Truncate the description value to 100 words

[kemenaran]

Currently, on post pages, the value of the description, og: description, twitter: description and application/ld-json tags represent the whole text of the post.

Which means that the text of the post is included five times in the HTML document – adding to the page weight needlessly.

This commit ensures the description string is truncated to a sane value.

[y377]

@kemenaran If it can be customized according to the percentage, this should be the ultimate solution: for example, from 10% to 90% of the full text (if the description is defined in the preface), it is recommended to consider it!

[kemenaran]

@mattr- would you consider this improvement mergeable in the current state – or do you prefer to make it configurable?

[mattr-]

280 characters feels like a twitter specific limitation. Regardless of that, a blanket truncation at 280 characters doesn't take into account word or sentence endings, and it feels like we should do that before this PR is mergeable.

[kemenaran]

@mattr- thanks for your review! I updated the PR to:

• Limit the description length based on words count (instead of characters count);
• Make the maximum word count configurable (per page or site-wide).

I also added tests, and a new documentation section describing the behavior.

Does that look reasonable to you?

[kemenaran]

Yup, I just pushed fixes to the rubocop issues, it should be good now.

[mattr-]

Thanks for tackling this!

@jekyllbot: merge +minor

[kemenaran]

Great! Thanks for having a look into this, and for the maintenance work.

[y377]

@jekyllbot @kemenaran Thank you for your great efforts. Please tell me how to update the improved code. Because the plug-in has been installed before, no matter whether you use gem install jekyll-seo-tag or gem update jekyll-seo-tag, it will not help.

[mattr-]

You'll need to wait on a plugin release or tell bundler to fetch the code from the git repo in order to use this new feature.