Class: Portrayal::Schema

Inherits:
Object
  • Object
show all
Defined in:
lib/portrayal/schema.rb

Constant Summary collapse

NULL = 
Object.new.freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Schema

Returns a new instance of Schema.



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# File 'lib/portrayal/schema.rb', line 7

def initialize;       @schema = {}; @module = Module.new                end

Instance Attribute Details

#module ⇒ Object (readonly)

Returns the value of attribute module.



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# File 'lib/portrayal/schema.rb', line 4

def module
  @module
end

#schema ⇒ Object (readonly)

Returns the value of attribute schema.



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# File 'lib/portrayal/schema.rb', line 4

def schema
  @schema
end

Instance Method Details

#add_keyword(name, default) ⇒ Object 



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# File 'lib/portrayal/schema.rb', line 18

def add_keyword(name, default)
  name = name.to_sym
  @schema.delete(name) # Forcing keyword to be added at the end of the hash.
  @schema[name] = default.equal?(NULL) ? nil : Portrayal::Default.new(default)
  @module.module_eval(render_module_code)
end

#attributes(obj) ⇒ Object 



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# File 'lib/portrayal/schema.rb', line 9

def attributes(obj);  Hash[keywords.map { |k| [k, obj.send(k)] }]       end

#camelize(string) ⇒ Object 



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# File 'lib/portrayal/schema.rb', line 10

def camelize(string); string.to_s.gsub(/(?:^|_+)([^_])/) { $1.upcase }  end

#initialize_dup(src) ⇒ Object 



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# File 'lib/portrayal/schema.rb', line 12

def initialize_dup(src)
  @schema = src.schema.transform_values(&:dup)
  @module = src.module.dup
  super
end

#keywords ⇒ Object 



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# File 'lib/portrayal/schema.rb', line 8

def keywords;         @schema.keys                                      end

#render_module_code ⇒ Object 



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# File 'lib/portrayal/schema.rb', line 25

def render_module_code
  args, inits, syms, hash, eqls, dups, clones, setters, freezes =
    '', '', '', '', '', '', '', '', ''

  @schema.each do |k, default|
    args  << "#{k}:#{default && " self.class.portrayal.schema[:#{k}]"}, "
    inits << "@#{k} = #{k}.is_a?(::Portrayal::Default) ? #{k}.(self) : #{k}; "
    syms  << ":#{k}, "
    hash  << "#{k}: @#{k}, "
    eqls  << "@#{k} == other.instance_variable_get('@#{k}') && "
    dups  << "@#{k} = src.instance_variable_get('@#{k}').dup; "
    clones  << "@#{k} = src.instance_variable_get('@#{k}').clone; "
    setters << ":#{k}=, "
    freezes << "@#{k}.freeze; "
  end

  args.chomp!(', ')    # key1:, key2: self.class.portrayal.schema[:key2]
  inits.chomp!('; ')   # Assignments in initialize
  syms.chomp!(', ')    # :key1, :key2
  hash.chomp!(', ')    # key1: @key1, key2: @key2
  eqls.chomp!(' && ')  # @key1 == other.instance_variable_get('@key1') &&
  dups.chomp!('; ')    # @key1 = src.instance_variable_get('@key1').dup;
  clones.chomp!('; ')  # @key1 = src.instance_variable_get('@key1').clone;
  setters.chomp!(', ') # :key1=, :key2=
  freezes.chomp!('; ') # @key1.freeze; @key2.freeze

  <<-RUBY
attr_accessor #{syms}
protected #{setters}
def initialize(#{args}); #{inits} end
def hash; [self.class, {#{hash}}].hash end
def ==(other); self.class == other.class && #{eqls} end
alias eql? ==
def freeze; #{freezes}; super end
def initialize_dup(src); #{dups}; super end
def initialize_clone(src); #{clones}; super end
def deconstruct
public_syms = [#{syms}].select { |s| self.class.public_method_defined?(s) }
public_syms.map { |s| public_send(s) }
end
def deconstruct_keys(keys)
filtered_keys = [#{syms}].select {|s| self.class.public_method_defined?(s) }
filtered_keys &= keys if Array === keys
Hash[filtered_keys.map { |k| [k, public_send(k)] }]
end
  RUBY
end