require 'active_support/core_ext/object/blank'
require 'active_support/core_ext/string/filters'
module ActionView
# = Action View Text Helpers
module Helpers #:nodoc:
# The TextHelper module provides a set of methods for filtering, formatting
# and transforming strings, which can reduce the amount of inline Ruby code in
# your views. These helper methods extend Action View making them callable
# within your template files.
#
# ==== Sanitization
#
# Most text helpers by default sanitize the given content, but do not escape it.
# This means HTML tags will appear in the page but all malicious code will be removed.
# Let's look at some examples using the +simple_format+ method:
#
# simple_format('Example')
# # => "Example
"
#
# simple_format('Example')
# # => "Example
"
#
# If you want to escape all content, you should invoke the +h+ method before
# calling the text helper.
#
# simple_format h('Example')
# # => "<a href=\"http://example.com/\">Example</a>
"
module TextHelper
extend ActiveSupport::Concern
include SanitizeHelper
include TagHelper
# The preferred method of outputting text in your views is to use the
# <%= "text" %> eRuby syntax. The regular _puts_ and _print_ methods
# do not operate as expected in an eRuby code block. If you absolutely must
# output text within a non-output code block (i.e., <% %>), you can use the concat method.
#
# ==== Examples
# <%
# concat "hello"
# # is the equivalent of <%= "hello" %>
#
# if logged_in
# concat "Logged in!"
# else
# concat link_to('login', :action => login)
# end
# # will either display "Logged in!" or a login link
# %>
def concat(string)
output_buffer << string
end
def safe_concat(string)
output_buffer.respond_to?(:safe_concat) ? output_buffer.safe_concat(string) : concat(string)
end
# Truncates a given +text+ after a given :length if +text+ is longer than :length
# (defaults to 30). The last characters will be replaced with the :omission (defaults to "...")
# for a total length not exceeding :length.
#
# Pass a :separator to truncate +text+ at a natural break.
#
# The result is not marked as HTML-safe, so will be subject to the default escaping when
# used in views, unless wrapped by raw(). Care should be taken if +text+ contains HTML tags
# or entities, because truncation may produce invalid HTML (such as unbalanced or incomplete tags).
#
# ==== Examples
#
# truncate("Once upon a time in a world far far away")
# # => "Once upon a time in a world..."
#
# truncate("Once upon a time in a world far far away", :length => 17)
# # => "Once upon a ti..."
#
# truncate("Once upon a time in a world far far away", :length => 17, :separator => ' ')
# # => "Once upon a..."
#
# truncate("And they found that many people were sleeping better.", :length => 25, :omission => '... (continued)')
# # => "And they f... (continued)"
#
# truncate("Once upon a time in a world far far away
")
# # => "Once upon a time in a wo..."
def truncate(text, options = {})
options.reverse_merge!(:length => 30)
text.truncate(options.delete(:length), options) if text
end
# Highlights one or more +phrases+ everywhere in +text+ by inserting it into
# a :highlighter string. The highlighter can be specialized by passing :highlighter
# as a single-quoted string with \1 where the phrase is to be inserted (defaults to
# '\1')
#
# ==== Examples
# highlight('You searched for: rails', 'rails')
# # => You searched for: rails
#
# highlight('You searched for: ruby, rails, dhh', 'actionpack')
# # => You searched for: ruby, rails, dhh
#
# highlight('You searched for: rails', ['for', 'rails'], :highlighter => '\1')
# # => You searched for: rails
#
# highlight('You searched for: rails', 'rails', :highlighter => '\1')
# # => You searched for: rails
#
# You can still use highlight with the old API that accepts the
# +highlighter+ as its optional third parameter:
# highlight('You searched for: rails', 'rails', '\1') # => You searched for: rails
def highlight(text, phrases, *args)
options = args.extract_options!
unless args.empty?
options[:highlighter] = args[0] || '\1'
end
options.reverse_merge!(:highlighter => '\1')
text = sanitize(text) unless options[:sanitize] == false
if text.blank? || phrases.blank?
