Module: Fusu::String::Methods

Included in:
Fusu::String
Defined in:
lib/fusu/string/methods.rb

Constant Summary collapse

ACRONYM_REGEX = 
/(?=a)b/

Instance Method Summary collapse

Instance Method Details

#camelize(term, uppercase_first_letter = true) ⇒ Object

Converts strings to UpperCamelCase. If the uppercase_first_letter parameter is set to false, then produces lowerCamelCase.

Also converts ‘/’ to ‘::’ which is useful for converting paths to namespaces.

camelize('active_model')                # => "ActiveModel"
camelize('active_model', false)         # => "activeModel"
camelize('active_model/errors')         # => "ActiveModel::Errors"
camelize('active_model/errors', false)  # => "activeModel::Errors"

As a rule of thumb you can think of camelize as the inverse of #underscore, though there are cases where that does not hold:

camelize(underscore('SSLError'))        # => "SslError"



33
34
35
36
37
38
39
40
41
42
43
 
# File 'lib/fusu/string/methods.rb', line 33

def camelize(term, uppercase_first_letter = true)
  string = term.to_s
  if uppercase_first_letter
    string = string.sub(/^[a-z\d]*/) { |match| match.capitalize }
  else
    string = string.sub(/^(?:#{ACRONYM_REGEX}(?=\b|[A-Z_])|\w)/) { |match| match.downcase }
  end
  string.gsub!(/(?:_|(\/))([a-z\d]*)/i) { "#{$1}#{$2.capitalize}" }
  string.gsub!("/".freeze, "::".freeze)
  string
end

#constantize(camel_cased_word) ⇒ Object

Tries to find a constant with the name specified in the argument string.

constantize('Module')   # => Module
constantize('Foo::Bar') # => Foo::Bar

The name is assumed to be the one of a top-level constant, no matter whether it starts with “::” or not. No lexical context is taken into account:

C = 'outside'
module M
  C = 'inside'
  C                # => 'inside'
  constantize('C') # => 'outside', same as ::C
end

NameError is raised when the name is not in CamelCase or the constant is unknown.



211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
 
# File 'lib/fusu/string/methods.rb', line 211

def constantize(camel_cased_word)
  names = camel_cased_word.split("::".freeze)

  # Trigger a built-in NameError exception including the ill-formed constant in the message.
  Object.const_get(camel_cased_word) if names.empty?

  # Remove the first blank element in case of '::ClassName' notation.
  names.shift if names.size > 1 && names.first.empty?

  names.inject(Object) do |constant, name|
    if constant == Object
      constant.const_get(name)
    else
      candidate = constant.const_get(name)
      next candidate if constant.const_defined?(name, false)
      next candidate unless Object.const_defined?(name)

      # Go down the ancestors to check if it is owned directly. The check
      # stops when we reach Object or the end of ancestors tree.
      constant = constant.ancestors.inject(constant) do |const, ancestor|
        break const    if ancestor == Object
        break ancestor if ancestor.const_defined?(name, false)
        const
      end

      # owner is in Object, so raise
      constant.const_get(name, false)
    end
  end
end

#dasherize(underscored_word) ⇒ Object

Replaces underscores with dashes in the string.

dasherize('puni_puni') # => "puni-puni"



148
149
150
 
# File 'lib/fusu/string/methods.rb', line 148

def dasherize(underscored_word)
  underscored_word.tr("_".freeze, "-".freeze)
end

#deconstantize(path) ⇒ Object

Removes the rightmost segment from the constant expression in the string.

deconstantize('Net::HTTP')   # => "Net"
deconstantize('::Net::HTTP') # => "::Net"
deconstantize('String')      # => ""
deconstantize('::String')    # => ""
deconstantize('')            # => ""

See also #demodulize.



178
179
180
 
# File 'lib/fusu/string/methods.rb', line 178

def deconstantize(path)
  path.to_s[0, path.rindex("::") || 0] # implementation based on the one in facets' Module#spacename
end

#demodulize(path) ⇒ Object

Removes the module part from the expression in the string.

demodulize('ActiveSupport::Inflector::Inflections') # => "Inflections"
demodulize('Inflections')                           # => "Inflections"
demodulize('::Inflections')                         # => "Inflections"
demodulize('')                                      # => ""

See also #deconstantize.



