Module: Haml::Util

Extended by:
Util
Included in:
Buffer, Util, Version, Sass::Engine, Sass::Plugin, Sass::Script::Color
Defined in:
lib/haml/util.rb

Overview

A module containing various useful functions.

Defined Under Namespace

Classes: StaticConditionalContext

Constant Summary collapse

RUBY_VERSION =

An array of ints representing the Ruby version number.

::RUBY_VERSION.split(".").map {|s| s.to_i}
@@silence_warnings = 
false

Instance Method Summary collapse

Instance Method Details

#ap_geq_3? ⇒ Boolean

Returns whether this environment is using ActionPack version 3.0.0 or greater.

Returns:

  • (Boolean) 


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# File 'lib/haml/util.rb', line 219

def ap_geq_3?
  # The ActionPack module is always loaded automatically in Rails >= 3
  return false unless defined?(ActionPack) && defined?(ActionPack::VERSION)

  version =
    if defined?(ActionPack::VERSION::MAJOR)
      ActionPack::VERSION::MAJOR
    else
      # Rails 1.2
      ActionPack::VERSION::Major
    end

  # 3.0.0.beta1 acts more like ActionPack 2
  # for purposes of this method
  # (checking whether block helpers require = or -).
  # This extra check can be removed when beta2 is out.
  version >= 3 &&
    !(defined?(ActionPack::VERSION::TINY) &&
      ActionPack::VERSION::TINY == "0.beta")
end

#assert_html_safe!(text)

Assert that a given object (usually a String) is HTML safe according to Rails' XSS handling, if it's loaded.

Parameters:

Raises:



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# File 'lib/haml/util.rb', line 280

def assert_html_safe!(text)
  return unless rails_xss_safe? && text && !text.to_s.html_safe?
  raise Haml::Error.new("Expected #{text.inspect} to be HTML-safe.")
end

#av_template_class(name)

Returns an ActionView::Template* class. In pre-3.0 versions of Rails, most of these classes were of the form ActionView::TemplateFoo, while afterwards they were of the form ActionView;:Template::Foo.

Parameters:

  • name (#to_s) —

    The name of the class to get. For example, :Error will return ActionView::TemplateError or ActionView::Template::Error.



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# File 'lib/haml/util.rb', line 248

def av_template_class(name)
  return ActionView.const_get("Template#{name}") if ActionView.const_defined?("Template#{name}")
  return ActionView::Template.const_get(name.to_s)
end

#caller_info(entry = ) ⇒ [String, Fixnum, (String, nil)]

Returns information about the caller of the previous method.

Parameters:

  • entry (String) (defaults to: ) —

    An entry in the #caller list, or a similarly formatted string

Returns:

  • ([String, Fixnum, (String, nil)]) —

    An array containing the filename, line, and method name of the caller. The method name may be nil



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# File 'lib/haml/util.rb', line 155

def caller_info(entry = caller[1])
  info = entry.scan(/^(.*?):(-?.*?)(?::.*`(.+)')?$/).first
  info[1] = info[1].to_i
  info
end

#check_encoding(str) {|msg| ... } ⇒ String

Checks that the encoding of a string is valid in Ruby 1.9 and cleans up potential encoding gotchas like the UTF-8 BOM. If it's not, yields an error string describing the invalid character and the line on which it occurrs.

Parameters:

  • str (String) —

    The string of which to check the encoding

Yields:

  • (msg) —

    A block in which an encoding error can be raised. Only yields if there is an encoding error

Yield Parameters:

  • msg (String) —

    The error message to be raised

Returns:

  • (String) —

    str, potentially with encoding gotchas like BOMs removed



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# File 'lib/haml/util.rb', line 309

def check_encoding(str)
  if ruby1_8?
    return str.gsub(/\A\xEF\xBB\xBF/, '') # Get rid of the UTF-8 BOM
  elsif str.valid_encoding?
    # Get rid of the Unicode BOM if possible
    if str.encoding.name =~ /^UTF-(8|16|32)(BE|LE)?$/
      return str.gsub(Regexp.new("\\A\uFEFF".encode(str.encoding.name)), '')
    else
      return str
    end
  end

  encoding = str.encoding
  newlines = Regexp.new("\r\n|\r|\n".encode(encoding).force_encoding("binary"))
  str.force_encoding("binary").split(newlines).each_with_index do |line, i|
    begin
      line.encode(encoding)
    rescue Encoding::UndefinedConversionError => e
      yield <<MSG.rstrip, i + 1
Invalid #{encoding.name} character #{e.error_char.dump}
MSG
    end
  end
  return str
end

#def_static_method(klass, name, args, *vars, erb)

This is used for methods in Buffer that need to be very fast, and take a lot of boolean parameters that are known at compile-time. Instead of passing the parameters in normally, a separate method is defined for every possible combination of those parameters; these are then called using #static_method_name.

