Module: ActionView::Helpers::TextHelper
Relationships & Source Files | |
Extension / Inclusion / Inheritance Descendants | |
Included In:
::ActionView::Base,
::ActionView::Helpers,
FormHelper,
FormOptionsHelper,
FormTagHelper,
ActionView::Helpers::Tags::Base,
ActionView::Helpers::Tags::CheckBox,
ActionView::Helpers::Tags::CollectionCheckBoxes,
ActionView::Helpers::Tags::CollectionRadioButtons,
ActionView::Helpers::Tags::CollectionSelect,
ActionView::Helpers::Tags::ColorField,
ActionView::Helpers::Tags::DateField,
ActionView::Helpers::Tags::DateSelect,
ActionView::Helpers::Tags::DatetimeField,
ActionView::Helpers::Tags::DatetimeLocalField,
ActionView::Helpers::Tags::DatetimeSelect,
ActionView::Helpers::Tags::EmailField,
ActionView::Helpers::Tags::FileField,
ActionView::Helpers::Tags::GroupedCollectionSelect,
ActionView::Helpers::Tags::HiddenField,
ActionView::Helpers::Tags::Label,
ActionView::Helpers::Tags::MonthField,
ActionView::Helpers::Tags::NumberField,
ActionView::Helpers::Tags::PasswordField,
ActionView::Helpers::Tags::RadioButton,
ActionView::Helpers::Tags::RangeField,
ActionView::Helpers::Tags::SearchField,
ActionView::Helpers::Tags::Select,
ActionView::Helpers::Tags::TelField,
ActionView::Helpers::Tags::TextArea,
ActionView::Helpers::Tags::TextField,
ActionView::Helpers::Tags::TimeField,
ActionView::Helpers::Tags::TimeSelect,
ActionView::Helpers::Tags::TimeZoneSelect,
ActionView::Helpers::Tags::UrlField,
ActionView::Helpers::Tags::WeekField,
::ActionView::TestCase,
::ActionView::TestCase::Behavior
| |
Super Chains via Extension / Inclusion / Inheritance | |
Class Chain:
self,
::ActiveSupport::Concern
|
|
Instance Chain:
|
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Defined in: | actionview/lib/action_view/helpers/text_helper.rb |
Overview
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><a href=\"http://example.com/\">Example</a></p>"
Constant Summary
TagHelper - Included
Class Method Summary
::ActiveSupport::Concern - Extended
Instance Method Summary
-
#concat(string)
The preferred method of outputting text in your views is to use the <%= “text” %> eRuby syntax.
-
#current_cycle(name = "default")
Returns the current cycle string after a cycle has been started.
-
#cycle(first_value, *values)
Creates a Cycle object whose to_s method cycles through elements of an array every time it is called.
-
#excerpt(text, phrase, options = {})
Extracts an excerpt from
text
that matches the first instance ofphrase
. -
#highlight(text, phrases, options = {})
Highlights one or more
phrases
everywhere intext
by inserting it into a:highlighter
string. -
#pluralize(count, singular, plural = nil)
Attempts to pluralize the
singular
word unlesscount
is 1. -
#reset_cycle(name = "default")
Resets a cycle so that it starts from the first element the next time it is called.
- #safe_concat(string)
-
#simple_format(text, html_options = {}, options = {})
Returns
text
transformed into HTML using simple formatting rules. -
#truncate(text, options = {}, &block)
Truncates a given
text
after a given:length
iftext
is longer than:length
(defaults to 30). -
#word_wrap(text, options = {})
Wraps the
text
into lines no longer thanline_width
width.
