actionview/lib/action_view/helpers/text_helper.rb
# frozen_string_literal: true
require "active_support/core_ext/string/filters"
require "active_support/core_ext/string/access"
require "active_support/core_ext/array/extract_options"
require "action_view/helpers/sanitize_helper"
require "action_view/helpers/tag_helper"
require "action_view/helpers/output_safety_helper"
module ActionView
module Helpers # :nodoc:
# = Action View Text \Helpers
#
# 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 that generate HTML output sanitize the given input by default,
# 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('<a href="http://example.com/">Example</a>')
# # => "<p><a href=\"http://example.com/\">Example</a></p>"
#
# simple_format('<a href="javascript:alert(\'no!\')">Example</a>')
# # => "<p><a>Example</a></p>"
#
# If you want to escape all content, you should invoke the +h+ method before
# calling the text helper.
#
# simple_format h('<a href="http://example.com/">Example</a>')
# # => "<p><a href=\"http://example.com/\">Example</a></p>"
module TextHelper
extend ActiveSupport::Concern
include SanitizeHelper
include TagHelper
include OutputSafetyHelper
# The preferred method of outputting text in your views is to use the
# <tt><%= "text" %></tt> 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., <tt><% %></tt>), you
# can use the +concat+ method.
#
# <% concat "hello" %> is equivalent to <%= "hello" %>
#
# <%
# unless signed_in?
# concat link_to("Sign In", action: :sign_in)
# end
# %>
#
# is equivalent to
#
# <% unless signed_in? %>
# <%= link_to "Sign In", action: :sign_in %>
# <% end %>
#
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 +text+ if it is longer than a specified +:length+. If +text+
# is truncated, an omission marker will be appended to the result for a
# total length not exceeding +:length+.
#
# You can also pass a block to render and append extra content after the
# omission marker when +text+ is truncated. However, this content _can_
# cause the total length to exceed +:length+ characters.
#
# The result will be escaped unless <tt>escape: false</tt> is specified.
# In any case, the result will be marked HTML-safe. Care should be taken
# if +text+ might contain HTML tags or entities, because truncation could
# produce invalid HTML, such as unbalanced or incomplete tags.
#
# ==== Options
#
# [+:length+]
# The maximum number of characters that should be returned, excluding
# any extra content from the block. Defaults to 30.
#
# [+:omission+]
# The string to append after truncating. Defaults to <tt>"..."</tt>.
#
# [+:separator+]
# A string or regexp used to find a breaking point at which to truncate.
# By default, truncation can occur at any character in +text+.
#
# [+:escape+]
# Whether to escape the result. Defaults to true.
#
# ==== 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("<p>Once upon a time in a world far far away</p>")
# # => "<p>Once upon a time in a wo..."
#
# truncate("<p>Once upon a time in a world far far away</p>", escape: false)
# # => "<p>Once upon a time in a wo..."
#
# truncate("Once upon a time in a world far far away") { link_to "Continue", "#" }
# # => "Once upon a time in a world...<a href=\"#\">Continue</a>"
def truncate(text, options = {}, &block)
if text
length = options.fetch(:length, 30)
content = text.truncate(length, options)
content = options[:escape] == false ? content.html_safe : ERB::Util.html_escape(content)
content << capture(&block) if block_given? && text.length > length
content
end
end
# Highlights occurrences of +phrases+ in +text+ by formatting them with a
# highlighter string. +phrases+ can be one or more strings or regular
# expressions. The result will be marked HTML safe. By default, +text+ is
# sanitized before highlighting to prevent possible XSS attacks.
#
# If a block is specified, it will be used instead of the highlighter
# string. Each occurrence of a phrase will be passed to the block, and its
# return value will be inserted into the final result.
#
# ==== Options
#
# [+:highlighter+]
# The highlighter string. Uses <tt>\1</tt> as the placeholder for a
# phrase, similar to +String#sub+. Defaults to <tt>"<mark>\1</mark>"</tt>.
# This option is ignored if a block is specified.
#
# [+:sanitize+]
# Whether to sanitize +text+ before highlighting. Defaults to true.
#
# ==== Examples
#
# highlight('You searched for: rails', 'rails')
# # => "You searched for: <mark>rails</mark>"
#
# highlight('You searched for: rails', /for|rails/)
# # => "You searched <mark>for</mark>: <mark>rails</mark>"
#
# highlight('You searched for: ruby, rails, dhh', 'actionpack')
# # => "You searched for: ruby, rails, dhh"
#
# highlight('You searched for: rails', ['for', 'rails'], highlighter: '<em>\1</em>')
# # => "You searched <em>for</em>: <em>rails</em>"
#
# highlight('You searched for: rails', 'rails', highlighter: '<a href="search?q=\1">\1</a>')
# # => "You searched for: <a href=\"search?q=rails\">rails</a>"
#
# highlight('You searched for: rails', 'rails') { |match| link_to(search_path(q: match, match)) }
# # => "You searched for: <a href=\"search?q=rails\">rails</a>"
#
# highlight('<a href="javascript:alert(\'no!\')">ruby</a> on rails', 'rails', sanitize: false)
# # => "<a href=\"javascript:alert('no!')\">ruby</a> on <mark>rails</mark>"
def highlight(text, phrases, options = {}, &block)
text = sanitize(text) if options.fetch(:sanitize, true)
if text.blank? || phrases.blank?