To define a static method, an ERB template for the method is provided. All conditionals based on the static parameters are done as embedded Ruby within this template. For example:

def_static_method(Foo, :my_static_method, [:foo, :bar], :baz, :bang, <<RUBY)
  <% if baz && bang %>
    return foo + bar
  <% elsif baz || bang %>
    return foo - bar
  <% else %>
    return 17
  <% end %>
RUBY

#static_method_name can be used to call static methods.

Parameters:

  • klass (Module) —

    The class on which to define the static method

  • name (#to_s) —

    The (base) name of the static method

  • args (Array<Symbol>) —

    The names of the arguments to the defined methods (not to the ERB template)

  • vars (Array<Symbol>) —

    The names of the static boolean variables to be made available to the ERB template

  • erb (String) —

    The template for the method code



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# File 'lib/haml/util.rb', line 438

def def_static_method(klass, name, args, *vars)
  erb = vars.pop
  info = caller_info
  powerset(vars).each do |set|
    context = StaticConditionalContext.new(set).instance_eval {binding}
    klass.class_eval(<<METHOD, info[0], info[1])
def #{static_method_name(name, *vars.map {|v| set.include?(v)})}(#{args.join(', ')})
  #{ERB.new(erb).result(context)}
end
METHOD
  end
end

#enum_cons(enum, n) ⇒ Enumerator

A version of Enumerable#enum_cons that works in Ruby 1.8 and 1.9.

Parameters:

  • enum (Enumerable) —

    The enumerable to get the enumerator for

  • n (Fixnum) —

    The size of each cons

Returns:

  • (Enumerator) —

    The consed enumerator



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# File 'lib/haml/util.rb', line 366

def enum_cons(enum, n)
  ruby1_8? ? enum.enum_cons(n) : enum.each_cons(n)
end

#enum_slice(enum, n) ⇒ Enumerator

A version of Enumerable#enum_slice that works in Ruby 1.8 and 1.9.

Parameters:

  • enum (Enumerable) —

    The enumerable to get the enumerator for

  • n (Fixnum) —

    The size of each slice

Returns:

  • (Enumerator) —

    The consed enumerator



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# File 'lib/haml/util.rb', line 375

def enum_slice(enum, n)
  ruby1_8? ? enum.enum_slice(n) : enum.each_slice(n)
end

#enum_with_index(enum) ⇒ Enumerator

A version of Enumerable#enum_with_index that works in Ruby 1.8 and 1.9.

Parameters:

  • enum (Enumerable) —

    The enumerable to get the enumerator for

Returns:

  • (Enumerator) —

    The with-index enumerator



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# File 'lib/haml/util.rb', line 357

def enum_with_index(enum)
  ruby1_8? ? enum.enum_with_index : enum.each_with_index
end

#haml_warn(msg)

The same as Kernel#warn, but is silenced by #silence_haml_warnings.

Parameters:

  • msg (String) 


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# File 'lib/haml/util.rb', line 186

def haml_warn(msg)
  return if @@silence_warnings
  warn(msg)
end

#has?(attr, klass, method) ⇒ Boolean

Checks to see if a class has a given method. For example:

Haml::Util.has?(:public_instance_method, String, :gsub) #=> true

Method collections like Class#instance_methods return strings in Ruby 1.8 and symbols in Ruby 1.9 and on, so this handles checking for them in a compatible way.

Parameters:

  • attr (#to_s) —

    The (singular) name of the method-collection method (e.g. :instance_methods, :private_methods)

  • klass (Module) —

    The class to check the methods of which to check

  • method (String, Symbol) —

    The name of the method do check for

Returns:

  • (Boolean) —

    Whether or not the given collection has the given method



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# File 'lib/haml/util.rb', line 349

def has?(attr, klass, method)
  klass.send("#{attr}s").include?(ruby1_8? ? method.to_s : method.to_sym)
end

#html_safe(text) ⇒ String?

