__copyright__ = "Copyright © Stichting SciPost (SciPost Foundation)"
__license__ = "AGPL v3"
from django.core.exceptions import ValidationError
from django.db import models
from django.db.models import Avg, F
from django.utils import timezone
from ..constants import ISSUES_AND_VOLUMES
from ..validators import doi_volume_validator
[docs]class Volume(models.Model):
"""
A Volume belongs to a specific Journal, and is a container for
either (multiple) Issue(s) or Publication(s).
"""
in_journal = models.ForeignKey(
'journals.Journal', limit_choices_to={'structure': ISSUES_AND_VOLUMES},
on_delete=models.CASCADE)
number = models.PositiveSmallIntegerField()
start_date = models.DateField(default=timezone.now)
until_date = models.DateField(default=timezone.now)
doi_label = models.CharField(max_length=200, unique=True, db_index=True,
validators=[doi_volume_validator])
class Meta:
default_related_name = 'volumes'
ordering = ('-until_date',)
unique_together = ('number', 'in_journal')
def __str__(self):
return str(self.in_journal) + ' Vol. ' + str(self.number)
[docs] def clean(self):
"""Check if the Volume is assigned to a valid Journal."""
if not self.in_journal.has_volumes:
raise ValidationError({
'in_journal': ValidationError('This journal does not allow for the use of Volumes',
code='invalid'),
})
@property
def doi_string(self):
return '10.21468/' + self.doi_label
[docs] def is_current(self):
today = timezone.now().date()
return self.start_date <= today and self.until_date >= today
[docs] def nr_publications(self, tier=None):
from journals.models import Publication
publications = Publication.objects.filter(in_issue__in_volume=self)
if tier:
publications = publications.filter(
accepted_submission__eicrecommendations__recommendation=tier)
return publications.count()
[docs] def avg_processing_duration(self):
from journals.models import Publication
duration = Publication.objects.filter(
in_issue__in_volume=self).aggregate(
avg=Avg(F('publication_date') - F('submission_date')))['avg']
if duration:
return duration.total_seconds() / 86400
return 0
[docs] def citation_rate(self, tier=None):
"""Returns the citation rate in units of nr citations per article per year."""
from journals.models import Publication
publications = Publication.objects.filter(in_issue__in_volume=self)
if tier:
publications = publications.filter(
accepted_submission__eicrecommendations__recommendation=tier)
ncites = 0
deltat = 1 # to avoid division by zero
for pub in publications:
if pub.citedby and pub.latest_citedby_update:
ncites += len(pub.citedby)
deltat += (pub.latest_citedby_update.date() - pub.publication_date).days
return (ncites * 365.25 / deltat)