Files
mayan-edms/mayan/apps/linking/models.py

81 lines
3.6 KiB
Python

from __future__ import unicode_literals
from django.db import models
from django.db.models import Q
from django.utils.encoding import python_2_unicode_compatible
from django.utils.translation import ugettext_lazy as _
from documents.models import Document, DocumentType
from .literals import (
INCLUSION_AND, INCLUSION_CHOICES, INCLUSION_OR, OPERATOR_CHOICES
)
from .managers import SmartLinkManager
@python_2_unicode_compatible
class SmartLink(models.Model):
title = models.CharField(max_length=96, verbose_name=_('Title'))
dynamic_title = models.CharField(blank=True, max_length=96, verbose_name=_('Dynamic title'), help_text=_('This expression will be evaluated against the current selected document.'))
enabled = models.BooleanField(default=True, verbose_name=_('Enabled'))
document_types = models.ManyToManyField(DocumentType, verbose_name=_('Document types'))
objects = SmartLinkManager()
def __str__(self):
return self.title
def get_dynamic_title(self, document):
if self.dynamic_title:
try:
return eval(self.dynamic_title, {'document': document})
except Exception as exception:
return Exception(_('Error generating dynamic title; %s' % unicode(exception)))
else:
return self.title
def get_linked_document_for(self, document):
if document.document_type.pk not in self.document_types.values_list('pk', flat=True):
raise Exception(_('This smart link is not allowed for the selected document\'s type.'))
smart_link_query = Q()
for condition in self.conditions.filter(enabled=True):
condition_query = Q(**{
'%s__%s' % (condition.foreign_document_data, condition.operator): eval(condition.expression, {'document': document})
})
if condition.negated:
condition_query = ~condition_query
if condition.inclusion == INCLUSION_AND:
smart_link_query &= condition_query
elif condition.inclusion == INCLUSION_OR:
smart_link_query |= condition_query
if smart_link_query:
return Document.objects.filter(smart_link_query)
else:
return Document.objects.none()
class Meta:
verbose_name = _('Smart link')
verbose_name_plural = _('Smart links')
@python_2_unicode_compatible
class SmartLinkCondition(models.Model):
smart_link = models.ForeignKey(SmartLink, related_name='conditions', verbose_name=_('Smart link'))
inclusion = models.CharField(default=INCLUSION_AND, max_length=16, choices=INCLUSION_CHOICES, help_text=_('The inclusion is ignored for the first item.'))
foreign_document_data = models.CharField(max_length=128, verbose_name=_('Foreign document attribute'), help_text=_('This represents the metadata of all other documents.'))
operator = models.CharField(max_length=16, choices=OPERATOR_CHOICES)
expression = models.TextField(verbose_name=_('Expression'), help_text=_('This expression will be evaluated against the current document.'))
negated = models.BooleanField(default=False, verbose_name=_('Negated'), help_text=_('Inverts the logic of the operator.'))
enabled = models.BooleanField(default=True, verbose_name=_('Enabled'))
def __str__(self):
return '%s foreign %s %s %s %s' % (self.get_inclusion_display(), self.foreign_document_data, _('not') if self.negated else '', self.get_operator_display(), self.expression)
class Meta:
verbose_name = _('Link condition')
verbose_name_plural = _('Link conditions')