Module Haml::Util
In: lib/haml/util/subset_map.rb
lib/haml/util.rb

A module containing various useful functions.

Methods

Classes and Modules

Class Haml::Util::SubsetMap

Constants

RUBY_VERSION = ::RUBY_VERSION.split(".").map {|s| s.to_i}   An array of ints representing the Ruby version number. @api public
ENCODINGS_TO_CHECK = %w[UTF-8 UTF-16BE UTF-16LE UTF-32BE UTF-32LE]   We could automatically add in any non-ASCII-compatible encodings here, but there‘s not really a good way to do that without manually checking that each encoding encodes all ASCII characters properly, which takes long enough to affect the startup time of the CLI.
CHARSET_REGEXPS = Hash.new do |h, e| h[e] = begin # /\A(?:\uFEFF)?@charset "(.*?)"|\A(\uFEFF)/ Regexp.new(/\A(?:#{_enc("\uFEFF", e)})?#{ _enc('@charset "', e)}(.*?)#{_enc('"', e)}|\A(#{ _enc("\uFEFF", e)})/)

Public Instance methods

@private

[Source]

     # File lib/haml/util.rb, line 520
520:       def _enc(string, encoding)
521:         string.encode(encoding).force_encoding("BINARY")
522:       end

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

@return [Boolean]

[Source]

     # File lib/haml/util.rb, line 293
293:     def ap_geq_3?
294:       # The ActionPack module is always loaded automatically in Rails >= 3
295:       return false unless defined?(ActionPack) && defined?(ActionPack::VERSION)
296: 
297:       version =
298:         if defined?(ActionPack::VERSION::MAJOR)
299:           ActionPack::VERSION::MAJOR
300:         else
301:           # Rails 1.2
302:           ActionPack::VERSION::Major
303:         end
304: 
305:       version >= 3
306:     end

Returns whether this environment is using ActionPack version 3.0.0.beta.3 or greater.

@return [Boolean]

[Source]

     # File lib/haml/util.rb, line 312
312:     def ap_geq_3_beta_3?
313:       # The ActionPack module is always loaded automatically in Rails >= 3
314:       return false unless defined?(ActionPack) && defined?(ActionPack::VERSION)
315: 
316:       version =
317:         if defined?(ActionPack::VERSION::MAJOR)
318:           ActionPack::VERSION::MAJOR
319:         else
320:           # Rails 1.2
321:           ActionPack::VERSION::Major
322:         end
323:       version >= 3 &&
324:         ((defined?(ActionPack::VERSION::TINY) &&
325:           ActionPack::VERSION::TINY.is_a?(Fixnum) &&
326:           ActionPack::VERSION::TINY >= 1) ||
327:          (defined?(ActionPack::VERSION::BUILD) &&
328:           ActionPack::VERSION::BUILD =~ /beta(\d+)/ &&
329:           $1.to_i >= 3))
330:     end

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

@param text [Object]

[Source]

     # File lib/haml/util.rb, line 372
372:     def assert_html_safe!(text)
373:       return unless rails_xss_safe? && text && !text.to_s.html_safe?
374:       raise Haml::Error.new("Expected #{text.inspect} to be HTML-safe.")
375:     end

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`.

@param name [to_s] The name of the class to get.

  For example, `:Error` will return `ActionView::TemplateError`
  or `ActionView::Template::Error`.

[Source]

     # File lib/haml/util.rb, line 340
340:     def av_template_class(name)
341:       return ActionView.const_get("Template#{name}") if ActionView.const_defined?("Template#{name}")
342:       return ActionView::Template.const_get(name.to_s)
343:     end

Returns information about the caller of the previous method.

@param entry [String] An entry in the `caller` list, or a similarly formatted string @return [[String, Fixnum, (String, nil)]] An array containing the filename, line, and method name of the caller.

  The method name may be nil

[Source]

     # File lib/haml/util.rb, line 224
224:     def caller_info(entry = caller[1])
225:       info = entry.scan(/^(.*?):(-?.*?)(?::.*`(.+)')?$/).first
226:       info[1] = info[1].to_i
227:       # This is added by Rubinius to designate a block, but we don't care about it.
228:       info[2].sub!(/ \{\}\Z/, '') if info[2]
229:       info
230:     end

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.

@param str [String] The string of which to check the encoding @yield [msg] A block in which an encoding error can be raised.