Returns the given text, marked as being HTML-safe. With older versions of the Rails XSS-safety mechanism, this destructively modifies the HTML-safety of text.

Parameters:

  • text (String, nil)

Returns:

  • (String, nil) —

    text, marked as HTML-safe



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# File 'lib/haml/util.rb', line 270

def html_safe(text)
  return unless text
  return text.html_safe if defined?(ActiveSupport::SafeBuffer)
  text.html_safe!
end

#map_hash(hash) {|key, value| ... } ⇒ Hash

Maps the key-value pairs of a hash according to a block. For example:

map_hash({:foo => "bar", :baz => "bang"}) {|k, v| [k.to_s, v.to_sym]}
  #=> {"foo" => :bar, "baz" => :bang}

Parameters:

  • hash (Hash) —

    The hash to map

Yields:

  • (key, value) —

    A block in which the key-value pairs are transformed

Yield Parameters:

  • The (key) —

    hash key

  • The (value) —

    hash value

Yield Returns:

  • ((Object, Object)) —

    The new value for the [key, value] pair

Returns:

  • (Hash) —

    The mapped hash

See Also:



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# File 'lib/haml/util.rb', line 83

def map_hash(hash, &block)
  to_hash(hash.map(&block))
end

#map_keys(hash) {|key| ... } ⇒ Hash

Maps the keys in a hash according to a block. For example:

map_keys({:foo => "bar", :baz => "bang"}) {|k| k.to_s}
  #=> {"foo" => "bar", "baz" => "bang"}

Parameters:

  • hash (Hash) —

    The hash to map

Yields:

  • (key) —

    A block in which the keys are transformed

Yield Parameters:

  • key (Object) —

    The key that should be mapped

Yield Returns:

  • (Object) —

    The new value for the key

Returns:

  • (Hash) —

    The mapped hash

See Also:



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# File 'lib/haml/util.rb', line 48

def map_keys(hash)
  to_hash(hash.map {|k, v| [yield(k), v]})
end

#map_vals(hash) {|value| ... } ⇒ Hash

Maps the values in a hash according to a block. For example:

map_values({:foo => "bar", :baz => "bang"}) {|v| v.to_sym}
  #=> {:foo => :bar, :baz => :bang}

Parameters:

  • hash (Hash) —

    The hash to map

Yields:

  • (value) —

    A block in which the values are transformed

Yield Parameters:

  • value (Object) —

    The value that should be mapped

Yield Returns:

  • (Object) —

    The new value for the value

Returns:

  • (Hash) —

    The mapped hash

See Also:



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# File 'lib/haml/util.rb', line 65

def map_vals(hash)
  to_hash(hash.map {|k, v| [k, yield(v)]})
end

#merge_adjacent_strings(enum) ⇒ Array

Concatenates all strings that are adjacent in an array, while leaving other elements as they are. For example:

merge_adjacent_strings([1, "foo", "bar", 2, "baz"])
  #=> [1, "foobar", 2, "baz"]

Parameters:

  • enum (Enumerable)

Returns:

  • (Array) —

    The enumerable with strings merged



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# File 'lib/haml/util.rb', line 127

def merge_adjacent_strings(enum)
  e = enum.inject([]) do |a, e|
    if e.is_a?(String) && a.last.is_a?(String)
      a.last << e
    else
      a << e
    end
    a
  end
end

#ord(c) ⇒ Fixnum

Returns the ASCII code of the given character.

Parameters:

  • c (String) —

    All characters but the first are ignored.

Returns:

  • (Fixnum) —

    The ASCII code of c.



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# File 'lib/haml/util.rb', line 383

def ord(c)
  ruby1_8? ? c[0] : c.ord
end

#powerset(arr) ⇒ Set<Set>

Computes the powerset of the given array. This is the set of all subsets of the array. For example:

powerset([1, 2, 3]) #=>
  Set[Set[], Set[1], Set[2], Set[3], Set[1, 2], Set[2, 3], Set[1, 3], Set[1, 2, 3]]

Parameters:

  • arr (Enumerable)

Returns:

  • (Set<Set>) —

    The subsets of arr



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# File 'lib/haml/util.rb', line 96

def powerset(arr)
  arr.inject([Set.new].to_set) do |powerset, el|
    new_powerset = Set.new
    powerset.each do |subset|
      new_powerset << subset
      new_powerset << subset + [el]
    end
    new_powerset
  end
end

#rails_env ⇒ String?

