from django.db import models

from construct import Construct


class Typed (Construct, models.Model):

    """Indicates that a Topic Maps construct is typed. `Association`s,
    `Role`s, `Occurrence`s, and `Name`s are typed."""

    type = models.ForeignKey('Topic', related_name='typed_%(class)ss')
    
    class Meta:
        abstract = True
        app_label = 'tmapi'
    
    def get_type (self):
        """Returns the type of this construct.

        :rtype: the `Topic` that represents the type

        """
        return self.type

    def set_type (self, construct_type):
        """Sets the type of this construct. Any previous type is overridden.

        :param construct_type: the `Topic` that should define the
          nature of this construct

        """
        self.type = construct_type
        self.save()

from django.db import models

from tmapi.exceptions import ModelConstraintException

from construct import Construct


class Typed (Construct, models.Model):

    """Indicates that a Topic Maps construct is typed. `Association`s,
    `Role`s, `Occurrence`s, and `Name`s are typed."""

    type = models.ForeignKey('Topic', related_name='typed_%(class)ss')
    
    class Meta:
        abstract = True
        app_label = 'tmapi'
    
    def get_type (self):
        """Returns the type of this construct.

        :rtype: the `Topic` that represents the type

        """
        return self.type

    def set_type (self, construct_type):
        """Sets the type of this construct. Any previous type is overridden.

        :param construct_type: the `Topic` that should define the
          nature of this construct

        """
        if construct_type is None:
            raise ModelConstraintException
        self.type = construct_type
        self.save()

Raise an exception when setting a construct's type to None.
Raise an exception when setting a construct's type to None.

  from django.db import models
+ 
+ from tmapi.exceptions import ModelConstraintException
  
  from construct import Construct
  
  
  class Typed (Construct, models.Model):
  
      """Indicates that a Topic Maps construct is typed. `Association`s,
      `Role`s, `Occurrence`s, and `Name`s are typed."""
  
      type = models.ForeignKey('Topic', related_name='typed_%(class)ss')
      
      class Meta:
          abstract = True
          app_label = 'tmapi'
      
      def get_type (self):
          """Returns the type of this construct.
  
          :rtype: the `Topic` that represents the type
  
          """
          return self.type
  
      def set_type (self, construct_type):
          """Sets the type of this construct. Any previous type is overridden.
  
          :param construct_type: the `Topic` that should define the
            nature of this construct
  
          """
+         if construct_type is None:
+             raise ModelConstraintException
          self.type = construct_type
          self.save()
  
Raise an exception when setting a construct's type to None.
## Code Before:
from django.db import models

from construct import Construct


class Typed (Construct, models.Model):

    """Indicates that a Topic Maps construct is typed. `Association`s,
    `Role`s, `Occurrence`s, and `Name`s are typed."""

    type = models.ForeignKey('Topic', related_name='typed_%(class)ss')
    
    class Meta:
        abstract = True
        app_label = 'tmapi'
    
    def get_type (self):
        """Returns the type of this construct.

        :rtype: the `Topic` that represents the type

        """
        return self.type

    def set_type (self, construct_type):
        """Sets the type of this construct. Any previous type is overridden.

        :param construct_type: the `Topic` that should define the
          nature of this construct

        """
        self.type = construct_type
        self.save()

## Instruction:
Raise an exception when setting a construct's type to None.
## Code After:
from django.db import models

from tmapi.exceptions import ModelConstraintException

from construct import Construct


class Typed (Construct, models.Model):

    """Indicates that a Topic Maps construct is typed. `Association`s,
    `Role`s, `Occurrence`s, and `Name`s are typed."""

    type = models.ForeignKey('Topic', related_name='typed_%(class)ss')
    
    class Meta:
        abstract = True
        app_label = 'tmapi'
    
    def get_type (self):
        """Returns the type of this construct.

        :rtype: the `Topic` that represents the type

        """
        return self.type

    def set_type (self, construct_type):
        """Sets the type of this construct. Any previous type is overridden.

        :param construct_type: the `Topic` that should define the
          nature of this construct

        """
        if construct_type is None:
            raise ModelConstraintException
        self.type = construct_type
        self.save()