text || ""
else
patterns = Array(phrases).map { |phrase| Regexp === phrase ? phrase : Regexp.escape(phrase) }
pattern = /(#{patterns.join("|")})/i
highlighter = options.fetch(:highlighter, '<mark>\1</mark>') unless block
text.scan(/<[^>]*|[^<]+/).each do |segment|
if !segment.start_with?("<")
if block
segment.gsub!(pattern, &block)
else
segment.gsub!(pattern, highlighter)
end
end
end.join
end.html_safe
end
# Extracts the first occurrence of +phrase+ plus surrounding text from
# +text+. An omission marker is prepended / appended if the start / end of
# the result does not coincide with the start / end of +text+. The result
# is always stripped in any case. Returns +nil+ if +phrase+ isn't found.
#
# ==== Options
#
# [+:radius+]
# The number of characters (or tokens — see +:separator+ option) around
# +phrase+ to include in the result. Defaults to 100.
#
# [+:omission+]
# The marker to prepend / append when the start / end of the excerpt
# does not coincide with the start / end of +text+. Defaults to
# <tt>"..."</tt>.
#
# [+:separator+]
# The separator between tokens to count for +:radius+. Defaults to
# <tt>""</tt>, which treats each character as a token.
#
# ==== 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: '<chop> ')
# # => "<chop> is also an example"
#
# excerpt('This is a very beautiful morning', 'very', separator: ' ', radius: 1)
# # => "...a very beautiful..."
def excerpt(text, phrase, options = {})
return unless text && phrase
separator = options.fetch(:separator, nil) || ""
case phrase
when Regexp
regex = phrase
else
regex = /#{Regexp.escape(phrase)}/i
end
return unless matches = text.match(regex)
phrase = matches[0]
unless separator.empty?
text.split(separator).each do |value|
if value.match?(regex)
phrase = value
break
end
end
end
first_part, second_part = text.split(phrase, 2)
prefix, first_part = cut_excerpt_part(:first, first_part, separator, options)
postfix, second_part = cut_excerpt_part(:second, second_part, separator, options)
affix = [first_part, separator, phrase, separator, second_part].join.strip
[prefix, affix, postfix].join
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 for the given locale,
# which defaults to +I18n.locale+.
#
# The word will be pluralized using rules defined for the locale
# (you must define your own inflection rules for languages other than English).
# See ActiveSupport::Inflector.pluralize
#
# pluralize(1, 'person')
# # => "1 person"
#
# pluralize(2, 'person')
# # => "2 people"
#
# pluralize(3, 'person', plural: 'users')
# # => "3 users"
#
# pluralize(0, 'person')
# # => "0 people"
#
# pluralize(2, 'Person', locale: :de)
# # => "2 Personen"
def pluralize(count, singular, plural_arg = nil, plural: plural_arg, locale: I18n.locale)
word = if count == 1 || count.to_s.match?(/^1(\.0+)?$/)
singular
else
plural || singular.pluralize(locale)
end
"#{count || 0} #{word}"
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).
#
# 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\na successor to the throne turned out to be more trouble than anyone could have\nimagined..."
#
# word_wrap('Once upon a time', line_width: 8)
# # => "Once\nupon a\ntime"
#
# word_wrap('Once upon a time', line_width: 1)
# # => "Once\nupon\na\ntime"
#
# You can also specify a custom +break_sequence+ ("\n" by default):
#
# word_wrap('Once upon a time', line_width: 1, break_sequence: "\r\n")
# # => "Once\r\nupon\r\na\r\ntime"
def word_wrap(text, line_width: 80, break_sequence: "\n")
return +"" if text.empty?
# Match up to `line_width` characters, followed by one of
# (1) non-newline whitespace plus an optional newline
# (2) the end of the string, ignoring any trailing newlines
# (3) a newline
#
# -OR-
#
# Match an empty line
pattern = /(.{1,#{line_width}})(?:[^\S\n]+\n?|\n*\Z|\n)|\n/
text.gsub(pattern, "\\1#{break_sequence}").chomp!(break_sequence)
