module Haml::Helpers
This module contains various helpful methods to make it easier to do various tasks. {Haml::Helpers} is automatically included in the context that a Haml template is parsed in, so all these methods are at your disposal from within the template.
Constants
- HTML_ESCAPE
Characters that need to be escaped to HTML entities from user input
- HTML_ESCAPE_ONCE_REGEX
- HTML_ESCAPE_REGEX
Public Class Methods
@return [Boolean] Whether or not ActionView is loaded
# File lib/haml/helpers.rb, line 52 def self.action_view? @@action_view_defined end
Public Instance Methods
Captures the result of a block of Haml code, gets rid of the excess indentation, and returns it as a string. For example, after the following,
.foo - foo = capture_haml(13) do |a| %= a
the local variable `foo` would be assigned to `“<p>13</p>n”`.
@param args [Array] Arguments to pass into the block @yield [args] A block of Haml code that will be converted to a string @yieldparam args [Array] `args`
# File lib/haml/helpers.rb, line 362 def capture_haml(*args, &block) buffer = eval('if defined? _hamlout then _hamlout else nil end', block.binding) || haml_buffer with_haml_buffer(buffer) do position = haml_buffer.buffer.length haml_buffer.capture_position = position value = block.call(*args) captured = haml_buffer.buffer.slice!(position..-1) if captured == '' and value != haml_buffer.buffer captured = (value.is_a?(String) ? value : nil) end return nil if captured.nil? return (haml_buffer.options[:ugly] ? captured : prettify(captured)) end ensure haml_buffer.capture_position = nil end
Escapes HTML entities in `text`, but without escaping an ampersand that is already part of an escaped entity.
@param text [String] The string to sanitize @return [String] The sanitized string
# File lib/haml/helpers.rb, line 558 def escape_once(text) text = text.to_s text.gsub(HTML_ESCAPE_ONCE_REGEX, HTML_ESCAPE) end
Uses {#preserve} to convert any newlines inside whitespace-sensitive tags into the HTML entities for endlines.
@param tags [Array<String>] Tags that should have newlines escaped
@overload #find_and_preserve(input, tags = haml_buffer.options)
Escapes newlines within a string. @param input [String] The string within which to escape newlines
@overload #find_and_preserve(tags = haml_buffer.options)
Escapes newlines within a block of Haml code. @yield The block within which to escape newlines
# File lib/haml/helpers.rb, line 107 def find_and_preserve(input = nil, tags = haml_buffer.options[:preserve], &block) return find_and_preserve(capture_haml(&block), input || tags) if block re = /<(#{tags.map(&Regexp.method(:escape)).join('|')})([^>]*)>(.*?)(<\/\1>)/im input.to_s.gsub(re) do |s| s =~ re # Can't rely on $1, etc. existing since Rails' SafeBuffer#gsub is incompatible "<#{$1}#{$2}>#{preserve($3)}</#{$1}>" end end
Outputs text directly to the Haml buffer, with the proper indentation.
@param text [#to_s] The text to output
# File lib/haml/helpers.rb, line 387 def haml_concat(text = "") unless haml_buffer.options[:ugly] || haml_indent == 0 haml_buffer.buffer << haml_indent << text.to_s.gsub("\n", "\n" + haml_indent) << "\n" else haml_buffer.buffer << text.to_s << "\n" end ErrorReturn.new("haml_concat") end
@return [String] The indentation string for the current line
# File lib/haml/helpers.rb, line 398 def haml_indent ' ' * haml_buffer.tabulation end
Creates an HTML tag with the given name and optionally text and attributes. Can take a block that will run between the opening and closing tags. If the block is a Haml block or outputs text using {#haml_concat}, the text will be properly indented.
`name` can be a string using the standard Haml class/id shorthand (e.g. “span#foo.bar”, “#foo”). Just like standard Haml tags, these class and id values will be merged with manually-specified attributes.
