Source code for derrida.footnotes.models

from django.db import models
from django.contrib.contenttypes.fields import GenericForeignKey
from django.contrib.contenttypes.models import ContentType

from derrida.common.models import Named, Notable


class SourceType(Named, Notable):
    '''Type of source document.'''

    def item_count(self):
        '''number of associated bibliographic items'''
        return self.bibliography_set.count()
    item_count.short_description = '# items'


class Bibliography(Notable):  # would citation be a better singular?
    bibliographic_note = models.TextField(
        help_text='Full bibliographic citation')
    source_type = models.ForeignKey(SourceType)

    class Meta:
        verbose_name_plural = 'Bibliographies'

    def __str__(self):
        return self.bibliographic_note

    def footnote_count(self):
        '''number of footnotes this item is referenced in'''
        return self.footnote_set.count()
    footnote_count.short_description = '# footnotes'


class Footnote(Notable):
    '''Footnote that can be associated with any other model via
    generic relationship.  Used to provide supporting documentation
    for or against information in the system.
    '''
    bibliography = models.ForeignKey(Bibliography)
    location = models.TextField(blank=True,
        help_text='Page number for a book, URL for part of a website,' +
        ' or other location inside of a larger work.')
    snippet_text = models.TextField(blank=True)
    content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE,
        # restrict choices to "content" models (exclude django/admin models)
        # and models that are available in django admin
        # (otherwise, lookup is not possible)
        limit_choices_to=models.Q(app_label='places') |
             models.Q(app_label='people',
                      model__in=['person', 'relationshiptype']) |
             models.Q(app_label='books',
                      model__in=['work', 'instance', 'derridawork',
                                 'referencetype', 'reference', 'itemtype',
                                 'journal', 'subject', 'language',
                                 'publisher', 'owninginstitution']))
    object_id = models.PositiveIntegerField()
    content_object = GenericForeignKey('content_type', 'object_id')
    is_agree = models.BooleanField(help_text='True if the evidence ' +
        'supports the information in the system, False if it contradicts.')

    def __str__(self):
        return 'Footnote on %s' % (self.content_object)

    # NOTE: for convenient access from other models, add a
    # reverse generic relation
    #
    # from django.contrib.contenttypes.fields import GenericRelation
    # from derrida.footnoter.models import Footnote
    #
    # footnotes = GenericRelation(Footnote)