Module: Wukong::HashLike

Defined in:
lib/wukong/extensions/hash_like.rb

Overview

A hashlike has to

*

  • The arguments to your initializer should be the same as the keys, in order If not, you must override #from_hash

Defined Under Namespace

Modules: ClassMethods

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.included(base) ⇒ Object 



126
127
128
129
130
 
# File 'lib/wukong/extensions/hash_like.rb', line 126

def self.included base
  base.class_eval do
    extend ClassMethods
  end
end

Instance Method Details

#coerce_attr(attr, coerce_blank_to_nil = false, &block) ⇒ Object 



132
133
134
135
136
 
# File 'lib/wukong/extensions/hash_like.rb', line 132

def coerce_attr attr, coerce_blank_to_nil=false, &block
  orig_val = self.send(attr)
  new_val = (coerce_blank_to_nil && orig_val.blank?) ? nil : block.call(orig_val)
  self.send("#{attr}=", new_val)
end

#coerce_to_date!(attr, *args) ⇒ Object 



144
145
146
 
# File 'lib/wukong/extensions/hash_like.rb', line 144

def coerce_to_date! attr, *args
  coerce_attr(attr, *args){|val| val.is_a?(DateTime) ? val : DateTime.parse(val) rescue nil }
end

#coerce_to_int!(attr, *args) ⇒ Object 



138
139
140
141
142
 
# File 'lib/wukong/extensions/hash_like.rb', line 138

def coerce_to_int! attr, *args
  coerce_attr(attr, *args) do |val|
    val.to_i
  end
end

#compact_blank ⇒ Object

remove all key-value pairs where the value is blank



94
95
96
 
# File 'lib/wukong/extensions/hash_like.rb', line 94

def compact_blank
  to_hash.compact_blank!
end

#deep_merge(hsh2) ⇒ Object

Merge hashes recursively. Nothing special happens to array values

x = { :subhash => { 1 => :val_from_x, 222 => :only_in_x, 333 => :only_in_x }, :scalar => :scalar_from_x}
y = { :subhash => { 1 => :val_from_y, 999 => :only_in_y },                    :scalar => :scalar_from_y }
x.deep_merge y
=> {:subhash=>{1=>:val_from_y, 222=>:only_in_x, 333=>:only_in_x, 999=>:only_in_y}, :scalar=>:scalar_from_y}
y.deep_merge x
=> {:subhash=>{1=>:val_from_x, 222=>:only_in_x, 333=>:only_in_x, 999=>:only_in_y}, :scalar=>:scalar_from_x}



87
88
89
 
# File 'lib/wukong/extensions/hash_like.rb', line 87

def deep_merge hsh2
  merge hsh2, &Hash::DEEP_MERGER
end

#each_pair(*args, &block) ⇒ Object

Analagous to Hash#each_pair



59
60
61
 
# File 'lib/wukong/extensions/hash_like.rb', line 59

def each_pair *args, &block
  pairs.each(*args, &block)
end

#keys ⇒ Object

List of possible keys – delegates to the class



14
15
16
 
# File 'lib/wukong/extensions/hash_like.rb', line 14

def keys
  self.class.keys
end

#merge(*args) ⇒ Object

Analagous to Hash#merge



66
67
68
 
# File 'lib/wukong/extensions/hash_like.rb', line 66

def merge *args
  self.dup.merge!(*args)
end

#merge!(hsh, &block) ⇒ Object Also known as: update 



69
70
71
72
73
 
# File 'lib/wukong/extensions/hash_like.rb', line 69

def merge! hsh, &block
  raise "can't handle block arg yet" if block
  hsh.each_pair{|key, val| self.send("#{key}=", val) if self.respond_to?("#{key}=") }
  self
end

#pairs ⇒ Object

Analagous to Hash#each_pair



52
53
54
 
# File 'lib/wukong/extensions/hash_like.rb', line 52

def pairs
  self.class.members.map{|attr| [attr, self[attr]] }
end

#slice(*keys) ⇒ Object

Return a Hash containing only values for the given keys.

Since this is intended to mirror Hash#slice it will harmlessly ignore keys not present in the struct. They will be unset (hsh.include? is not true) as opposed to nil.



25
26
27
28
29
30
 
# File 'lib/wukong/extensions/hash_like.rb', line 25

def slice *keys
  keys.inject({}) do |hsh, key|
    hsh[key] = send(key) if respond_to?(key)
    hsh
  end
end

#to_hash ⇒ Object

Convert to a hash



45
46
47
 
# File 'lib/wukong/extensions/hash_like.rb', line 45

def to_hash
  slice(*self.class.members)
end

#values_of(*keys) ⇒ Object

values_at like a hash

Since this is intended to mirror Hash#values_at it will harmlessly ignore keys not present in the struct



38
39
40
 
# File 'lib/wukong/extensions/hash_like.rb', line 38

def values_of *keys
  keys.map{|key| self.send(key) if respond_to?(key) }
end