`flags` is a list of symbol flags like those that can be put at the end of a Haml tag (`:/`, `:<`, and `:>`). Currently, only `:/` and `:<` are supported.
`haml_tag` outputs directly to the buffer; its return value should not be used. If you need to get the results as a string, use {#capture_haml}.
For example,
haml_tag :table do haml_tag :tr do haml_tag 'td.cell' do haml_tag :strong, "strong!" haml_concat "data" end haml_tag :td do haml_concat "more_data" end end end
outputs
<table> <tr> <td class='cell'> <strong> strong! </strong> data </td> <td> more_data </td> </tr> </table>
@param name [#to_s] The name of the tag
@overload #haml_tag(name, *rest, attributes = {})
@yield The block of Haml code within the tag
@overload #haml_tag(name, text, *flags, attributes = {})
@param text [#to_s] The text within the tag @param flags [Array<Symbol>] Haml end-of-tag flags
# File lib/haml/helpers.rb, line 459 def haml_tag(name, *rest, &block) ret = ErrorReturn.new("haml_tag") text = rest.shift.to_s unless [Symbol, Hash, NilClass].any? {|t| rest.first.is_a? t} flags = [] flags << rest.shift while rest.first.is_a? Symbol attrs = (rest.shift || {}) attrs.keys.each {|key| attrs[key.to_s] = attrs.delete(key)} unless attrs.empty? name, attrs = merge_name_and_attributes(name.to_s, attrs) attributes = Haml::Compiler.build_attributes(haml_buffer.html?, haml_buffer.options[:attr_wrapper], haml_buffer.options[:escape_attrs], haml_buffer.options[:hyphenate_data_attrs], attrs) if text.nil? && block.nil? && (haml_buffer.options[:autoclose].include?(name) || flags.include?(:/)) haml_concat "<#{name}#{attributes} />" return ret end if flags.include?(:/) raise Error.new(Error.message(:self_closing_content)) if text raise Error.new(Error.message(:illegal_nesting_self_closing)) if block end tag = "<#{name}#{attributes}>" if block.nil? text = text.to_s if text.include?("\n") haml_concat tag tab_up haml_concat text tab_down haml_concat "</#{name}>" else tag << text << "</#{name}>" haml_concat tag end return ret end if text raise Error.new(Error.message(:illegal_nesting_line, name)) end if flags.include?(:<) tag << capture_haml(&block).strip << "</#{name}>" haml_concat tag return ret end haml_concat tag tab_up block.call tab_down haml_concat "</#{name}>" ret end
Returns a hash containing default assignments for the `xmlns`, `lang`, and `xml:lang` attributes of the `html` HTML element. For example,
%html{html_attrs}
becomes
<html xmlns='http://www.w3.org/1999/xhtml' xml:lang='en-US' lang='en-US'>
@param lang [String] The value of `xml:lang` and `lang` @return [{#to_s => String}] The attribute hash
# File lib/haml/helpers.rb, line 221 def html_attrs(lang = 'en-US') {:xmlns => "http://www.w3.org/1999/xhtml", 'xml:lang' => lang, :lang => lang} end
Returns a copy of `text` with ampersands, angle brackets and quotes escaped into HTML entities.
Note that if ActionView is loaded and XSS protection is enabled (as is the default for Rails 3.0+, and optional for version 2.3.5+), this won't escape text declared as “safe”.
@param text [String] The string to sanitize @return [String] The sanitized string
# File lib/haml/helpers.rb, line 537 def html_escape(text) text = text.to_s text.gsub(HTML_ESCAPE_REGEX, HTML_ESCAPE) end
Note: this does *not* need to be called when using Haml helpers normally in Rails.
Initializes the current object as though it were in the same context as a normal ActionView instance using Haml. This is useful if you want to use the helpers in a context other than the normal setup with ActionView. For example:
context = Object.new class << context include Haml::Helpers end context.init_haml_helpers context.haml_tag :p, "Stuff"
# File lib/haml/helpers.rb, line 72 def init_haml_helpers @haml_buffer = Haml::Buffer.new(haml_buffer, Options.new.for_buffer) nil end
Returns whether or not the current template is a Haml template.
