Word count and reading time estimation for GROQ and Portable Text

Make a rough calculation of word count and reading time for your Portable Text fields

GROQ query

*[
  _type == "post"
]{
  title,
  "numberOfCharacters": length(pt::text(body)),
  // assumes 5 characters as mean word length
  // https://ux.stackexchange.com/questions/22520/how-long-does-it-take-to-read-x-number-of-characters
  "estimatedWordCount": round(length(pt::text(body)) / 5),
  // Words per minute: 180
  "estimatedReadingTime": round(length(pt::text(body)) / 5 / 180 )
}

Advanced GROQ query

{
  "wpm": 180,
  "meanWordCharacterCount": 5
}
{  
  "posts": *[_type == "post"]
  	{
  		...,
		  "numberOfCharacters": length(pt::text(body))
		}
		{	
      title,
  	  "estimatedWordCount": round(numberOfCharacters / ^.^.meanWordCharacterCount),
  		"estimatedReadingTime": round(numberOfCharacters / ^.^.meanWordCharacterCount / ^.^.wpm)
		}
}

It's possible to estimate word count and reading time for Portable Text fields using GROQ. You need to make some assumptions about the mean character count for words, and words per minute. Because pt::text() currently only supports top-level block fields, custom blocks aren't included in this estimation.

You can also do a trick where you chain projections in order to set the constants at the top of the query to reuse them. Remember to use the parent hat operator (^).

The algorithm is borrowed from this discussion on Stack Exchange.