Excerpt Highlighter

A PHP library for creating a highlighted excerpt a provided list of tokens in a provided text string.

Basic usage in an application

The included index.php file contains a generation form demo.

Make your code aware of the Highlighter class via your favorite method (e.g., use writecrow\Highlighter\HighlightExcerpt;)

print HighlightExcerpt::highlight('Round the rugged rock,' ['the']);
// Will print 'Round <mark>the</mark> rugged rock'

print HighlightExcerpt::highlight('Round the rugged rock,' ['the', 'rock']);
// Will print 'Round <mark>the</mark> rugged <mark>rock</mark>'

print HighlightExcerpt::highlight('Round the rugged rock,' ['ro', '"round"']);
// Will print 'Round the rugged rock', since `ro` is present, 
// but only a word partial,
// and `round` is present, but double-quotes indicate case-sensitivity
// so `round` != `Round`

Advanced behaviors

The excerpt highlighter will:

• Default to case-insensitive highlighting for a word (e.g., 'the')
• Become case-sensitive if the token is wrapped in double quotes (e.g. '"The"')
• Not highlight partial word matched (e.g., 'the' will not highlight therefore)
• Given multiple tokens passed to be highlighted, will create shorter, concatenated excerpts from the text which overall try to honor the length parameter specified (see below)
• Produce excerpts that start/end on word boundaries

Length

Pass a 3rd parameter, an integer, to the function to specify the desired length of the excerpt.

print HighlightExcerpt::highlight('Round the rugged rock,' ['the'], 300);
// Would limit the excerpt to 300 characters