This function, unlike other {Haml::Helpers} functions, also works in other `ActionView` templates, where it will always return false.
@return [Boolean] Whether or not the current template is a Haml template
# File lib/haml/helpers.rb, line 576 def is_haml? !@haml_buffer.nil? && @haml_buffer.active? end
Takes an `Enumerable` object and a block and iterates over the enum, yielding each element to a Haml block and putting the result into `<li>` elements. This creates a list of the results of the block. For example:
= list_of([['hello'], ['yall']]) do |i| = i[0]
Produces:
<li>hello</li> <li>yall</li>
And:
= list_of({:title => 'All the stuff', :description => 'A book about all the stuff.'}) do |key, val| %3= key.humanize %= val
Produces:
<li> <h3>Title</h3> <p>All the stuff</p> </li> <li> <h3>Description</h3> <p>A book about all the stuff.</p> </li>
While:
= list_of(["Home", "About", "Contact", "FAQ"], {class: "nav", role: "nav"}) do |item| %{ href="#" }= item
Produces:
<li class='nav' role='nav'> <a href='#'>Home</a> </li> <li class='nav' role='nav'> <a href='#'>About</a> </li> <li class='nav' role='nav'> <a href='#'>Contact</a> </li> <li class='nav' role='nav'> <a href='#'>FAQ</a> </li> `[[class", "nav"], [role", "nav"]]` could have been used instead of `{class: "nav", role: "nav"}` (or any enumerable collection where each pair of items responds to #to_s)
@param enum [Enumerable] The list of objects to iterate over @param [Enumerable<#to_s,#to_s>] opts Each key/value pair will become an attribute pair for each list item element. @yield [item] A block which contains Haml code that goes within list items @yieldparam item An element of `enum`
# File lib/haml/helpers.rb, line 192 def list_of(enum, opts={}, &block) opts_attributes = opts.empty? ? "" : " ".<<(opts.map{|k,v| "#{k}='#{v}'" }.join(" ")) to_return = enum.collect do |i| result = capture_haml(i, &block) if result.count("\n") > 1 result = result.gsub("\n", "\n ") result = "\n #{result.strip}\n" else result = result.strip end %Q<li#{opts_attributes}>#{result}</li>! end to_return.join("\n") end
Runs a block of code in a non-Haml context (i.e. {#is_haml?} will return false).
This is mainly useful for rendering sub-templates such as partials in a non-Haml language, particularly where helpers may behave differently when run from Haml.
Note that this is automatically applied to Rails partials.
@yield A block which won't register as Haml
# File lib/haml/helpers.rb, line 86 def non_haml was_active = @haml_buffer.active? @haml_buffer.active = false yield ensure @haml_buffer.active = was_active end
Prepends a string to the beginning of a Haml block, with no whitespace between. For example:
= precede '*' do %span.small Not really
Produces:
*<span class='small'>Not really</span>
@param str [String] The string to add before the Haml @yield A block of Haml to prepend to
# File lib/haml/helpers.rb, line 325 def precede(str, &block) "#{str}#{capture_haml(&block).chomp}\n" end
Takes any string, finds all the newlines, and converts them to HTML entities so they'll render correctly in whitespace-sensitive tags without screwing up the indentation.
@overload perserve(input)
Escapes newlines within a string. @param input [String] The string within which to escape all newlines
@overload perserve
Escapes newlines within a block of Haml code. @yield The block within which to escape newlines
# File lib/haml/helpers.rb, line 128 def preserve(input = nil, &block) return preserve(capture_haml(&block)) if block input.to_s.chomp("\n").gsub(/\n/, '
').gsub(/\r/, '') end
Appends a string to the end of a Haml block, with no whitespace between. For example:
click = succeed '.' do %{:href=>"thing"} here
Produces:
click <a href='thing'>here</a>.