text
else
match = Array(phrases).map { |p| Regexp.escape(p) }.join('|')
text.gsub(/(#{match})(?![^<]*?>)/i, options[:highlighter])
end.html_safe
end
# Extracts an excerpt from +text+ that matches the first instance of +phrase+.
# The :radius option 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 :omission option (which defaults to "...") 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', :radius => 5)
# # => ...s is an exam...
#
# excerpt('This is an example', 'is', :radius => 5)
# # => This is a...
#
# excerpt('This is an example', 'is')
# # => This is an example
#
# excerpt('This next thing is an example', 'ex', :radius => 2)
# # => ...next...
#
# excerpt('This is also an example', 'an', :radius => 8, :omission => ' ')
# # => is also an example
#
# You can still use excerpt with the old API that accepts the
# +radius+ as its optional third and the +ellipsis+ as its
# optional forth parameter:
# excerpt('This is an example', 'an', 5) # => ...s is an exam...
# excerpt('This is also an example', 'an', 8, ' ') # => is also an example
def excerpt(text, phrase, *args)
return unless text && phrase
options = args.extract_options!
unless args.empty?
options[:radius] = args[0] || 100
options[:omission] = args[1] || "..."
end
options.reverse_merge!(:radius => 100, :omission => "...")
phrase = Regexp.escape(phrase)
return unless found_pos = text =~ /(#{phrase})/i
start_pos = [ found_pos - options[:radius], 0 ].max
end_pos = [ [ found_pos + phrase.length + options[:radius] - 1, 0].max, text.length ].min
prefix = start_pos > 0 ? options[:omission] : ""
postfix = end_pos < text.length - 1 ? options[:omission] : ""
prefix + text[start_pos..end_pos].strip + postfix
end
# Attempts to pluralize the +singular+ word unless +count+ is 1. If
# +plural+ is supplied, it will use that when count is > 1, otherwise
# it will use the Inflector to determine the plural form
#
# ==== Examples
# pluralize(1, 'person')
# # => 1 person
#
# pluralize(2, 'person')
# # => 2 people
#
# pluralize(3, 'person', 'users')
# # => 3 users
#
# pluralize(0, 'person')
# # => 0 people
def pluralize(count, singular, plural = nil)
"#{count || 0} " + ((count == 1 || count =~ /^1(\.0+)?$/) ? singular : (plural || singular.pluralize))
end
# Wraps the +text+ into lines no longer than +line_width+ width. This method
# breaks on the first whitespace character that does not exceed +line_width+
# (which is 80 by default).
#
# ==== Examples
#
# word_wrap('Once upon a time')
# # => Once upon a time
#
# word_wrap('Once upon a time, in a kingdom called Far Far Away, a king fell ill, and finding a successor to the throne turned out to be more trouble than anyone could have imagined...')
# # => Once upon a time, in a kingdom called Far Far Away, a king fell ill, and finding\n a successor to the throne turned out to be more trouble than anyone could have\n imagined...
#
# word_wrap('Once upon a time', :line_width => 8)
# # => Once upon\na time
#
# word_wrap('Once upon a time', :line_width => 1)
# # => Once\nupon\na\ntime
#
# You can still use word_wrap with the old API that accepts the
# +line_width+ as its optional second parameter:
# word_wrap('Once upon a time', 8) # => Once upon\na time
def word_wrap(text, *args)
options = args.extract_options!
unless args.blank?
options[:line_width] = args[0] || 80
end
options.reverse_merge!(:line_width => 80)
text.split("\n").collect do |line|
line.length > options[:line_width] ? line.gsub(/(.{1,#{options[:line_width]}})(\s+|$)/, "\\1\n").strip : line
end * "\n"
end
# Returns +text+ transformed into HTML using simple formatting rules.
# Two or more consecutive newlines(\n\n) are considered as a
# paragraph and wrapped in tags. One newline (\n) is
# considered as a linebreak and a
tag is appended. This
# method does not remove the newlines from the +text+.
#
# You can pass any HTML attributes into html_options. These
# will be added to all created paragraphs.
#
# ==== Options
# * :sanitize - If +false+, does not sanitize +text+.
#
# ==== Examples
# my_text = "Here is some basic text...\n...with a line break."
#
# simple_format(my_text)
# # => "
Here is some basic text...\n
...with a line break.
"
#
# more_text = "We want to put a paragraph...\n\n...right there."
#
# simple_format(more_text)
# # => "We want to put a paragraph...
\n\n...right there.