TagHelper - Included
#cdata_section | Returns a CDATA section with the given |
#content_tag | Returns an HTML block tag of type |
#escape_once | Returns an escaped version of |
#tag | Returns an empty HTML tag of type |
CaptureHelper - Included
#capture | The capture method allows you to extract part of a template into a variable. |
#content_for | Calling content_for stores a block of markup in an identifier for later use. |
#content_for? | content_for? checks whether any content has been captured yet using |
#provide | The same as |
SanitizeHelper - Included
#sanitize | Sanitizes HTML input, stripping all tags and attributes that aren't whitelisted. |
#sanitize_css | Sanitizes a block of CSS code. |
#strip_links | Strips all link tags from |
#strip_tags | Strips all HTML tags from |
Instance Method Details
#concat(string)
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
%>
# File 'actionview/lib/action_view/helpers/text_helper.rb', line 52
def concat(string) output_buffer << string end
#current_cycle(name = "default")
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 %>
#cycle(first_value, *values)
Creates a TextHelper::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.
# 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 %>
#excerpt(text, phrase, options = {})
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. Use the :separator
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...
# File 'actionview/lib/action_view/helpers/text_helper.rb', line 168
def excerpt(text, phrase, = {}) return unless text && phrase separator = .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) 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, ) postfix, second_part = cut_excerpt_part(:second, second_part, separator, ) affix = [first_part, separator, phrase, separator, second_part].join.strip [prefix, affix, postfix].join end
#highlight(text, phrases, options = {})
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 '<mark>1</mark>') or passing a block that receives each matched term.
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>
# File 'actionview/lib/action_view/helpers/text_helper.rb', line 125
def highlight(text, phrases, = {}) text = sanitize(text) if .fetch(:sanitize, true) if text.blank? || phrases.blank? text || "" else match = Array(phrases).map do |p| Regexp === p ? p.to_s : Regexp.escape(p) end.join('|') if block_given? text.gsub(/(#{match})(?![^<]*?>)/i) { |found| yield found } else highlighter = .fetch(:highlighter, '<mark>\1</mark>') text.gsub(/(#{match})(?![^<]*?>)/i, highlighter) end end.html_safe end
#pluralize(count, singular, plural = nil)
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
# File 'actionview/lib/action_view/helpers/text_helper.rb', line 215
def pluralize(count, singular, plural = nil) word = if (count == 1 || count =~ /^1(\.0+)?$/) singular else plural || singular.pluralize end "#{count || 0} #{word}" end
#reset_cycle(name = "default")
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>
#safe_concat(string)
[ GitHub ]# File 'actionview/lib/action_view/helpers/text_helper.rb', line 56
def safe_concat(string) output_buffer.respond_to?(:safe_concat) ? output_buffer.safe_concat(string) : concat(string) end
#simple_format(text, html_options = {}, options = {})
Returns text
transformed into HTML using simple formatting rules. Two or more consecutive newlines(\n\n
) are considered as a paragraph and wrapped in <p>
tags. One newline (\n
) is considered as a linebreak and a <br />
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
- Iffalse
, does not sanitizetext
. -
:wrapper_tag
- ::String representing the wrapper tag, defaults to"p"
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>"
# File 'actionview/lib/action_view/helpers/text_helper.rb', line 283
def simple_format(text, = {}, = {}) wrapper_tag = .fetch(:wrapper_tag, :p) text = sanitize(text) if .fetch(:sanitize, true) paragraphs = split_paragraphs(text) if paragraphs.empty? content_tag(wrapper_tag, nil, ) else paragraphs.map! { |paragraph| content_tag(wrapper_tag, raw(paragraph), ) }.join("\n\n").html_safe end end
#truncate(text, options = {}, &block)
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.
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 :escape
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("<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 wo...<a href="#">Continue</a>"
# File 'actionview/lib/action_view/helpers/text_helper.rb', line 92
def truncate(text, = {}, &block) if text length = .fetch(:length, 30) content = text.truncate(length, ) content = [:escape] == false ? content.html_safe : ERB::Util.html_escape(content) content << capture(&block) if block_given? && text.length > length content end end
#word_wrap(text, options = {})
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
# File 'actionview/lib/action_view/helpers/text_helper.rb', line 240
def word_wrap(text, = {}) line_width = .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