Module: Tableless::InstanceMethods

Included in:
ActiveRecord::TablelessModel
Defined in:
lib/tableless_model/instance_methods.rb

Instance Method Summary collapse

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(sym, *args, &block) ⇒ Object

allows calls to attribute_name?, returning a true or false depending on whether the actual value of the attribute is truthy or falsy



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# File 'lib/tableless_model/instance_methods.rb', line 97

def method_missing sym, *args, &block
  attribute_name = sym.to_s.gsub(/^(.*)\?$/, "\\1")
  if respond_to?(attribute_name)
    !!send(attribute_name, *args, &block) 
  else
    super sym, *args, &block
  end
end

Instance Method Details

#[](attribute_name) ⇒ Object

Overriding getter for the underlying hash keys so that only the defined attributes can be read

Raises:

  • (NoMethodError) 


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# File 'lib/tableless_model/instance_methods.rb', line 36

def [](attribute_name)
  raise NoMethodError, "The attribute #{attribute_name} is undefined" unless self.class.attributes.has_key? attribute_name
  default = super(attribute_name)
  self.class.cast(attribute_name, default.is_a?(Proc) ? default.call : default)
end

#[]=(attribute_name, value) ⇒ Object

Overriding setter for the underlying hash keys so that only the defined attributes can be set

Raises:

  • (NoMethodError) 


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# File 'lib/tableless_model/instance_methods.rb', line 48

def []=(attribute_name, value)
  raise NoMethodError, "The attribute #{attribute_name} is undefined" unless self.class.attributes.has_key? attribute_name
  
  return_value = super(attribute_name, self.class.cast(attribute_name, value))

  if self.__owner_object 
    # This makes the tableless model compatible with partial_updates:
    # whenever a property in the tableless model is changed, we force the parent/owner object to a changed state
    # by updating it with a new, updated instance of the tableless model
    self.__owner_object.send "#{self.__serialized_attribute.to_s}=".to_sym, self
  end

  return_value
end

#initialize(init_attributes = {}, &block) ⇒ Object

On initialising an instance of a tableless model, sets the default values for all the attributes defined. Optionally, initialises the tableless model with the values specified as arguments, instead, overriding the default values



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# File 'lib/tableless_model/instance_methods.rb', line 12

def initialize(init_attributes = {}, &block)
  super &block

  self.class.attributes.each_pair {|attribute_name, options| self.send("#{attribute_name}=".to_sym, options[:default].is_a?(Proc) ? options[:default].call : options[:default])}
  init_attributes.each_pair {|k,v| self[k] = v } if init_attributes
end

#inspect ⇒ Object

The Hash object displays inspect information in the format

"{:a=>1, :b=>2}"

to make the tableless model look a bit more like regular models, it shows instead the inspect information in this format:

"<#MyTablelessModel a=1 b=2>"



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# File 'lib/tableless_model/instance_methods.rb', line 75

def inspect
  "<##{self.class.to_s}" << self.keys.sort{ |a,b| a.to_s <=> b.to_s  }.inject("") do |result, k| 
    result += " #{k}=#{ self[k].is_a?(Time) ? self[k].strftime("%Y-%m-%d %H:%M:%S %Z") : self[k].inspect}"
    result 
  end + ">"
end

#merge(hash) ⇒ Object

Since the object should only allow the defined attributes merging is forbidden

Raises:

  • (NoMethodError) 


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# File 'lib/tableless_model/instance_methods.rb', line 88

def merge(hash)
  raise NoMethodError
end

#respond_to?(method) ⇒ Boolean

Returns true if the method name specified corresponds to the key of an attribute defined for the tableless model

Returns:

  • (Boolean) 


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# File 'lib/tableless_model/instance_methods.rb', line 26

def respond_to?(method_name)
  key?(method_name) ? true : super
end