Results for: "OptionParser"

Invoked when a reference is made to an undefined constant in mod. It is passed a symbol for the undefined constant, and returns a value to be used for that constant. For example, consider:

def Foo.const_missing(name)
  name # return the constant name as Symbol
end

Foo::UNDEFINED_CONST    #=> :UNDEFINED_CONST: symbol returned

As the example above shows, const_missing is not required to create the missing constant in mod, though that is often a side-effect. The caller gets its return value when triggered. If the constant is also defined, further lookups won’t hit const_missing and will return the value stored in the constant as usual. Otherwise, const_missing will be invoked again.

In the next example, when a reference is made to an undefined constant, const_missing attempts to load a file whose path is the lowercase version of the constant name (thus class Fred is assumed to be in file fred.rb). If defined as a side-effect of loading the file, the method returns the value stored in the constant. This implements an autoload feature similar to Kernel#autoload and Module#autoload, though it differs in important ways.

def Object.const_missing(name)
  @looked_for ||= {}
  str_name = name.to_s
  raise "Constant not found: #{name}" if @looked_for[str_name]
  @looked_for[str_name] = 1
  file = str_name.downcase
  require file
  const_get(name, false)
end

Returns an array of the names of class variables in mod. This includes the names of class variables in any included modules, unless the inherit parameter is set to false.

class One
  @@var1 = 1
end
class Two < One
  @@var2 = 2
end
One.class_variables          #=> [:@@var1]
Two.class_variables          #=> [:@@var2, :@@var1]
Two.class_variables(false)   #=> [:@@var2]

Makes a list of existing constants public.

Makes a list of existing constants private.

Makes a list of existing constants deprecated. Attempt to refer to them will produce a warning.

module HTTP
  NotFound = Exception.new
  NOT_FOUND = NotFound # previous version of the library used this name

  deprecate_constant :NOT_FOUND
end

HTTP::NOT_FOUND
# warning: constant HTTP::NOT_FOUND is deprecated

Returns true if mod is a singleton class or false if it is an ordinary class or module.

class C
end
C.singleton_class?                  #=> false
C.singleton_class.singleton_class?  #=> true

Create an HTTP header block as a string.

Includes the empty line that ends the header block.

content_type_string

If this form is used, this string is the Content-Type

headers_hash

A Hash of header values. The following header keys are recognized:

type

The Content-Type header. Defaults to “text/html”

charset

The charset of the body, appended to the Content-Type header.

nph

A boolean value. If true, prepend protocol string and status code, and date; and sets default values for “server” and “connection” if not explicitly set.

status

The HTTP status code as a String, returned as the Status header. The values are:

OK

200 OK

PARTIAL_CONTENT

206 Partial Content

MULTIPLE_CHOICES

300 Multiple Choices

MOVED

301 Moved Permanently

REDIRECT

302 Found

NOT_MODIFIED

304 Not Modified

BAD_REQUEST

400 Bad Request

AUTH_REQUIRED

401 Authorization Required

FORBIDDEN

403 Forbidden

NOT_FOUND

404 Not Found

METHOD_NOT_ALLOWED

405 Method Not Allowed

NOT_ACCEPTABLE

406 Not Acceptable

LENGTH_REQUIRED

411 Length Required

PRECONDITION_FAILED

412 Precondition Failed

SERVER_ERROR

500 Internal Server Error

NOT_IMPLEMENTED

501 Method Not Implemented

BAD_GATEWAY

502 Bad Gateway

VARIANT_ALSO_VARIES

506 Variant Also Negotiates

server

The server software, returned as the Server header.

connection

The connection type, returned as the Connection header (for instance, “close”.

length

The length of the content that will be sent, returned as the Content-Length header.

language

The language of the content, returned as the Content-Language header.

expires

The time on which the current content expires, as a Time object, returned as the Expires header.

cookie

A cookie or cookies, returned as one or more Set-Cookie headers. The value can be the literal string of the cookie; a CGI::Cookie object; an Array of literal cookie strings or Cookie objects; or a hash all of whose values are literal cookie strings or Cookie objects.

These cookies are in addition to the cookies held in the @output_cookies field.

Other headers can also be set; they are appended as key: value.

Examples:

http_header
  # Content-Type: text/html

http_header("text/plain")
  # Content-Type: text/plain

http_header("nph"        => true,
            "status"     => "OK",  # == "200 OK"
              # "status"     => "200 GOOD",
            "server"     => ENV['SERVER_SOFTWARE'],
            "connection" => "close",
            "type"       => "text/html",
            "charset"    => "iso-2022-jp",
              # Content-Type: text/html; charset=iso-2022-jp
            "length"     => 103,
            "language"   => "ja",
            "expires"    => Time.now + 30,
            "cookie"     => [cookie1, cookie2],
            "my_header1" => "my_value",
            "my_header2" => "my_value")

This method does not perform charset conversion.

