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rails--rails/actionview/lib/action_view/helpers/text_helper.rb
2013-06-20 17:23:15 +02:00

442 lines
17 KiB
Ruby

require 'active_support/core_ext/string/filters'
require 'active_support/core_ext/array/extract_options'
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('<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>&lt;a href=\"http://example.com/\"&gt;Example&lt;/a&gt;</p>"
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.
#
# <%
# 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 <tt>:length</tt> if +text+ is longer than <tt>:length</tt>
# (defaults to 30). The last characters will be replaced with the <tt>:omission</tt> (defaults to "...")
# for a total length not exceeding <tt>:length</tt>.
#
# Pass a <tt>:separator</tt> to truncate +text+ at a natural break.
#
# Pass a block if you want to show extra content when the text is truncated.
#
# The result is marked as HTML-safe, but it is escaped by default, unless <tt>:escape</tt> is
# +false+. Care should be taken if +text+ contains HTML tags or entities, because truncation
# may produce invalid HTML (such as unbalanced or incomplete tags).
#
# 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("Once upon a time in a world far far away") { link_to "Continue", "#" }
# # => "Once upon a time in a wo...<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 one or more +phrases+ everywhere in +text+ by inserting it into
# a <tt>:highlighter</tt> string. The highlighter can be specialized by passing <tt>:highlighter</tt>
# as a single-quoted string with <tt>\1</tt> where the phrase is to be inserted (defaults to
# '<mark>\1</mark>')
#
# highlight('You searched for: rails', 'rails')
# # => You searched for: <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>
def highlight(text, phrases, options = {})
text = sanitize(text) if options.fetch(:sanitize, true)
if text.blank? || phrases.blank?
text
else
highlighter = options.fetch(:highlighter, '<mark>\1</mark>')
match = Array(phrases).map { |p| Regexp.escape(p) }.join('|')
text.gsub(/(#{match})(?![^<]*?>)/i, highlighter)
end.html_safe
end
# Extracts an excerpt from +text+ that matches the first instance of +phrase+.
# The <tt>:radius</tt> option expands the excerpt on each side of the first occurrence of +phrase+ by the number of characters
# defined in <tt>:radius</tt> (which defaults to 100). If the excerpt radius overflows the beginning or end of the +text+,
# then the <tt>:omission</tt> option (which defaults to "...") will be prepended/appended accordingly. Use the
# <tt>:separator</tt> option to choose the delimitation. The resulting string will be stripped in any case. If the +phrase+
# isn't found, nil is returned.
#
# 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, "")
phrase = Regexp.escape(phrase)
regex = /#{phrase}/i
return unless matches = text.match(regex)
phrase = matches[0]
text.split(separator).each do |value|
if value.match(regex)
regex = phrase = value
break
end
end
first_part, second_part = text.split(regex, 2)
prefix, first_part = cut_excerpt_part(:first, first_part, separator, options)
postfix, second_part = cut_excerpt_part(:second, second_part, separator, options)
prefix + (first_part + separator + phrase + separator + second_part).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.
#
# 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)
word = if (count == 1 || count =~ /^1(\.0+)?$/)
singular
else
plural || singular.pluralize
end
"#{count || 0} #{word}"
end
# Wraps the +text+ into lines no longer than +line_width+ width. This method
# breaks on the first whitespace character that does not exceed +line_width+
# (which is 80 by default).
#
# word_wrap('Once upon a time')
# # => Once upon a time
#
# word_wrap('Once upon a time, in a kingdom called Far Far Away, a king fell ill, and finding a successor to the throne turned out to be more trouble than anyone could have imagined...')
# # => Once upon a time, in a kingdom called Far Far Away, a king fell ill, and finding\na successor to the throne turned out to be more trouble than anyone could have\nimagined...
#
# word_wrap('Once upon a time', line_width: 8)
# # => Once\nupon a\ntime
#
# word_wrap('Once upon a time', line_width: 1)
# # => Once\nupon\na\ntime
def word_wrap(text, options = {})
line_width = options.fetch(:line_width, 80)
text.split("\n").collect do |line|
line.length > line_width ? line.gsub(/(.{1,#{line_width}})(\s+|$)/, "\\1\n").strip : line
end * "\n"
end
# Returns +text+ transformed into HTML using simple formatting rules.
# Two or more consecutive newlines(<tt>\n\n</tt>) are considered as a
# paragraph and wrapped in <tt><p></tt> tags. One newline (<tt>\n</tt>) is
# considered as 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>: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!</span> It's true.</p>"
def simple_format(text, html_options = {}, options = {})
wrapper_tag = options.fetch(:wrapper_tag, :p)
text = sanitize(text) 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, paragraph, html_options, options[:sanitize])
}.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 = 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| %>
# <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
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
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, "...")
part = part.split(separator)
part.delete("")
affix = part.size > radius ? omission : ""
part = if part_position == :first
drop_index = [part.length - radius, 0].max
part.drop(drop_index)
else
part.first(radius)
end
return affix, part.join(separator)
end
end
end
end