Class: Babosa::Identifier

Inherits:
Object
  • Object
show all
Defined in:
lib/babosa/identifier.rb

Overview

This class provides some string-manipulation methods specific to slugs.

Note that this class includes many “bang methods” such as #clean! and #normalize! that perform actions on the string in-place. Each of these methods has a corresponding “bangless” method (i.e., Identifier#clean! and Identifier#clean) which does not appear in the documentation because it is generated dynamically.

All of the bang methods return an instance of String, while the bangless versions return an instance of Babosa::Identifier, so that calls to methods specific to this class can be chained:

string = Identifier.new("hello world")
string.with_separators! # => "hello-world"
string.with_separators  # => <Babosa::Identifier:0x000001013e1590 @wrapped_string="hello-world">

See Also:

Constant Summary collapse

@@utf8_proxy = 
if Babosa.jruby15?
  UTF8::JavaProxy
elsif defined? Unicode
  UTF8::UnicodeProxy
elsif defined? ActiveSupport
  UTF8::ActiveSupportProxy
else
  UTF8::DumbProxy
end

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(string) ⇒ Identifier

Returns a new instance of Identifier.

Parameters:

  • string (#to_s) —

    The string to use as the basis of the Identifier.



53
54
55
56
57
 
# File 'lib/babosa/identifier.rb', line 53

def initialize(string)
  @wrapped_string = string.to_s
  tidy_bytes!
  normalize_utf8!
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(symbol, *args, &block) ⇒ Object 



48
49
50
 
# File 'lib/babosa/identifier.rb', line 48

def method_missing(symbol, *args, &block)
  @wrapped_string.__send__(symbol, *args, &block)
end

Instance Attribute Details

#wrapped_string ⇒ Object (readonly) Also known as: to_s

Returns the value of attribute wrapped_string.



23
24
25
 
# File 'lib/babosa/identifier.rb', line 23

def wrapped_string
  @wrapped_string
end

Class Method Details

.utf8_proxy ⇒ Object

Return the proxy used for UTF-8 support.

See Also:



38
39
40
 
# File 'lib/babosa/identifier.rb', line 38

def self.utf8_proxy
  @@utf8_proxy
end

.utf8_proxy=(obj) ⇒ Object

Set a proxy object used for UTF-8 support.

See Also:



44
45
46
 
# File 'lib/babosa/identifier.rb', line 44

def self.utf8_proxy=(obj)
  @@utf8_proxy = obj
end

Instance Method Details

#clean! ⇒ Object

Converts dashes to spaces, removes leading and trailing spaces, and replaces multiple whitespace characters with a single space.

Returns:

  • String



103
104
105
 
# File 'lib/babosa/identifier.rb', line 103

def clean!
  @wrapped_string = @wrapped_string.gsub("-", " ").squeeze(" ").strip
end

#default_normalize_options ⇒ Object

The default options for #normalize!. Override to set your own defaults.



238
239
240
 
# File 'lib/babosa/identifier.rb', line 238

def default_normalize_options
  {:transliterate => true, :max_length => 255, :separator => "-"}
end

#downcase! ⇒ Object

Perform UTF-8 sensitive downcasing.

Returns:

  • String



207
208
209
 
# File 'lib/babosa/identifier.rb', line 207

def downcase!
  @wrapped_string = @@utf8_proxy.downcase(@wrapped_string)
end

#normalize!(options = nil) ⇒ Object

Normalize the string for use as a URL slug. Note that in this context, normalize means, strip, remove non-letters/numbers, downcasing, truncating to 255 bytes and converting whitespace to dashes.

Parameters:

  • Options

Returns:

  • String



119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
 
# File 'lib/babosa/identifier.rb', line 119

def normalize!(options = nil)
  # Handle deprecated usage
  if options == true
    warn "#normalize! now takes a hash of options rather than a boolean"
    options = default_normalize_options.merge(:to_ascii => true)
  else
    options = default_normalize_options.merge(options || {})
  end
  if options[:transliterate]
    transliterate!(*options[:transliterations])
  end
  to_ascii! if options[:to_ascii]
  clean!
  word_chars!
  clean!
  downcase!
  truncate_bytes!(options[:max_length])
  with_separators!(options[:separator])
end

#normalize_utf8! ⇒ Object

Perform Unicode composition on the wrapped string.

Returns:

  • String



213
214
215
 
# File 'lib/babosa/identifier.rb', line 213

def normalize_utf8!
  @wrapped_string = @@utf8_proxy.normalize_utf8(@wrapped_string)
end

#tidy_bytes! ⇒ Object

Attempt to convert characters encoded using CP1252 and IS0-8859-1 to UTF-8.

Returns:

  • String



220
221
222
 
# File 'lib/babosa/identifier.rb', line 220

def tidy_bytes!
  @wrapped_string = @@utf8_proxy.tidy_bytes(@wrapped_string)
end

#to_ascii! ⇒ Object

Delete any non-ascii characters.