Returns the environment of the Rails application, if this is running in a Rails context. Returns nil if no such environment is defined.

Returns:

  • (String, nil) 


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# File 'lib/haml/util.rb', line 209

def rails_env
  return Rails.env.to_s if defined?(Rails.root)
  return RAILS_ENV.to_s if defined?(RAILS_ENV)
  return nil
end

#rails_root ⇒ String?

Returns the root of the Rails application, if this is running in a Rails context. Returns nil if no such root is defined.

Returns:

  • (String, nil) 


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# File 'lib/haml/util.rb', line 198

def rails_root
  return Rails.root.to_s if defined?(Rails.root)
  return RAILS_ROOT.to_s if defined?(RAILS_ROOT)
  return nil
end

#rails_safe_buffer_class 



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# File 'lib/haml/util.rb', line 285

def rails_safe_buffer_class
  return ActionView::SafeBuffer if defined?(ActionView::SafeBuffer)
  ActiveSupport::SafeBuffer
end

#rails_xss_safe? ⇒ Boolean

Whether or not ActionView's XSS protection is available and enabled, as is the default for Rails 3.0+, and optional for version 2.3.5+. Overridden in haml/template.rb if this is the case.

Returns:

  • (Boolean) 


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# File 'lib/haml/util.rb', line 260

def rails_xss_safe?
  false
end

#restrict(value, range) ⇒ Numeric

Restricts a number to falling within a given range. Returns the number if it falls within the range, or the closest value in the range if it doesn't.

Parameters:

  • value (Numeric)
  • range (Range<Numeric>)

Returns:

  • (Numeric) 


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# File 'lib/haml/util.rb', line 114

def restrict(value, range)
  [[value, range.first].max, range.last].min
end

#ruby1_8? ⇒ Boolean

Whether or not this is running under Ruby 1.8 or lower.

Returns:

  • (Boolean) 


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# File 'lib/haml/util.rb', line 295

def ruby1_8?
  Haml::Util::RUBY_VERSION[0] == 1 && Haml::Util::RUBY_VERSION[1] < 9
end

#scope(file) ⇒ String

Returns the path of a file relative to the Haml root directory.

Parameters:

  • file (String) —

    The filename relative to the Haml root

Returns:

  • (String) —

    The filename relative to the the working directory



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# File 'lib/haml/util.rb', line 19

def scope(file)
  File.join(Haml::ROOT_DIR, file)
end

#silence_haml_warnings { ... }

Silences all Haml warnings within a block.

Yields:

  • A block in which no Haml warnings will be printed



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# File 'lib/haml/util.rb', line 175

def silence_haml_warnings
  old_silence_warnings = @@silence_warnings
  @@silence_warnings = true
  yield
ensure
  @@silence_warnings = old_silence_warnings
end

#silence_warnings { ... }

Silence all output to STDERR within a block.

Yields:

  • A block in which no output will be printed to STDERR



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# File 'lib/haml/util.rb', line 164

def silence_warnings
  the_real_stderr, $stderr = $stderr, StringIO.new
  yield
ensure
  $stderr = the_real_stderr
end

#static_method_name(name, *vars) ⇒ String

Computes the name for a method defined via #def_static_method.

Parameters:

  • name (String) —

    The base name of the static method

  • vars (Array<Boolean>) —

    The static variable assignment

Returns:

  • (String) —

    The real name of the static method



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# File 'lib/haml/util.rb', line 456

def static_method_name(name, *vars)
  "#{name}_#{vars.map {|v| !!v}.join('_')}"
end

#strip_string_array(arr) ⇒ Array

Destructively strips whitespace from the beginning and end of the first and last elements, respectively, in the array (if those elements are strings).

Parameters:

  • arr (Array)

Returns:

  • (Array) —

    arr



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# File 'lib/haml/util.rb', line 144

def strip_string_array(arr)
  arr.first.lstrip! if arr.first.is_a?(String)
  arr.last.rstrip! if arr.last.is_a?(String)
  arr
end

#to_hash(arr) ⇒ Hash

Converts an array of [key, value] pairs to a hash. For example:

to_hash([[:foo, "bar"], [:baz, "bang"]])
  #=> {:foo => "bar", :baz => "bang"}

Parameters:

Returns:

  • (Hash) —

    A hash



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# File 'lib/haml/util.rb', line 31

def to_hash(arr)
  arr.compact.inject({}) {|h, (k, v)| h[k] = v; h}
end