  Only yields if there is an encoding error

@yieldparam msg [String] The error message to be raised @return [String] `str`, potentially with encoding gotchas like BOMs removed

[Source]

     # File lib/haml/util.rb, line 416
416:     def check_encoding(str)
417:       if ruby1_8?
418:         return str.gsub(/\A\xEF\xBB\xBF/, '') # Get rid of the UTF-8 BOM
419:       elsif str.valid_encoding?
420:         # Get rid of the Unicode BOM if possible
421:         if str.encoding.name =~ /^UTF-(8|16|32)(BE|LE)?$/
422:           return str.gsub(Regexp.new("\\A\uFEFF".encode(str.encoding.name)), '')
423:         else
424:           return str
425:         end
426:       end
427: 
428:       encoding = str.encoding
429:       newlines = Regexp.new("\r\n|\r|\n".encode(encoding).force_encoding("binary"))
430:       str.force_encoding("binary").split(newlines).each_with_index do |line, i|
431:         begin
432:           line.encode(encoding)
433:         rescue Encoding::UndefinedConversionError => e
434:           yield <<MSG.rstrip, i + 1
435: Invalid #{encoding.name} character #{e.error_char.dump}
436: MSG
437:         end
438:       end
439:       return str
440:     end

Like {\check_encoding}, but also checks for a Ruby-style `-# coding:` comment at the beginning of the template and uses that encoding if it exists.

The Sass encoding rules are simple. If a `-# coding:` comment exists, we assume that that‘s the original encoding of the document. Otherwise, we use whatever encoding Ruby has.

Haml uses the same rules for parsing coding comments as Ruby. This means that it can understand Emacs-style comments (e.g. `-*- encoding: "utf-8" -*-`), and also that it cannot understand non-ASCII-compatible encodings such as `UTF-16` and `UTF-32`.

@param str [String] The Haml template of which to check the encoding @yield [msg] A block in which an encoding error can be raised.

  Only yields if there is an encoding error

@yieldparam msg [String] The error message to be raised @return [String] The original string encoded properly @raise [ArgumentError] if the document declares an unknown encoding

[Source]

     # File lib/haml/util.rb, line 462
462:     def check_haml_encoding(str, &block)
463:       return check_encoding(str, &block) if ruby1_8?
464: 
465:       bom, encoding = parse_haml_magic_comment(str)
466:       if encoding; str.force_encoding(encoding)
467:       elsif bom; str.force_encoding("UTF-8")
468:       end
469: 
470:       return check_encoding(str, &block)
471:     end

Like {\check_encoding}, but also checks for a `@charset` declaration at the beginning of the file and uses that encoding if it exists.

The Sass encoding rules are simple. If a `@charset` declaration exists, we assume that that‘s the original encoding of the document. Otherwise, we use whatever encoding Ruby has. Then we convert that to UTF-8 to process internally. The UTF-8 end result is what‘s returned by this method.

@param str [String] The string of which to check the encoding @yield [msg] A block in which an encoding error can be raised.

  Only yields if there is an encoding error

@yieldparam msg [String] The error message to be raised @return [(String, Encoding)] The original string encoded as UTF-8,

  and the source encoding of the string (or `nil` under Ruby 1.8)

@raise [Encoding::UndefinedConversionError] if the source encoding

  cannot be converted to UTF-8

@raise [ArgumentError] if the document uses an unknown encoding with `@charset`

[Source]

     # File lib/haml/util.rb, line 492
492:     def check_sass_encoding(str, &block)
493:       return check_encoding(str, &block), nil if ruby1_8?
494:       # We allow any printable ASCII characters but double quotes in the charset decl
495:       bin = str.dup.force_encoding("BINARY")
496:       encoding = Haml::Util::ENCODINGS_TO_CHECK.find do |enc|
497:         bin =~ Haml::Util::CHARSET_REGEXPS[enc]
498:       end
499:       charset, bom = $1, $2
500:       if charset
501:         charset = charset.force_encoding(encoding).encode("UTF-8")
502:         if endianness = encoding[/[BL]E$/]
503:           begin
504:             Encoding.find(charset + endianness)
505:             charset << endianness
506:           rescue ArgumentError # Encoding charset + endianness doesn't exist
507:           end
508:         end
509:         str.force_encoding(charset)
510:       elsif bom
511:         str.force_encoding(encoding)
512:       end
513: 
514:       str = check_encoding(str, &block)
515:       return str.encode("UTF-8"), str.encoding
516:     end

The same as `Kernel#warn`, but is silenced by \{silence_haml_warnings}.