Returns:

  • String



159
160
161
 
# File 'lib/babosa/identifier.rb', line 159

def to_ascii!
  @wrapped_string = @wrapped_string.gsub(/[^\x00-\x7f]/u, '')
end

#to_identifier ⇒ Object Also known as: to_slug 



233
234
235
 
# File 'lib/babosa/identifier.rb', line 233

def to_identifier
  self
end

#to_ruby_method!(allow_bangs = true) ⇒ Object

Normalize a string so that it can safely be used as a Ruby method name.



140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
 
# File 'lib/babosa/identifier.rb', line 140

def to_ruby_method!(allow_bangs = true)
  leader, trailer = @wrapped_string.strip.scan(/\A(.+)(.)\z/).flatten
  if allow_bangs
    trailer.downcase.gsub!(/[^a-z0-9!=\\\\?]/, '')
  else
    trailer.downcase.gsub!(/[^a-z0-9]/, '')
  end
  id = leader.to_identifier
  id.transliterate!
  id.to_ascii!
  id.clean!
  id.word_chars!
  id.clean!
  @wrapped_string = id.to_s + trailer
  with_separators!("_")
end

#transliterate!(transliterations = {}) ⇒ Object Also known as: approximate_ascii!

Approximate an ASCII string. This works only for Western strings using characters that are Roman-alphabet characters + diacritics. Non-letter characters are left unmodified.

string = Identifier.new "Łódź, Poland"
string.transliterate                 # => "Lodz, Poland"
string = Identifier.new "日本"
string.transliterate                 # => "日本"

You can pass any key(s) from Characters.approximations as arguments. This allows for contextual approximations. Danish, German, Serbian and Spanish are currently supported.

string = Identifier.new "Jürgen Müller"
string.transliterate                 # => "Jurgen Muller"
string.transliterate :german         # => "Juergen Mueller"
string = Identifier.new "¡Feliz año!"
string.transliterate                 # => "¡Feliz ano!"
string.transliterate :spanish        # => "¡Feliz anio!"

You can modify the built-in approximations, or add your own:

# Make Spanish use "nh" rather than "nn"
Babosa::Characters.add_approximations(:spanish, "ñ" => "nh")

Notice that this method does not simply convert to ASCII; if you want to remove non-ASCII characters such as “¡” and “¿”, use #to_ascii!:

string.transliterate!(:spanish)       # => "¡Feliz anio!"
string.transliterate!                 # => "Feliz anio!"

Parameters:

  • *args (Symbol)

Returns:

  • String



91
92
93
94
95
96
97
98
 
# File 'lib/babosa/identifier.rb', line 91

def transliterate!(transliterations = {})
  if transliterations.kind_of? Symbol
    transliterations = Characters.approximations[transliterations]
  else
    transliterations ||= {}
  end
  @wrapped_string = unpack("U*").map { |char| approx_char(char, transliterations) }.flatten.pack("U*")
end

#truncate!(max) ⇒ Object

Truncate the string to max characters.

Examples:

"üéøá".to_identifier.truncate(3) #=> "üéø"

Returns:

  • String



167
168
169
 
# File 'lib/babosa/identifier.rb', line 167

def truncate!(max)
  @wrapped_string = unpack("U*")[0...max].pack("U*")
end

#truncate_bytes!(max) ⇒ Object

Truncate the string to max bytes. This can be useful for ensuring that a UTF-8 string will always fit into a database column with a certain max byte length. The resulting string may be less than max if the string must be truncated at a multibyte character boundary.

Examples:

"üéøá".to_identifier.truncate_bytes(3) #=> "ü"

Returns:

  • String



178
179
180
181
182
183
184
185
186
187
188
189
190
191
 
# File 'lib/babosa/identifier.rb', line 178

def truncate_bytes!(max)
  return @wrapped_string if @wrapped_string.bytesize <= max
  curr = 0
  new = []
  unpack("U*").each do |char|
    break if curr > max
    char = [char].pack("U")
    curr += char.bytesize
    if curr <= max
      new << char
    end
  end
  @wrapped_string = new.join
end

#upcase! ⇒ Object

Perform UTF-8 sensitive upcasing.

Returns:

  • String



201
202
203
 
# File 'lib/babosa/identifier.rb', line 201

def upcase!
  @wrapped_string = @@utf8_proxy.upcase(@wrapped_string)
end

#with_separators!(char = "-") ⇒ Object Also known as: with_dashes!

Replaces whitespace with dashes (“-”).

Returns:

  • String



195
196
197
 
# File 'lib/babosa/identifier.rb', line 195

def with_separators!(char = "-")
  @wrapped_string = @wrapped_string.gsub(/\s/u, char)
end

#word_chars! ⇒ Object

Remove any non-word characters. For this library’s purposes, this means anything other than letters, numbers, spaces, newlines and linefeeds.

Returns:

  • String



110
111
112
 
# File 'lib/babosa/identifier.rb', line 110

def word_chars!
  @wrapped_string = (unpack("U*") - Characters.strippable).pack("U*")
end