method

excerpt

v2.1.0 - Show latest stable - Class: ActionView::Helpers::TextHelper

excerpt(text, phrase, radius = 100, excerpt_string = "...")

public

Extracts an excerpt from text that matches the first instance of phrase. The radius expands the excerpt on each side of the first occurrence of phrase by the number of characters defined in radius (which defaults to 100). If the excerpt radius overflows the beginning or end of the text, then the excerpt_string will be prepended/appended accordingly. The resulting string will be stripped in any case. If the phrase isn’t found, nil is returned.

Examples

  excerpt('This is an example', 'an', 5)
  # => "...s is an exam..."

  excerpt('This is an example', 'is', 5)
  # => "This is a..."

  excerpt('This is an example', 'is')
  # => "This is an example"

  excerpt('This next thing is an example', 'ex', 2)
  # => "...next..."

  excerpt('This is also an example', 'an', 8, '<chop> ')
  # => "<chop> is also an example"

# File actionpack/lib/action_view/helpers/text_helper.rb, line 113
        def excerpt(text, phrase, radius = 100, excerpt_string = "...")
          if text && phrase
            phrase = Regexp.escape(phrase)

            if found_pos = text.chars =~ /(#{phrase})/i
              start_pos = [ found_pos - radius, 0 ].max
              end_pos   = [ [ found_pos + phrase.chars.length + radius - 1, 0].max, text.chars.length ].min

              prefix  = start_pos > 0 ? excerpt_string : ""
              postfix = end_pos < text.chars.length - 1 ? excerpt_string : ""

              prefix + text.chars[start_pos..end_pos].strip + postfix
            else
              nil
            end
          end
        end

1Note

Description copied from Rails 2.0

railsmonk · Sep 23, 20081 thank

Extracts an excerpt from text that matches the first instance of phrase. The radius expands the excerpt on each side of the first occurrence of phrase by the number of characters defined in radius (which defaults to 100). If the excerpt radius overflows the beginning or end of the text, then the excerpt_string will be prepended/appended accordingly. If the phrase isn‘t found, nil is returned.

==== Examples

excerpt('This is an example', 'an', 5)
# => "...s is an examp..."

excerpt('This is an example', 'is', 5)
# => "This is an..."

excerpt('This is an example', 'is')
# => "This is an example"

excerpt('This next thing is an example', 'ex', 2)
# => "...next t..."

excerpt('This is also an example', 'an', 8, '<chop> ')
# => "<chop> is also an example"

excerpt

Examples

1Note

Description copied from Rails 2.0

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