class Hashery::QueryHash

QueryHash is essentially a Hash class, but with some OpenStruct-like features.

q = QueryHash.new

Entries can be added to the Hash via a setter method.

q.a = 1

Then looked up via a query method.

q.a?  #=> 1

The can also be looked up via a bang method.

q.a!  #=> 1

The difference between query methods and bang methods is that the bang method will auto-instantiate the entry if not present, where as a query method will not.

A QueryHash might not be quite as elegant as an OpenHash in that reader methods must end in ‘?` or `!`, but it remains fully compatible with Hash regardless of it’s settings.

Public Class Methods

new(*default, &default_proc) click to toggle source

By default the ‘key_proc` is set to convert all keys to strings via `#to_s`.

default - Default object, or default_proc - Default procedure.

Calls superclass method
# File lib/hashery/query_hash.rb, line 36
def initialize(*default, &default_proc)
  @key_proc = Proc.new{ |k| k.to_s }
  super(*default, &default_proc)
end

Public Instance Methods

method_missing(s,*a, &b) click to toggle source

Route get and set calls.

s - [Symbol] Name of method. a - [Array] Method arguments. b - [Proc] Block argument.

Examples

o = QueryHash.new
o.a = 1
o.a?  #=> 1
o.b?  #=> nil
Calls superclass method
# File lib/hashery/query_hash.rb, line 55
def method_missing(s,*a, &b)
  type = s.to_s[-1,1]
  name = s.to_s.sub(/[!?=]$/, '')     
  key  = name  #key  = cast_key(name)

  case type
  when '='
    store(key, a.first)
  when '!'
    default = (default_proc ? default_proc.call(self, key) : default)
    key?(key) ?  fetch(key) : store(key, default)
  when '?'
    key?(key) ? fetch(key) : nil
  else
    # return self[key] if key?(key)
    super(s,*a,&b)
  end
end
respond_to?(name) click to toggle source

Custom respond_to to account for method_missing.

name - The method name to check.

Returns ‘true` or `false`.

Calls superclass method
# File lib/hashery/query_hash.rb, line 81
def respond_to?(name)
  return true if name.to_s.end_with?('=')
  return true if name.to_s.end_with?('?')
  return true if name.to_s.end_with?('!')
  #key?(name.to_sym) || super(name)
  super(name)
end