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require 'delegate'
begin
require 'rubygems'
gem 'deprecated'
rescue LoadError => e
end
require 'deprecated'
module DBI
# This represents metadata for columns within a given table, such as the
# data type, whether or not the the column is a primary key, etc.
#
# ColumnInfo is a delegate of Hash, but represents its keys indifferently,
# coercing all strings to symbols. It also has ostruct-like features, f.e.:
#
# h = ColumnInfo.new({ "foo" => "bar" })
# h[:foo] => "bar"
# h["foo"] => "bar"
# h.foo => "bar"
#
# All of these forms have assignment forms as well.
#
class ColumnInfo < DelegateClass(Hash)
# Create a new ColumnInfo object.
#
# If no Hash is provided, one will be created for you. The hash will be
# shallow cloned for storage inside the object, and an attempt will be
# made to convert all string keys to symbols.
#
# In the event that both string and symbol keys are provided in the
# initial hash, we cannot safely route around collisions and therefore
# a TypeError is raised.
#
def initialize(hash=nil)
@hash = hash.dup rescue nil
@hash ||= Hash.new
# coerce all strings to symbols
@hash.each_key do |x|
if x.kind_of? String
sym = x.to_sym
if @hash.has_key? sym
raise ::TypeError,
"#{self.class.name} may construct from a hash keyed with strings or symbols, but not both"
end
@hash[sym] = @hash[x]
@hash.delete(x)
end
end
super(@hash)
end
def [](key)
@hash[key.to_sym]
end
def []=(key, value)
@hash[key.to_sym] = value
end
def default() # :nodoc; XXX hack to get around Hash#default
method_missing(:default)
end
def method_missing(sym, value=nil)
if sym.to_s =~ /=$/
sym = sym.to_s.sub(/=$/, '').to_sym
@hash[sym] = value
elsif sym.to_s =~ /\?$/
sym = sym.to_s.sub(/\?$/, '').to_sym
@hash[sym]
else
@hash[sym]
end
end
# Aliases - XXX soon to be deprecated
def self.deprecated_alias(target, source) # :nodoc:
define_method(target) { |*args| method_missing(source, *args) }
deprecate target
end
deprecated_alias :is_nullable?, :nullable
deprecated_alias :can_be_null?, :nullable
deprecated_alias :is_indexed?, :indexed
deprecated_alias :is_primary?, :primary
deprecated_alias :is_unique, :unique
deprecated_alias :size, :precision
deprecated_alias :size=, :precision=
deprecated_alias :length, :precision
deprecated_alias :length=, :precision=
deprecated_alias :decimal_digits, :scale
deprecated_alias :decimal_digits=, :scale=
deprecated_alias :default_value, :default
deprecated_alias :default_value=, :default=
end
end
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