class Haml::Buffer

This class is used only internally. It holds the buffer of HTML that is eventually output as the resulting document. It's called from within the precompiled code, and helps reduce the amount of processing done within `instance_eval`ed code.

Attributes

active[W]

@return [Boolean] @see active?

buffer[RW]

The string that holds the compiled HTML. This is aliased as `_erbout` for compatibility with ERB-specific code.

@return [String]

capture_position[RW]

nil if there's no capture_haml block running, and the position at which it's beginning the capture if there is one.

@return [Fixnum, nil]

options[RW]

The options hash passed in from {Haml::Engine}.

@return [{String => Object}] @see Haml::Options#for_buffer

upper[RW]

The {Buffer} for the enclosing Haml document. This is set for partials and similar sorts of nested templates. It's `nil` at the top level (see {#toplevel?}).

@return [Buffer]

Public Class Methods

merge_attrs(to, from) click to toggle source

Merges two attribute hashes. This is the same as `to.merge!(from)`, except that it merges id, class, and data attributes.

ids are concatenated with `“_”`, and classes are concatenated with `“ ”`. data hashes are simply merged.

Destructively modifies both `to` and `from`.

@param to [{String => String}] The attribute hash to merge into @param from [{String => to_s}] The attribute hash to merge from @return [{String => String}] `to`, after being merged

# File lib/haml/buffer.rb, line 233
def self.merge_attrs(to, from)
  from['id'] = Compiler.filter_and_join(from['id'], '_') if from['id']
  if to['id'] && from['id']
    to['id'] << '_' << from.delete('id').to_s
  elsif to['id'] || from['id']
    from['id'] ||= to['id']
  end

  from['class'] = Compiler.filter_and_join(from['class'], ' ') if from['class']
  if to['class'] && from['class']
    # Make sure we don't duplicate class names
    from['class'] = (from['class'].to_s.split(' ') | to['class'].split(' ')).sort.join(' ')
  elsif to['class'] || from['class']
    from['class'] ||= to['class']
  end

  from_data = from.delete('data') || {}
  to_data = to.delete('data') || {}

  # forces to_data & from_data into a hash
  from_data = { nil => from_data } unless from_data.is_a?(Hash)
  to_data = { nil => to_data } unless to_data.is_a?(Hash)

  merged_data = to_data.merge(from_data)

  to['data'] = merged_data unless merged_data.empty?
  to.merge!(from)
end
new(upper = nil, options = {}) click to toggle source

@param upper [Buffer] The parent buffer @param options [{Symbol => Object}] An options hash.

See {Haml::Engine#options\_for\_buffer}
# File lib/haml/buffer.rb, line 90
def initialize(upper = nil, options = {})
  @active     = true
  @upper      = upper
  @options    = options
  @buffer     = new_encoded_string
  @tabulation = 0

  # The number of tabs that Engine thinks we should have
  # @real_tabs + @tabulation is the number of tabs actually output
  @real_tabs = 0
end

Public Instance Methods

active?() click to toggle source

Whether or not this buffer is currently being used to render a Haml template. Returns `false` if a subtemplate is being rendered, even if it's a subtemplate of this buffer's template.

@return [Boolean]

# File lib/haml/buffer.rb, line 70
def active?
  @active
end
adjust_tabs(tab_change) click to toggle source

Modifies the indentation of the document.

@param tab_change [Fixnum] The number of tabs by which to increase

or decrease the document's indentation
# File lib/haml/buffer.rb, line 126
def adjust_tabs(tab_change)
  @real_tabs += tab_change
end
attributes(class_id, obj_ref, *attributes_hashes) click to toggle source
# File lib/haml/buffer.rb, line 199
def attributes(class_id, obj_ref, *attributes_hashes)
  attributes = class_id
  attributes_hashes.each do |old|
    self.class.merge_attrs(attributes, Hash[old.map {|k, v| [k.to_s, v]}])
  end
  self.class.merge_attrs(attributes, parse_object_ref(obj_ref)) if obj_ref
  Compiler.build_attributes(
    html?, @options[:attr_wrapper], @options[:escape_attrs], @options[:hyphenate_data_attrs], attributes)
end
html4?() click to toggle source

@return [Boolean] Whether or not the format is HTML4

# File lib/haml/buffer.rb, line 50
def html4?
  @options[:format] == :html4
end
html5?() click to toggle source

@return [Boolean] Whether or not the format is HTML5.

# File lib/haml/buffer.rb, line 55
def html5?
  @options[:format] == :html5
end
html?() click to toggle source

@return [Boolean] Whether or not the format is any flavor of HTML

# File lib/haml/buffer.rb, line 45
def html?
  html4? or html5?
end
push_text(text, tab_change, dont_tab_up) click to toggle source

Appends text to the buffer, properly tabulated. Also modifies the document's indentation.