@param msg [String]

[Source]

     # File lib/haml/util.rb, line 257
257:     def haml_warn(msg)
258:       return if @@silence_warnings
259:       warn(msg)
260:     end

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`.

@param text [String, nil] @return [String, nil] `text`, marked as HTML-safe

[Source]

     # File lib/haml/util.rb, line 362
362:     def html_safe(text)
363:       return unless text
364:       return text.html_safe if defined?(ActiveSupport::SafeBuffer)
365:       text.html_safe!
366:     end

Intersperses a value in an enumerable, as would be done with `Array#join` but without concatenating the array together afterwards.

@param enum [Enumerable] @param val @return [Array]

[Source]

     # File lib/haml/util.rb, line 151
151:     def intersperse(enum, val)
152:       enum.inject([]) {|a, e| a << e << val}[0...-1]
153:     end

Computes a single longest common subsequence for `x` and `y`. If there are more than one longest common subsequences, the one returned is that which starts first in `x`.

@param x [Array] @param y [Array] @yield [a, b] An optional block to use in place of a check for equality

  between elements of `x` and `y`.

@yieldreturn [Object, nil] If the two values register as equal,

  this will return the value to use in the LCS array.

@return [Array] The LCS

[Source]

     # File lib/haml/util.rb, line 212
212:     def lcs(x, y, &block)
213:       x = [nil, *x]
214:       y = [nil, *y]
215:       block ||= proc {|a, b| a == b && a}
216:       lcs_backtrace(lcs_table(x, y, &block), x, y, x.size-1, y.size-1, &block)
217:     end

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}

@param hash [Hash] The hash to map @yield [key, value] A block in which the key-value pairs are transformed @yieldparam [key] The hash key @yieldparam [value] The hash value @yieldreturn [(Object, Object)] The new value for the `[key, value]` pair @return [Hash] The mapped hash @see map_keys @see map_vals

[Source]

    # File lib/haml/util.rb, line 86
86:     def map_hash(hash, &block)
87:       to_hash(hash.map(&block))
88:     end

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"}

@param hash [Hash] The hash to map @yield [key] A block in which the keys are transformed @yieldparam key [Object] The key that should be mapped @yieldreturn [Object] The new value for the key @return [Hash] The mapped hash @see map_vals @see map_hash

[Source]

    # File lib/haml/util.rb, line 51
51:     def map_keys(hash)
52:       to_hash(hash.map {|k, v| [yield(k), v]})
53:     end

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}

@param hash [Hash] The hash to map @yield [value] A block in which the values are transformed @yieldparam value [Object] The value that should be mapped @yieldreturn [Object] The new value for the value @return [Hash] The mapped hash @see map_keys @see map_hash

[Source]

    # File lib/haml/util.rb, line 68
68:     def map_vals(hash)
69:       to_hash(hash.map {|k, v| [k, yield(v)]})
70:     end

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"]

@param enum [Enumerable] @return [Array] The enumerable with strings merged

[Source]

     # File lib/haml/util.rb, line 130
130:     def merge_adjacent_strings(enum)
131:       enum.inject([]) do |a, e|
132:         if e.is_a?(String)
133:           if a.last.is_a?(String)
134:             a.last << e
135:           else
136:             a << e.dup
137:           end
138:         else
139:           a << e
140:         end
141:         a
142:       end
143:     end

Return an array of all possible paths through the given arrays.

@param arrs [Array<Array>] @return [Array<Arrays>]

@example paths([[1, 2], [3, 4], [5]]) #=>

  # [[1, 3, 5],
  #  [2, 3, 5],
  #  [1, 4, 5],
  #  [2, 4, 5]]

[Source]

     # File lib/haml/util.rb, line 195
195:     def paths(arrs)
196:       arrs.inject([[]]) do |paths, arr|
197:         flatten(arr.map {|e| paths.map {|path| path + [e]}}, 1)
198:       end
199:     end

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]]

@param arr [Enumerable] @return [Set<Set>] The subsets of `arr`

[Source]

     # File lib/haml/util.rb, line 99
 99:     def powerset(arr)
100:       arr.inject([Set.new].to_set) do |powerset, el|
101:         new_powerset = Set.new
102:         powerset.each do |subset|
103:           new_powerset << subset
104:           new_powerset << subset + [el]
105:         end
106:         new_powerset
107:       end
108:     end