"
#
# simple_format("Look ma! A class!", :class => 'description')
# # => "Look ma! A class!
"
#
# simple_format("I'm allowed! It's true.", {}, :sanitize => false)
# # => "I'm allowed! It's true.
"
def simple_format(text, html_options={}, options={})
text = '' if text.nil?
text = text.dup
start_tag = tag('p', html_options, true)
text = sanitize(text) unless options[:sanitize] == false
text = text.to_str
text.gsub!(/\r\n?/, "\n") # \r\n and \r -> \n
text.gsub!(/\n\n+/, "
\n\n#{start_tag}") # 2+ newline -> paragraph
text.gsub!(/([^\n]\n)(?=[^\n])/, '\1
') # 1 newline -> br
text.insert 0, start_tag
text.html_safe.safe_concat("")
end
# Creates a Cycle object whose _to_s_ method cycles through elements of an
# array every time it is called. This can be used for example, to alternate
# classes for table rows. You can use named cycles to allow nesting in loops.
# Passing a Hash as the last parameter with a :name key will create a
# named cycle. The default name for a cycle without a +:name+ key is
# "default". You can manually reset a cycle by calling reset_cycle
# and passing the name of the cycle. The current cycle string can be obtained
# anytime using the current_cycle method.
#
# ==== Examples
# # Alternate CSS classes for even and odd numbers...
# @items = [1,2,3,4]
#
# <% @items.each do |item| %>
# ">
# | item |
#
# <% end %>
#
#
#
# # Cycle CSS classes for rows, and text colors for values within each row
# @items = x = [{:first => 'Robert', :middle => 'Daniel', :last => 'James'},
# {:first => 'Emily', :middle => 'Shannon', :maiden => 'Pike', :last => 'Hicks'},
# {:first => 'June', :middle => 'Dae', :last => 'Jones'}]
# <% @items.each do |item| %>
# "row_class") -%>">
# |
# <% item.values.each do |value| %>
# <%# Create a named cycle "colors" %>
# "colors") -%>">
# <%= value %>
#
# <% end %>
# <% reset_cycle("colors") %>
# |
#
# <% end %>
def cycle(first_value, *values)
if (values.last.instance_of? Hash)
params = values.pop
name = params[:name]
else
name = "default"
end
values.unshift(first_value)
cycle = get_cycle(name)
unless cycle && cycle.values == values
cycle = set_cycle(name, Cycle.new(*values))
end
cycle.to_s
end
# Returns the current cycle string after a cycle has been started. Useful
# for complex table highlighting or any other design need which requires
# the current cycle string in more than one place.
#
# ==== Example
# # Alternate background colors
# @items = [1,2,3,4]
# <% @items.each do |item| %>
# ">
# <%= item %>
#
# <% end %>
def current_cycle(name = "default")
cycle = get_cycle(name)
cycle.current_value if cycle
end
# Resets a cycle so that it starts from the first element the next time
# it is called. Pass in +name+ to reset a named cycle.
#
# ==== Example
# # Alternate CSS classes for even and odd numbers...
# @items = [[1,2,3,4], [5,6,3], [3,4,5,6,7,4]]
#
# <% @items.each do |item| %>
# ">
# <% item.each do |value| %>
# "colors") -%>">
# <%= value %>
#
# <% end %>
#
# <% reset_cycle("colors") %>
#
# <% end %>
#
def reset_cycle(name = "default")
cycle = get_cycle(name)
cycle.reset if cycle
end
class Cycle #:nodoc:
attr_reader :values
def initialize(first_value, *values)
@values = values.unshift(first_value)
reset
end
def reset
@index = 0
end
def current_value
@values[previous_index].to_s
end
def to_s
value = @values[@index].to_s
@index = next_index
return value
end
private
def next_index
step_index(1)
end
def previous_index
step_index(-1)
end
def step_index(n)
(@index + n) % @values.size
end
end
private
# The cycle helpers need to store the cycles in a place that is
# guaranteed to be reset every time a page is rendered, so it
# uses an instance variable of ActionView::Base.
def get_cycle(name)
@_cycles = Hash.new unless defined?(@_cycles)
return @_cycles[name]
end
def set_cycle(name, cycle_object)
@_cycles = Hash.new unless defined?(@_cycles)
@_cycles[name] = cycle_object
end
end
end
end