Module | Haml::Helpers |
In: |
lib/haml/helpers.rb
lib/haml/helpers/action_view_extensions.rb |
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.
HTML_ESCAPE | = | { '&'=>'&', '<'=>'<', '>'=>'>', '"'=>'"', "'"=>''', } | Characters that need to be escaped to HTML entities from user input |
Returns whether or not ActionView is installed on the system.
# File lib/haml/helpers.rb, line 16 16: def self.action_view? 17: @@action_view_defined 18: end
Captures the result of the given 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| %p= a
the local variable foo would be assigned to "<p>13</p>\n".
# File lib/haml/helpers.rb, line 256 256: def capture_haml(*args, &block) 257: buffer = eval('_hamlout', block.binding) rescue haml_buffer 258: with_haml_buffer(buffer) do 259: position = haml_buffer.buffer.length 260: 261: block.call(*args) 262: 263: captured = haml_buffer.buffer.slice!(position..-1).split(/^/) 264: 265: min_tabs = nil 266: captured.each do |line| 267: tabs = line.index(/[^ ]/) || line.length 268: min_tabs ||= tabs 269: min_tabs = min_tabs > tabs ? tabs : min_tabs 270: end 271: 272: captured.map do |line| 273: line[min_tabs..-1] 274: end.join 275: end 276: end
Uses preserve to convert any newlines inside whitespace-sensitive tags into the HTML entities for endlines. @tags@ is an array of tags to preserve. It defaults to the value of the :preserve option.
# File lib/haml/helpers.rb, line 70 70: def find_and_preserve(input = '', tags = haml_buffer.options[:preserve], &block) 71: return find_and_preserve(capture_haml(&block)) if block 72: 73: input = input.to_s 74: input.gsub(/<(#{tags.map(&Regexp.method(:escape)).join('|')})([^>]*)>(.*?)(<\/\1>)/im) do 75: "<#{$1}#{$2}>#{preserve($3)}</#{$1}>" 76: end 77: end
Returns the string that should be used to indent the current line
# File lib/haml/helpers.rb, line 295 295: def haml_indent 296: ' ' * haml_buffer.tabulation 297: end
Creates an HTML tag with the given name and optionally text and attributes. Can take a block that will be executed between when the opening and closing tags are output. If the block is a Haml block or outputs text using haml_concat, the text will be properly indented.
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.
For example,
haml_tag :table do haml_tag :tr do haml_tag :td, {:class => '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>
# File lib/haml/helpers.rb, line 345 345: def haml_tag(name, *rest, &block) 346: name = name.to_s 347: text = rest.shift.to_s unless [Symbol, Hash, NilClass].any? {|t| rest.first.is_a? t} 348: flags = [] 349: flags << rest.shift while rest.first.is_a? Symbol 350: attributes = Haml::Precompiler.build_attributes(haml_buffer.html?, 351: haml_buffer.options[:attr_wrapper], 352: rest.shift || {}) 353: 354: if text.nil? && block.nil? && (haml_buffer.options[:autoclose].include?(name) || flags.include?(:/)) 355: haml_concat "<#{name}#{attributes} />" 356: return nil 357: end 358: 359: if flags.include?(:/) 360: raise Error.new("Self-closing tags can't have content.") if text 361: raise Error.new("Illegal nesting: nesting within a self-closing tag is illegal.") if block 362: end 363: 364: tag = "<#{name}#{attributes}>" 365: if block.nil? 366: tag << text.to_s << "</#{name}>" 367: haml_concat tag 368: return 369: end 370: 371: if text 372: raise Error.new("Illegal nesting: content can't be both given to haml_tag :#{name} and nested within it.") 373: end 374: 375: if flags.include?(:<) 376: tag << capture_haml(&block).strip << "</#{name}>" 377: haml_concat tag 378: return 379: end 380: 381: haml_concat tag 382: tab_up 383: block.call 384: tab_down 385: haml_concat "</#{name}>" 386: nil 387: end
Returns a hash containing default assignments for the xmlns and xml:lang attributes of the html HTML element. It also takes an optional argument for the value of xml:lang and lang, which defaults to ‘en-US’. For example,
%html{html_attrs}
becomes
<html xmlns='http://www.w3.org/1999/xhtml' xml:lang='en-US' lang='en-US'>
# File lib/haml/helpers.rb, line 154 154: def html_attrs(lang = 'en-US') 155: {:xmlns => "http://www.w3.org/1999/xhtml", 'xml:lang' => lang, :lang => lang} 156: 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 rendering 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 39 39: def init_haml_helpers 40: @haml_buffer = Haml::Buffer.new(@haml_buffer, Haml::Engine.new('').send(:options_for_buffer)) 41: nil 42: 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.
# File lib/haml/helpers.rb, line 409 409: def is_haml? 410: !@haml_buffer.nil? && @haml_buffer.active? 411: end
Takes an Enumerable object and a block and iterates over the object, 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| %h3= key.humanize %p= 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>
# File lib/haml/helpers.rb, line 126 126: def list_of(array, &block) # :yields: item 127: to_return = array.collect do |i| 128: result = capture_haml(i, &block) 129: 130: if result.count("\n") > 1 131: result.gsub!("\n", "\n ") 132: result = "\n #{result.strip}\n" 133: else 134: result.strip! 135: end 136: 137: "<li>#{result}</li>" 138: end 139: to_return.join("\n") 140: 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.
# File lib/haml/helpers.rb, line 54 54: def non_haml 55: was_active = @haml_buffer.active? 56: @haml_buffer.active = false 57: yield 58: ensure 59: @haml_buffer.active = was_active 60: end
Prepends the given character to the beginning of the Haml block, with no whitespace between. For example:
= precede '*' do %span.small Not really
Produces:
*<span class='small'>Not really</span>
# File lib/haml/helpers.rb, line 224 224: def precede(char, &block) 225: "#{char}#{capture_haml(&block).chomp}\n" 226: end
Takes any string, finds all the endlines and converts them to HTML entities for endlines so they‘ll render correctly in whitespace-sensitive tags without screwing up the indentation.
# File lib/haml/helpers.rb, line 86 86: def preserve(input = '', &block) 87: return preserve(capture_haml(&block)) if block 88: 89: input.chomp("\n").gsub(/\n/, '
').gsub(/\r/, '') 90: end
Appends the given character to the end of the Haml block, with no whitespace between. For example:
click = succeed '.' do %a{:href=>"thing"} here
Produces:
click <a href='thing'>here</a>.
# File lib/haml/helpers.rb, line 241 241: def succeed(char, &block) 242: "#{capture_haml(&block).chomp}#{char}\n" 243: end
Surrounds the given block of Haml code with the given characters, with no whitespace in between. For example:
= surround '(', ')' do %a{:href => "food"} chicken
Produces:
(<a href='food'>chicken</a>)
and
= surround '*' do %strong angry
Produces:
*<strong>angry</strong>*
# File lib/haml/helpers.rb, line 206 206: def surround(front, back = nil, &block) 207: back ||= front 208: output = capture_haml(&block) 209: 210: "#{front}#{output.chomp}#{back}\n" 211: 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>
# File lib/haml/helpers.rb, line 174 174: def tab_up(i = 1) 175: haml_buffer.tabulation += i 176: end