Returns true if the arguments define a valid commercial date, false otherwise:

Date.valid_commercial?(2001, 5, 6) # => true
Date.valid_commercial?(2001, 5, 8) # => false

See Date.commercial.

See argument start.

Related: Date.jd, Date.commercial.

Returns a copy of self with the given start value:

d0 = Date.new(2000, 2, 3)
d0.julian? # => false
d1 = d0.new_start(Date::JULIAN)
d1.julian? # => true

See argument start.

Equivalent to >> with argument n.

Equivalent to << with argument n.

Equivalent to >> with argument n * 12.

Equivalent to << with argument n * 12.

Returns a hash of the name/value pairs, to use in pattern matching. Possible keys are: :year, :month, :day, :wday, :yday.

Possible usages:

d = Date.new(2022, 10, 5)

if d in wday: 3, day: ..7  # uses deconstruct_keys underneath
  puts "first Wednesday of the month"
end
#=> prints "first Wednesday of the month"

case d
in year: ...2022
  puts "too old"
in month: ..9
  puts "quarter 1-3"
in wday: 1..5, month:
  puts "working day in month #{month}"
end
#=> prints "working day in month 10"

Note that deconstruction by pattern can also be combined with class check:

if d in Date(wday: 3, day: ..7)
  puts "first Wednesday of the month"
end

Returns a new Time object with the same value as self; if self is a Julian date, derives its Gregorian date for conversion to the Time object:

Date.new(2001, 2, 3).to_time               # => 2001-02-03 00:00:00 -0600
Date.new(2001, 2, 3, Date::JULIAN).to_time # => 2001-02-16 00:00:00 -0600

Returns a DateTime whose value is the same as self:

Date.new(2001, 2, 3).to_datetime # => #<DateTime: 2001-02-03T00:00:00+00:00>

See as_json.

Methods Date#as_json and Date.json_create may be used to serialize and deserialize a Date object; see Marshal.

Method Date#as_json serializes self, returning a 2-element hash representing self:

require 'json/add/date'
x = Date.today.as_json
# => {"json_class"=>"Date", "y"=>2023, "m"=>11, "d"=>21, "sg"=>2299161.0}

Method JSON.create deserializes such a hash, returning a Date object:

Date.json_create(x)
# => #<Date: 2023-11-21 ((2460270j,0s,0n),+0s,2299161j)>

Returns a JSON string representing self:

require 'json/add/date'
puts Date.today.to_json

Output:

{"json_class":"Date","y":2023,"m":11,"d":21,"sg":2299161.0}

Duplicates self and resets its offset.

d = DateTime.new(2001,2,3,4,5,6,'-02:00')
                          #=> #<DateTime: 2001-02-03T04:05:06-02:00 ...>
d.new_offset('+09:00')    #=> #<DateTime: 2001-02-03T15:05:06+09:00 ...>

Returns a hash of the name/value pairs, to use in pattern matching. Possible keys are: :year, :month, :day, :wday, :yday, :hour, :min, :sec, :sec_fraction, :zone.

Possible usages:

dt = DateTime.new(2022, 10, 5, 13, 30)

if d in wday: 1..5, hour: 10..18  # uses deconstruct_keys underneath
  puts "Working time"
end
#=> prints "Working time"

case dt
in year: ...2022
  puts "too old"
in month: ..9
  puts "quarter 1-3"
in wday: 1..5, month:
  puts "working day in month #{month}"
end
#=> prints "working day in month 10"

Note that deconstruction by pattern can also be combined with class check:

if d in DateTime(wday: 1..5, hour: 10..18, day: ..7)
  puts "Working time, first week of the month"
end

Returns a Time object which denotes self.

Returns self.

See as_json.

Methods DateTime#as_json and DateTime.json_create may be used to serialize and deserialize a DateTime object; see Marshal.

Method DateTime#as_json serializes self, returning a 2-element hash representing self:

require 'json/add/datetime'
x = DateTime.now.as_json
# => {"json_class"=>"DateTime", "y"=>2023, "m"=>11, "d"=>21, "sg"=>2299161.0}

Method JSON.create deserializes such a hash, returning a DateTime object:

DateTime.json_create(x) # BUG? Raises Date::Error "invalid date"