hacks.

[drekka]

Thanks, I'll give those a try. I agree that they are "kludgy". I cannot modify or define anything because this is all being uploaded to github and they control jekyll, not me. :-(

I don't know if it's practical or not, but having tags be able to run embedded filters or at least have capture set a type appropriate to the return value would be really useful.