Application Helpers

Format Helpers

Format helpers are several useful utilities for manipulating the format of text to achieve a goal. The four format helpers are escape_html, distance_of_time_in_words, time_ago_in_words, and js_escape_html.

The escape_html and js_escape_html function are for taking an html string and escaping certain characters. escape_html will escape ampersands, brackets and quotes to their HTML/XML entities. This is useful to sanitize user content before displaying this on a template. js_escape_html is used for passing javascript information from a js template to a javascript function.

escape_html('<hello>&<goodbye>') # => &lt;hello&gt;&amp;&lt;goodbye&gt;

There is also an alias for escape_html called h for even easier usage within templates.

Format helpers also includes a number of useful text manipulation functions such as simple_format, pluralize, word_wrap, and truncate.

simple_format("hello\nworld") # => "<p>hello<br/>world</p>"
pluralize(2, 'person') => '2 people'
word_wrap('Once upon a time', :line_width => 8) => "Once upon\na time"
truncate("Once upon a time in a world far far away", :length => 8) => "Once upon..."
truncate_words("Once upon a time in a world far far away", :length => 4) => "Once upon a time..."
highlight('Lorem dolor sit', 'dolor') => "Lorem <strong class="highlight">dolor</strong> sit"

These helpers can be invoked from any route or view within your application.

List of Format Helpers

• simple_format(text, html_options)
  • Returns text transformed into HTML using simple formatting rules.
  • simple_format("hello\nworld") => "<p>hello<br/>world</p>"
• pluralize(count, singular, plural = nil)
  • Attempts to pluralize the singular word unless count is 1.
  • pluralize(2, 'person') => '2 people'
• word_wrap(text, *args)
  • Wraps the text into lines no longer than line_width width.
  • word_wrap('Once upon a time', :line_width => 8) => "Once upon\na time"
• truncate(text, *args)
  • Truncates a given text after a given :length if text is longer than :length (defaults to 30).
  • truncate("Once upon a time in a world far far away", :length => 8) => "Once upon..."
• truncate_words(text, *args)
  • Truncates a given text after a given :length of total words (defaults to 30).
  • truncate_words("Once upon a time in a world far far away", :length => 4) => "Once upon a time..."
• highlight(text, words, *args)
  • Highlights one or more words everywhere in text by inserting it into a :highlighter string.
  • highlight('Lorem ipsum dolor sit amet', 'dolor')
• escape_html (alias h and h!)
  • (from RackUtils) Escape ampersands, brackets and quotes to their HTML/XML entities.
• strip_tags(html)
  • Remove all html tags and return only a clean text.
• distance_of_time_in_words(from_time, to_time = 0)
  • Returns relative time in words referencing the given date
  • distance_of_time_in_words(2.days.ago) => "2 days"
  • distance_of_time_in_words(5.minutes.ago) => "5 minutes"
  • distance_of_time_in_words(2800.days.ago) => "over 7 years"
• time_ago_in_words(from_time)
  • Returns relative time in words from the current date
  • time_ago_in_words(2.days.ago) => "2 days"
  • time_ago_in_words(1.day.from_now) => "tomorrow"
• js_escape_html(html_content)
  • Escapes html to allow passing information to javascript. Used for passing data inside an ajax .js.erb template.
  • js_escape_html("<h1>Hey</h1>")

last updated: 2022-02-22