@param str [String] The string to add after the Haml @yield A block of Haml to append to
# File lib/haml/helpers.rb, line 344 def succeed(str, &block) "#{capture_haml(&block).chomp}#{str}\n" end
Surrounds a block of Haml code with strings, with no whitespace in between. For example:
= surround '(', ')' do %{:href => "food"} chicken
Produces:
(<a href='food'>chicken</a>)
and
= surround '*' do %strong angry
Produces:
*<strong>angry</strong>*
@param front [String] The string to add before the Haml @param back [String] The string to add after the Haml @yield A block of Haml to surround
# File lib/haml/helpers.rb, line 306 def surround(front, back = front, &block) output = capture_haml(&block) "#{front}#{output.chomp}#{back}\n" end
Decrements the number of tabs the buffer automatically adds to the lines of the template.
@param i [Fixnum] The number of tabs by which to decrease the indentation @see tab_up
# File lib/haml/helpers.rb, line 252 def tab_down(i = 1) haml_buffer.tabulation -= i end
Increments the number of tabs the buffer automatically adds to the lines of the template. For example:
%h1 foo - tab_up %p bar - tab_down %strong baz
Produces:
<h1>foo</h1> <p>bar</p> <strong>baz</strong>
@param i [Fixnum] The number of tabs by which to increase the indentation @see tab_down
# File lib/haml/helpers.rb, line 243 def tab_up(i = 1) haml_buffer.tabulation += i end
Sets the number of tabs the buffer automatically adds to the lines of the template, but only for the duration of the block. For example:
%h1 foo - with_tabs(2) do %p bar %strong baz
Produces:
<h1>foo</h1> <p>bar</p> <strong>baz</strong>
@param i [Fixnum] The number of tabs to use @yield A block in which the indentation will be `i` spaces
# File lib/haml/helpers.rb, line 275 def with_tabs(i) old_tabs = haml_buffer.tabulation haml_buffer.tabulation = i yield ensure haml_buffer.tabulation = old_tabs end
Private Instance Methods
Gives a proc the same local `_hamlout` and `_erbout` variables that the current template has.
@param proc [#call] The proc to bind @return [Proc] A new proc with the new variables bound
# File lib/haml/helpers.rb, line 627 def haml_bind_proc(&proc) _hamlout = haml_buffer #double assignment is to avoid warnings _erbout = _erbout = _hamlout.buffer proc { |*args| proc.call(*args) } end
The current {Haml::Buffer} object.
@return [Haml::Buffer]
# File lib/haml/helpers.rb, line 618 def haml_buffer @haml_buffer if defined? @haml_buffer end
Parses the tag name used for {#haml_tag} and merges it with the Ruby attributes hash.
# File lib/haml/helpers.rb, line 592 def merge_name_and_attributes(name, attributes_hash = {}) # skip merging if no ids or classes found in name return name, attributes_hash unless name =~ /^(.+?)?([\.#].*)$/ return $1 || "div", Buffer.merge_attrs( Haml::Parser.parse_class_and_id($2), attributes_hash) end
# File lib/haml/helpers.rb, line 634 def prettify(text) text = text.split(/^/) text.delete('') min_tabs = nil text.each do |line| tabs = line.index(/[^ ]/) || line.length min_tabs ||= tabs min_tabs = min_tabs > tabs ? tabs : min_tabs end text.map do |line| line.slice(min_tabs, line.length) end.join end
Runs a block of code with the given buffer as the currently active buffer.
@param buffer [Haml::Buffer] The Haml buffer to use temporarily @yield A block in which the given buffer should be used
# File lib/haml/helpers.rb, line 604 def with_haml_buffer(buffer) @haml_buffer, old_buffer = buffer, @haml_buffer old_buffer.active, old_was_active = false, old_buffer.active? if old_buffer @haml_buffer.active, was_active = true, @haml_buffer.active? yield ensure @haml_buffer.active = was_active old_buffer.active = old_was_active if old_buffer @haml_buffer = old_buffer end