160
161
162
163
164
165
166
167
 
# File 'lib/fusu/string/methods.rb', line 160

def demodulize(path)
  path = path.to_s
  if i = path.rindex("::")
    path[(i + 2)..-1]
  else
    path
  end
end

#foreign_key(class_name, separate_class_name_and_id_with_underscore = true) ⇒ Object

Creates a foreign key name from a class name. separate_class_name_and_id_with_underscore sets whether the method should put ‘_’ between the name and ‘id’.

foreign_key('Message')        # => "message_id"
foreign_key('Message', false) # => "messageid"
foreign_key('Admin::Post')    # => "post_id"



189
190
191
 
# File 'lib/fusu/string/methods.rb', line 189

def foreign_key(class_name, separate_class_name_and_id_with_underscore = true)
  underscore(demodulize(class_name)) + (separate_class_name_and_id_with_underscore ? "_id" : "id")
end

#humanize(lower_case_and_underscored_word, capitalize: true, keep_id_suffix: false) ⇒ Object

Tweaks an attribute name for display to end users.

Specifically, performs these transformations:

  • Applies human inflection rules to the argument.

  • Deletes leading underscores, if any.

  • Removes a “_id” suffix if present.

  • Replaces underscores with spaces, if any.

  • Downcases all words except acronyms.

  • Capitalizes the first word.

The capitalization of the first word can be turned off by setting the :capitalize option to false (default is true).

The trailing ‘_id’ can be kept and capitalized by setting the optional parameter keep_id_suffix to true (default is false).

humanize('employee_salary')                  # => "Employee salary"
humanize('author_id')                        # => "Author"
humanize('author_id', capitalize: false)     # => "author"
humanize('_id')                              # => "Id"
humanize('author_id', keep_id_suffix: true)  # => "Author Id"

If “SSL” was defined to be an acronym:

humanize('ssl_error') # => "SSL error"



102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
 
# File 'lib/fusu/string/methods.rb', line 102

def humanize(lower_case_and_underscored_word, capitalize: true, keep_id_suffix: false)
  result = lower_case_and_underscored_word.to_s.dup

  # inflections.humans.each { |(rule, replacement)| break if result.sub!(rule, replacement) }

  result.sub!(/\A_+/, "".freeze)
  unless keep_id_suffix
    result.sub!(/_id\z/, "".freeze)
  end
  result.tr!("_".freeze, " ".freeze)

  result.gsub!(/([a-z\d]*)/i) do |match|
    "#{match.downcase}"
  end

  if capitalize
    result.sub!(/\A\w/) { |match| match.upcase }
  end

  result
end

#ordinal(number) ⇒ Object

Returns the suffix that should be added to a number to denote the position in an ordered sequence such as 1st, 2nd, 3rd, 4th.

ordinal(1)     # => "st"
ordinal(2)     # => "nd"
ordinal(1002)  # => "nd"
ordinal(1003)  # => "rd"
ordinal(-11)   # => "th"
ordinal(-1021) # => "st"



282
283
284
285
286
287
288
289
290
291
292
293
294
295
 
# File 'lib/fusu/string/methods.rb', line 282

def ordinal(number)
  abs_number = number.to_i.abs

  if (11..13).include?(abs_number % 100)
    "th"
  else
    case abs_number % 10
    when 1; "st"
    when 2; "nd"
    when 3; "rd"
      else    "th"
    end
  end
end

#ordinalize(number) ⇒ Object

Turns a number into an ordinal string used to denote the position in an ordered sequence such as 1st, 2nd, 3rd, 4th.

ordinalize(1)     # => "1st"
ordinalize(2)     # => "2nd"
ordinalize(1002)  # => "1002nd"
ordinalize(1003)  # => "1003rd"
ordinalize(-11)   # => "-11th"
ordinalize(-1021) # => "-1021st"



