class

Marten::DB::Field::Polymorphic

Inherits Marten::DB::Field::Base < Reference < Object

Represents a polymorphic field.

A polymorphic field is a field that can store a reference to a record of any of the specified types:

class MyModel < Marten::Model
  # Other fields...
  field :owner, :polymorphic, to: [User, Group]
end

Constructors

new(id : ::String, id_field_id : ::String, type_field_id : ::String, to : Array(Model.class), blank = false, null = false, unique = false, index = false, related : Nil | ::String | Symbol = nil, on_delete : ::String | Symbol = :do_nothing)
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Instance methods

db_column

Returns the name of the column associated with the considered field.

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default

Returns the default value of the field if any.

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from_db(value) : Nil

Converts the raw DB value to the corresponding field value.

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from_db_result_set(result_set : ::DB::ResultSet) : Nil

Extracts the field value from a DB result set and returns the right object corresponding to this value.

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id_field_id
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on_delete
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perform_validation(record : Model)

:nodoc:

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relation?

Returns true if the field is a relation.

By default this method will always return false. It should be overridden if the field is intended to handle a relation with another model (eg. like many to one or one to one fields).

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relation_name

Returns the name of the relation on the model associated with the field.

This method will raise a NotImplementedError exception by default and should only be overridden if the #relation? method returns true (this is the case for fields such as many to one, one to one, etc).

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to_column

Returns a migration column object corresponding to the field at hand.

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to_db(value) : ::DB::Any

Converts the field value to the corresponding DB value.

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type_field_id
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