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

@return [String, nil]

[Source]

     # File lib/haml/util.rb, line 283
283:     def rails_env
284:       return Rails.env.to_s if defined?(Rails.root)
285:       return RAILS_ENV.to_s if defined?(RAILS_ENV)
286:       return nil
287:     end

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

@return [String, nil]

[Source]

     # File lib/haml/util.rb, line 269
269:     def rails_root
270:       if defined?(Rails.root)
271:         return Rails.root.to_s if Rails.root
272:         raise "ERROR: Rails.root is nil!"
273:       end
274:       return RAILS_ROOT.to_s if defined?(RAILS_ROOT)
275:       return nil
276:     end

The class for the Rails SafeBuffer XSS protection class. This varies depending on Rails version.

@return [Class]

[Source]

     # File lib/haml/util.rb, line 381
381:     def rails_safe_buffer_class
382:       # It's important that we check ActiveSupport first,
383:       # because in Rails 2.3.6 ActionView::SafeBuffer exists
384:       # but is a deprecated proxy object.
385:       return ActiveSupport::SafeBuffer if defined?(ActiveSupport::SafeBuffer)
386:       return ActionView::SafeBuffer
387:     end

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.

@return [Boolean]

[Source]

     # File lib/haml/util.rb, line 352
352:     def rails_xss_safe?
353:       false
354:     end

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.

@param value [Numeric] @param range [Range<Numeric>] @return [Numeric]

[Source]

     # File lib/haml/util.rb, line 117
117:     def restrict(value, range)
118:       [[value, range.first].max, range.last].min
119:     end

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

@return [Boolean]

[Source]

     # File lib/haml/util.rb, line 394
394:     def ruby1_8?
395:       Haml::Util::RUBY_VERSION[0] == 1 && Haml::Util::RUBY_VERSION[1] < 9
396:     end

Whether or not this is running under Ruby 1.8.6 or lower. Note that lower versions are not officially supported.

@return [Boolean]

[Source]

     # File lib/haml/util.rb, line 402
402:     def ruby1_8_6?
403:       ruby1_8? && Haml::Util::RUBY_VERSION[2] < 7
404:     end

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

@param file [String] The filename relative to the Haml root @return [String] The filename relative to the the working directory

[Source]

    # File lib/haml/util.rb, line 22
22:     def scope(file)
23:       File.join(Haml::ROOT_DIR, file)
24:     end

Silences all Haml warnings within a block.

@yield A block in which no Haml warnings will be printed

[Source]

     # File lib/haml/util.rb, line 246
246:     def silence_haml_warnings
247:       old_silence_warnings = @@silence_warnings
248:       @@silence_warnings = true
249:       yield
250:     ensure
251:       @@silence_warnings = old_silence_warnings
252:     end

Silence all output to STDERR within a block.

@yield A block in which no output will be printed to STDERR

[Source]

     # File lib/haml/util.rb, line 235
235:     def silence_warnings
236:       the_real_stderr, $stderr = $stderr, StringIO.new
237:       yield
238:     ensure
239:       $stderr = the_real_stderr
240:     end

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

@param arr [Array] @return [Array] `arr`

[Source]

     # File lib/haml/util.rb, line 178
178:     def strip_string_array(arr)
179:       arr.first.lstrip! if arr.first.is_a?(String)
180:       arr.last.rstrip! if arr.last.is_a?(String)
181:       arr
182:     end

Substitutes a sub-array of one array with another sub-array.

@param ary [Array] The array in which to make the substitution @param from [Array] The sequence of elements to replace with `to` @param to [Array] The sequence of elements to replace `from` with

[Source]

     # File lib/haml/util.rb, line 160
160:     def substitute(ary, from, to)
161:       res = ary.dup
162:       i = 0
163:       while i < res.size
164:         if res[i...i+from.size] == from
165:           res[i...i+from.size] = to
166:         end
167:         i += 1
168:       end
169:       res
170:     end

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

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

@param arr [Array<(Object, Object)>] An array of pairs @return [Hash] A hash

[Source]

    # File lib/haml/util.rb, line 34
34:     def to_hash(arr)
35:       arr.compact.inject({}) {|h, (k, v)| h[k] = v; h}
36:     end

[Validate]