306
307
308
 
# File 'lib/fusu/string/methods.rb', line 306

def ordinalize(number)
  "#{number}#{ordinal(number)}"
end

#safe_constantize(camel_cased_word) ⇒ Object

Tries to find a constant with the name specified in the argument string.

safe_constantize('Module')   # => Module
safe_constantize('Foo::Bar') # => Foo::Bar

The name is assumed to be the one of a top-level constant, no matter whether it starts with “::” or not. No lexical context is taken into account:

C = 'outside'
module M
  C = 'inside'
  C                     # => 'inside'
  safe_constantize('C') # => 'outside', same as ::C
end

nil is returned when the name is not in CamelCase or the constant (or part of it) is unknown.

safe_constantize('blargle')                  # => nil
safe_constantize('UnknownModule')            # => nil
safe_constantize('UnknownModule::Foo::Bar')  # => nil



264
265
266
267
268
269
270
271
 
# File 'lib/fusu/string/methods.rb', line 264

def safe_constantize(camel_cased_word)
  constantize(camel_cased_word)
rescue NameError => e
  raise if e.name && !(camel_cased_word.to_s.split("::").include?(e.name.to_s) ||
    e.name.to_s == camel_cased_word.to_s)
rescue ArgumentError => e
  raise unless /not missing constant #{const_regexp(camel_cased_word)}!$/.match?(e.message)
end

#titleize(word, keep_id_suffix: false) ⇒ Object

Capitalizes all the words and replaces some characters in the string to create a nicer looking title. titleize is meant for creating pretty output. It is not used in the Rails internals.

The trailing ‘_id’,‘Id’.. can be kept and capitalized by setting the optional parameter keep_id_suffix to true. By default, this parameter is false.

titleize is also aliased as titlecase.

titleize('man from the boondocks')                       # => "Man From The Boondocks"
titleize('x-men: the last stand')                        # => "X Men: The Last Stand"
titleize('TheManWithoutAPast')                           # => "The Man Without A Past"
titleize('raiders_of_the_lost_ark')                      # => "Raiders Of The Lost Ark"
titleize('string_ending_with_id', keep_id_suffix: true)  # => "String Ending With Id"



139
140
141
142
143
 
# File 'lib/fusu/string/methods.rb', line 139

def titleize(word, keep_id_suffix: false)
  humanize(underscore(word), keep_id_suffix: keep_id_suffix).gsub(/\b(?<!\w['’`])[a-z]/) do |match|
    match.capitalize
  end
end

#underscore(camel_cased_word) ⇒ Object

Makes an underscored, lowercase form from the expression in the string.

Changes ‘::’ to ‘/’ to convert namespaces to paths.

underscore('ActiveModel')         # => "active_model"
underscore('ActiveModel::Errors') # => "active_model/errors"

As a rule of thumb you can think of underscore as the inverse of #camelize, though there are cases where that does not hold:

camelize(underscore('SSLError'))  # => "SslError"



56
57
58
59
60
61
62
63
64
65
 
# File 'lib/fusu/string/methods.rb', line 56

def underscore(camel_cased_word)
  return camel_cased_word unless Fusu::Regexp.match?(/[A-Z-]|::/, camel_cased_word)
  word = camel_cased_word.to_s.gsub("::".freeze, "/".freeze)
  word.gsub!(/(?:(?<=([A-Za-z\d]))|\b)(#{ACRONYM_REGEX})(?=\b|[^a-z])/) { "#{$1 && '_'.freeze }" }
  word.gsub!(/([A-Z\d]+)([A-Z][a-z])/, '\1_\2'.freeze)
  word.gsub!(/([a-z\d])([A-Z])/, '\1_\2'.freeze)
  word.tr!("-".freeze, "_".freeze)
  word.downcase!
  word
end

#upcase_first(string) ⇒ Object

Converts just the first character to uppercase.

upcase_first('what a Lovely Day') # => "What a Lovely Day"
upcase_first('w')                 # => "W"
upcase_first('')                  # => ""



72
73
74
 
# File 'lib/fusu/string/methods.rb', line 72

def upcase_first(string)
  string.length > 0 ? string[0].upcase.concat(string[1..-1]) : ""
end