Fixes #5446 Improve Description Metatag defaults.

[tadean]

Description

This PR adds a new token, node:az-automatic-summary that computes a generated summary uising the naive TextRank algorithm. This is a deterministic algorithm selects sentences that are computed by graph scoring to be the most significant.

Release notes

An az-automatic-summary token has been added that computes content summaries. This is used for summaries when a description is not specified by the editor.

Related issues

#5446

How to test

• Create page content
• Inspect resulting description metatag

Types of changes

Arizona Quickstart (install profile, custom modules, custom theme)

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Drupal core

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  • Security update
  • Patch level release (non-security bug-fix release)
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  • Major or minor level update
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Drupal contrib projects

• Patch release changes
  • Security update
  • Patch or minor level update
  • Add new module
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• Minor release changes
  • Major level update
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  • Other or unknown

Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.
• My change requires release notes.

[tadean]

Todo:

• Improve tokenization so that tags that end without punctuation (such as headers) do not run-on into the following sentence. This leads to headers being considered part of the sentence that comes after. Lack of this currently causes some odd summaries.
• Prefer summary field where possible - this is deliberately not done right now so that the computed summaries can be seen
• Do not select low-scoring sentences even if it is the "best" sentence
• Langcode-based stopword handling
• Allow several sentences in summary, as long as they are high-schoring.

[tadean]

<meta property="og:description" content="Wilbur Wildcat&#039;s book review on The Life of Leonardo da Vinci, exploring the Renaissance master&#039;s boundless creativity and curiosity." />