@param text [String] The text to append @param tab_change [Fixnum] The number of tabs by which to increase

or decrease the document's indentation

@param dont_tab_up [Boolean] If true, don't indent the first line of `text`

# File lib/haml/buffer.rb, line 109
def push_text(text, tab_change, dont_tab_up)
  if @tabulation > 0
    # Have to push every line in by the extra user set tabulation.
    # Don't push lines with just whitespace, though,
    # because that screws up precompiled indentation.
    text.gsub!(/^(?!\s+$)/m, tabs)
    text.sub!(tabs, '') if dont_tab_up
  end

  @buffer << text
  @real_tabs += tab_change
end
rstrip!() click to toggle source

Remove the whitespace from the right side of the buffer string. Doesn't do anything if we're at the beginning of a capture_haml block.

# File lib/haml/buffer.rb, line 211
def rstrip!
  if capture_position.nil?
    buffer.rstrip!
    return
  end

  buffer << buffer.slice!(capture_position..-1).rstrip
end
tabulation() click to toggle source

@return [Fixnum] The current indentation level of the document

# File lib/haml/buffer.rb, line 75
def tabulation
  @real_tabs + @tabulation
end
tabulation=(val) click to toggle source

Sets the current tabulation of the document.

@param val [Fixnum] The new tabulation

# File lib/haml/buffer.rb, line 82
def tabulation=(val)
  val = val - @real_tabs
  @tabulation = val > -1 ? val : 0
end
toplevel?() click to toggle source

@return [Boolean] Whether or not this buffer is a top-level template,

as opposed to a nested partial
# File lib/haml/buffer.rb, line 61
def toplevel?
  upper.nil?
end
xhtml?() click to toggle source

@return [Boolean] Whether or not the format is XHTML

# File lib/haml/buffer.rb, line 40
def xhtml?
  not html?
end

Private Instance Methods

fix_textareas!(input) click to toggle source

Works like #{find_and_preserve}, but allows the first newline after a preserved opening tag to remain unencoded, and then outdents the content. This change was motivated primarily by the change in Rails 3.2.3 to emit a newline after textarea helpers.

@param input [String] The text to process @since Haml 4.0.1 @private

# File lib/haml/buffer.rb, line 272
def fix_textareas!(input)
  pattern = /([ ]*)<(textarea)([^>]*)>(\n|&#x000A;)(.*?)(<\/\2>)/im
  input.gsub!(pattern) do |s|
    match = pattern.match(s)
    content = match[5]
    if match[4] == '&#x000A;'
      content.sub!(/\A /, '&#x0020;')
    else
      content.sub!(/\A[ ]*/, '')
    end
    "#{match[1]}<#{match[2]}#{match[3]}>\n#{content}</#{match[2]}>"
  end
end
new_encoded_string() click to toggle source
# File lib/haml/buffer.rb, line 287
def new_encoded_string
  ""
end
parse_object_ref(ref) click to toggle source

Takes an array of objects and uses the class and id of the first one to create an attributes hash. The second object, if present, is used as a prefix, just like you can do with `dom_id()` and `dom_class()` in Rails

# File lib/haml/buffer.rb, line 307
def parse_object_ref(ref)
  prefix = ref[1]
  ref = ref[0]
  # Let's make sure the value isn't nil. If it is, return the default Hash.
  return {} if ref.nil?
  class_name =
    if ref.respond_to?(:haml_object_ref)
      ref.haml_object_ref
    else
      underscore(ref.class)
    end
  ref_id =
    if ref.respond_to?(:to_key)
      key = ref.to_key
      key.join('_') unless key.nil?
    else
      ref.id
    end
  id = "#{class_name}_#{ref_id || 'new'}"
  if prefix
    class_name = "#{ prefix }_#{ class_name}"
    id = "#{ prefix }_#{ id }"
  end

  {'id' => id, 'class' => class_name}
end
tabs(count = 0) click to toggle source

Gets `count` tabs. Mostly for internal use.

# File lib/haml/buffer.rb, line 298
def tabs(count = 0)
  tabs = [count + @tabulation, 0].max
  @@tab_cache[tabs] ||= '  ' * tabs
end
underscore(camel_cased_word) click to toggle source

Changes a word from camel case to underscores. Based on the method of the same name in Rails' Inflector, but copied here so it'll run properly without Rails.

# File lib/haml/buffer.rb, line 337
def underscore(camel_cased_word)
  camel_cased_word.to_s.gsub(/::/, '_').
    gsub(/([A-Z]+)([A-Z][a-z])/,'\1_\2').
    gsub(/([a-z\d])([A-Z])/,'\1_\2').
    tr("-", "_").
    downcase
end