Class: String

Inherits:
Object
  • Object
show all
Defined in:
lib/i18n/string.rb

Overview

Extension for String class. This feature is included in Ruby 1.9 or later but not occur TypeError.

String#% method which accept “named argument”. The translator can know the meaning of the msgids using “named argument” instead of %s/%d style.

Constant Summary collapse

INTERPOLATION_PATTERN = 
Regexp.union(
  /%%/,
  /%\{(\w+)\}/,                               # matches placeholders like "%{foo}"
  /%<(\w+)>(.*?\d*\.?\d*[bBdiouxXeEfgGcps])/  # matches placeholders like "%<foo>.d"
)

Instance Method Summary collapse

Instance Method Details

#%(args) ⇒ Object

% uses self (i.e. the String) as a format specification and returns the result of applying it to the given arguments. In other words it interpolates the given arguments to the string according to the formats the string defines.

There are three ways to use it:

  • Using a single argument or Array of arguments.

    This is the default behaviour of the String class. See Kernel#sprintf for more details about the format string.

    Example:

    "%d %s" % [1, "message"]
# => "1 message"

  • Using a Hash as an argument and unformatted, named placeholders.

    When you pass a Hash as an argument and specify placeholders with %foo it will interpret the hash values as named arguments.

    Example:

    "%{firstname}, %{lastname}" % {:firstname => "Masao", :lastname => "Mutoh"}
# => "Masao Mutoh"

  • Using a Hash as an argument and formatted, named placeholders.

    When you pass a Hash as an argument and specify placeholders with %<foo>d it will interpret the hash values as named arguments and format the value according to the formatting instruction appended to the closing >.

    Example:

    "%<integer>d, %<float>.1f" % { :integer => 10, :float => 43.4 }
# => "10, 43.3"



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# File 'lib/i18n/string.rb', line 74

def %(args)
  if args.kind_of?(Hash)
    dup.gsub(INTERPOLATION_PATTERN) do |match|
      if match == '%%'
        '%'
      else
        key = ($1 || $2).to_sym
        raise KeyError unless args.has_key?(key)
        $3 ? sprintf("%#{$3}", args[key]) : args[key]
      end
    end
  elsif self =~ INTERPOLATION_PATTERN
    raise ArgumentError.new('one hash required')
  else
    result = gsub(/%([{<])/, '%%\1')
    result.send :'interpolate_without_ruby_19_syntax', args
  end
end

#interpolate_without_ruby_19_syntax ⇒ Object

:nodoc:



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# File 'lib/i18n/string.rb', line 29

alias :interpolate_without_ruby_19_syntax :%