end
# Returns +text+ transformed into HTML using simple formatting rules.
# Two or more consecutive newlines (<tt>\n\n</tt> or <tt>\r\n\r\n</tt>) are
# considered a paragraph and wrapped in <tt><p></tt> tags. One newline
# (<tt>\n</tt> or <tt>\r\n</tt>) is considered a linebreak and a
# <tt><br /></tt> tag is appended. This method does not remove the
# newlines from the +text+.
#
# You can pass any HTML attributes into <tt>html_options</tt>. These
# will be added to all created paragraphs.
#
# ==== Options
# * <tt>:sanitize</tt> - If +false+, does not sanitize +text+.
# * <tt>:sanitize_options</tt> - Any extra options you want appended to the sanitize.
# * <tt>:wrapper_tag</tt> - String representing the wrapper tag, defaults to <tt>"p"</tt>
#
# ==== Examples
# my_text = "Here is some basic text...\n...with a line break."
#
# simple_format(my_text)
# # => "<p>Here is some basic text...\n<br />...with a line break.</p>"
#
# simple_format(my_text, {}, wrapper_tag: "div")
# # => "<div>Here is some basic text...\n<br />...with a line break.</div>"
#
# more_text = "We want to put a paragraph...\n\n...right there."
#
# simple_format(more_text)
# # => "<p>We want to put a paragraph...</p>\n\n<p>...right there.</p>"
#
# simple_format("Look ma! A class!", class: 'description')
# # => "<p class='description'>Look ma! A class!</p>"
#
# simple_format("<blink>Unblinkable.</blink>")
# # => "<p>Unblinkable.</p>"
#
# simple_format("<blink>Blinkable!</blink> It's true.", {}, sanitize: false)
# # => "<p><blink>Blinkable!</blink> It's true.</p>"
#
# simple_format("<a target=\"_blank\" href=\"http://example.com\">Continue</a>", {}, { sanitize_options: { attributes: %w[target href] } })
# # => "<p><a target=\"_blank\" href=\"http://example.com\">Continue</a></p>"
def simple_format(text, html_options = {}, options = {})
wrapper_tag = options[:wrapper_tag] || "p"
text = sanitize(text, options.fetch(:sanitize_options, {})) if options.fetch(:sanitize, true)
paragraphs = split_paragraphs(text)
if paragraphs.empty?
content_tag(wrapper_tag, nil, html_options)
else
paragraphs.map! { |paragraph|
content_tag(wrapper_tag, raw(paragraph), html_options)
}.join("\n\n").html_safe
end
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 <tt>:name</tt> key will create a
# named cycle. The default name for a cycle without a +:name+ key is
# <tt>"default"</tt>. 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.
#
# <%# Alternate CSS classes for even and odd numbers... %>
# <% @items = [1,2,3,4] %>
# <table>
# <% @items.each do |item| %>
# <tr class="<%= cycle("odd", "even") -%>">
# <td><%= item %></td>
# </tr>
# <% end %>
# </table>
#
#
# <%# Cycle CSS classes for rows, and text colors for values within each row %>
# <% @items = [
# { first: "Robert", middle: "Daniel", last: "James" },
# { first: "Emily", middle: "Shannon", maiden: "Pike", last: "Hicks" },
# { first: "June", middle: "Dae", last: "Jones" },
# ] %>
# <% @items.each do |item| %>
# <tr class="<%= cycle("odd", "even", name: "row_class") -%>">
# <td>
# <% item.values.each do |value| %>
# <%# Create a named cycle "colors" %>
# <span style="color:<%= cycle("red", "green", "blue", name: "colors") -%>">
# <%= value %>
# </span>
# <% end %>
# <% reset_cycle("colors") %>
# </td>
# </tr>
# <% end %>
def cycle(first_value, *values)
options = values.extract_options!
name = options.fetch(:name, "default")
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.
#
# <%# Alternate background colors %>
# <% @items = [1,2,3,4] %>
# <% @items.each do |item| %>
# <div style="background-color:<%= cycle("red","white","blue") %>">
# <span style="background-color:<%= current_cycle %>"><%= item %></span>
# </div>
# <% 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.
#
# <%# Alternate CSS classes for even and odd numbers... %>
# <% @items = [[1,2,3,4], [5,6,3], [3,4,5,6,7,4]] %>
# <table>
# <% @items.each do |item| %>
# <tr class="<%= cycle("even", "odd") -%>">
# <% item.each do |value| %>
# <span style="color:<%= cycle("#333", "#666", "#999", name: "colors") -%>">
# <%= value %>
# </span>
# <% end %>
#
# <% reset_cycle("colors") %>
# </tr>
# <% end %>
# </table>
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
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)
@_cycles[name]
end
def set_cycle(name, cycle_object)
@_cycles = Hash.new unless defined?(@_cycles)
@_cycles[name] = cycle_object
end
def split_paragraphs(text)
return [] if text.blank?
text.to_str.gsub(/\r\n?/, "\n").split(/\n\n+/).map! do |t|
t.gsub!(/([^\n]\n)(?=[^\n])/, '\1<br />') || t
end
end
def cut_excerpt_part(part_position, part, separator, options)
return "", "" unless part
radius = options.fetch(:radius, 100)
omission = options.fetch(:omission, "...")
if separator != ""
part = part.split(separator)
part.delete("")
end
affix = part.length > radius ? omission : ""
part =
if part_position == :first
part.last(radius)
else
part.first(radius)
end
if separator != ""
part = part.join(separator)
end
return affix, part
end
end
end
end