Class: Hash

Inherits:
Object
  • Object
show all
Defined in:
lib/rets4r/core_ext/hash/keys.rb,
lib/rets4r/core_ext/hash/slice.rb

Overview

from ActiveSupport

Instance Method Summary collapse

Instance Method Details

#assert_valid_keys(*valid_keys) ⇒ Object

Validate all keys in a hash match *valid keys, raising ArgumentError on a mismatch. Note that keys are NOT treated indifferently, meaning if you use strings for keys but assert symbols as keys, this will fail.

Examples

{ :name => "Rob", :years => "28" }.assert_valid_keys(:name, :age) # => raises "ArgumentError: Unknown key(s): years"
{ :name => "Rob", :age => "28" }.assert_valid_keys("name", "age") # => raises "ArgumentError: Unknown key(s): name, age"
{ :name => "Rob", :age => "28" }.assert_valid_keys(:name, :age) # => passes, raises nothing

Raises:

  • (ArgumentError) 


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# File 'lib/rets4r/core_ext/hash/keys.rb', line 42

def assert_valid_keys(*valid_keys)
  unknown_keys = keys - [valid_keys].flatten
  raise(ArgumentError, "Unknown key(s): #{unknown_keys.join(", ")}") unless unknown_keys.empty?
end

#extract!(*keys) ⇒ Object 



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# File 'lib/rets4r/core_ext/hash/slice.rb', line 34

def extract!(*keys)
  result = {}
  keys.each {|key| result[key] = delete(key) }
  result
end

#slice(*keys) ⇒ Object

Slice a hash to include only the given keys. This is useful for limiting an options hash to valid keys before passing to a method:

def search(criteria = {})
  assert_valid_keys(:mass, :velocity, :time)
end

search(options.slice(:mass, :velocity, :time))

If you have an array of keys you want to limit to, you should splat them:

valid_keys = [:mass, :velocity, :time]
search(options.slice(*valid_keys))



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# File 'lib/rets4r/core_ext/hash/slice.rb', line 16

def slice(*keys)
  keys = keys.map! { |key| convert_key(key) } if respond_to?(:convert_key)
  hash = self.class.new
  keys.each { |k| hash[k] = self[k] if has_key?(k) }
  hash
end

#slice!(*keys) ⇒ Object

Replaces the hash with only the given keys. Returns a hash contained the removed key/value pairs

{:a => 1, :b => 2, :c => 3, :d => 4}.slice!(:a, :b) # => {:c => 3, :d =>4}



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# File 'lib/rets4r/core_ext/hash/slice.rb', line 26

def slice!(*keys)
  keys = keys.map! { |key| convert_key(key) } if respond_to?(:convert_key)
  omit = slice(*self.keys - keys)
  hash = slice(*keys)
  replace(hash)
  omit
end

#stringify_keys ⇒ Object

Return a new hash with all keys converted to strings.



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# File 'lib/rets4r/core_ext/hash/keys.rb', line 4

def stringify_keys
  dup.stringify_keys!
end

#stringify_keys! ⇒ Object

Destructively convert all keys to strings.



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# File 'lib/rets4r/core_ext/hash/keys.rb', line 9

def stringify_keys!
  keys.each do |key|
    self[key.to_s] = delete(key)
  end
  self
end

#symbolize_keys ⇒ Object Also known as: to_options

Return a new hash with all keys converted to symbols, as long as they respond to to_sym.



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# File 'lib/rets4r/core_ext/hash/keys.rb', line 18

def symbolize_keys
  dup.symbolize_keys!
end

#symbolize_keys! ⇒ Object Also known as: to_options!

Destructively convert all keys to symbols, as long as they respond to to_sym.



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# File 'lib/rets4r/core_ext/hash/keys.rb', line 24

def symbolize_keys!
  keys.each do |key|
    self[(key.to_sym rescue key) || key] = delete(key)
  end
  self
end