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mayan-edms/mayan/apps/metadata/models.py

91 lines
3.8 KiB
Python

from __future__ import unicode_literals
from django.core.exceptions import ValidationError
from django.db import models
from django.utils.encoding import python_2_unicode_compatible
from django.utils.translation import ugettext_lazy as _
from documents.models import Document, DocumentType
from .managers import MetadataTypeManager
from .settings import AVAILABLE_VALIDATORS
@python_2_unicode_compatible
class MetadataType(models.Model):
"""
Define a type of metadata
"""
name = models.CharField(unique=True, max_length=48, verbose_name=_('Name'), help_text=_('Do not use python reserved words, or spaces.'))
# TODO: normalize 'title' to 'label'
title = models.CharField(max_length=48, verbose_name=_('Title'))
default = models.CharField(max_length=128, blank=True, null=True,
verbose_name=_('Default'),
help_text=_('Enter a string to be evaluated.'))
# TODO: Add enable_lookup boolean to allow users to switch the lookup on and
# off without losing the lookup expression
lookup = models.TextField(blank=True, null=True,
verbose_name=_('Lookup'),
help_text=_('Enter a string to be evaluated that returns an iterable.'))
validation = models.CharField(blank=True, choices=zip(AVAILABLE_VALIDATORS, AVAILABLE_VALIDATORS), max_length=64, verbose_name=_('Validation function name'))
# TODO: Find a different way to let users know what models and functions are
# available now that we removed these from the help_text
objects = MetadataTypeManager()
def __str__(self):
return self.title
def natural_key(self):
return (self.name,)
class Meta:
ordering = ('title',)
verbose_name = _('Metadata type')
verbose_name_plural = _('Metadata types')
@python_2_unicode_compatible
class DocumentMetadata(models.Model):
"""
Link a document to a specific instance of a metadata type with it's
current value
"""
document = models.ForeignKey(Document, related_name='metadata', verbose_name=_('Document'))
metadata_type = models.ForeignKey(MetadataType, verbose_name=_('Type'))
value = models.CharField(max_length=255, blank=True, null=True, verbose_name=_('Value'), db_index=True)
def __str__(self):
return unicode(self.metadata_type)
def save(self, *args, **kwargs):
if self.metadata_type.pk not in self.document.document_type.metadata.values_list('metadata_type', flat=True):
raise ValidationError(_('Metadata type is not valid for this document type.'))
return super(DocumentMetadata, self).save(*args, **kwargs)
def delete(self, enforce_required=True, *args, **kwargs):
if enforce_required and self.metadata_type.pk in self.document.document_type.metadata.filter(required=True).values_list('metadata_type', flat=True):
raise ValidationError(_('Metadata type is required for this document type.'))
return super(DocumentMetadata, self).delete(*args, **kwargs)
class Meta:
unique_together = ('document', 'metadata_type')
verbose_name = _('Document metadata')
verbose_name_plural = _('Document metadata')
@python_2_unicode_compatible
class DocumentTypeMetadataType(models.Model):
document_type = models.ForeignKey(DocumentType, related_name='metadata', verbose_name=_('Document type'))
metadata_type = models.ForeignKey(MetadataType, verbose_name=_('Metadata type'))
required = models.BooleanField(default=False, verbose_name=_('Required'))
def __str__(self):
return unicode(self.metadata_type)
class Meta:
unique_together = ('document_type', 'metadata_type')
verbose_name = _('Document type metadata type options')
verbose_name_plural = _('Document type metadata types options')