Class: Pod4::BasicModel

Inherits:
Object
  • Object
show all
Extended by:
Metaxing
Defined in:
lib/pod4/basic_model.rb

Overview

The ultimate parent of all models. It has an interface, an id, a status, and alerts. That’s pretty much it.

This is useful to the user for weirder models – for example, where the datasource records and the model instances don’t map one-to-one.

See Pod4::Model for documentation about Models.

Direct Known Subclasses

Model

Constant Summary collapse

STATII =

Valid values for @model_status: :error :warning :okay :deleted or :unknown

%i|error warning okay deleted empty|

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Metaxing

define_class_method, metaclass

Constructor Details

#initialize(id = nil) ⇒ BasicModel

Initialize a model by passing it a unique id value. Override this to set initial values for your column attributes.



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# File 'lib/pod4/basic_model.rb', line 51

def initialize(id=nil)
  @model_status = :unknown
  @model_id     = id
  @alerts       = []
end

Instance Attribute Details

#model_id ⇒ Object (readonly)

The value of the ID field on the record



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# File 'lib/pod4/basic_model.rb', line 24

def model_id
  @model_id
end

#model_status ⇒ Object (readonly)

one of Model::STATII



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# File 'lib/pod4/basic_model.rb', line 27

def model_status
  @model_status
end

Class Method Details

.interface ⇒ Object

Raises:



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# File 'lib/pod4/basic_model.rb', line 41

def interface
  raise NotImplemented, "no call to set_interface in the model"
end

.set_interface(interface) ⇒ Object

You MUST call this in your model definition to give it an instance of an interface.



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# File 'lib/pod4/basic_model.rb', line 37

def set_interface(interface)
  define_class_method(:interface) {interface}
end

Instance Method Details

#alerts ⇒ Object

Return the list of alerts.

We don’t use attr_reader for this because it won’t protect an array from external changes.



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# File 'lib/pod4/basic_model.rb', line 67

def alerts; @alerts.dup; end

#clear_alerts ⇒ Object

Clear down the alerts.

Note that we set model_status to :okay. Theoretically it might need to be :unknown or :deleted, but if you are calling clear_alerts before a call to ‘read` or after a call to `delete`, then you have more problems than I can solve.



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# File 'lib/pod4/basic_model.rb', line 76

def clear_alerts
  @alerts       = []
  @model_status = :okay
end

#interface ⇒ Object

Syntactic sugar; same as self.class.interface, which returns the interface instance.



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# File 'lib/pod4/basic_model.rb', line 60

def interface; self.class.interface; end

#raise_exceptions ⇒ Object Also known as: or_die

Raise a Pod4 exception for the model if any alerts are status :error; otherwise do nothing.

Note the alias of or_die for this method, which means that if you have kept to the idiom of CRUD methods returning self, then you can steal a lick from Perl and say:

MyModel.new(14).read.or_die



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# File 'lib/pod4/basic_model.rb', line 90

def raise_exceptions
  al = @alerts.sort.first
  raise ValidationError.from_alert(al) if al && al.type == :error
  self
end