Create PublicationYear on API request

Closes #3

api/views.py

@@ -78,4 +78,6 @@ def publishApiView(request, data):
             "Invalid data: {}".format(e))
     pub.save()
 
+    pub.createPubYear()
+
     return response.HttpResponse("OK")

mainsite/models.py

@@ -47,6 +47,36 @@ class Publication(models.Model):
                             max_length=128,
                             blank=True)
 
+    class NoPublicationYear(Exception):
+        def __str__(self):
+            return "No matching publication year."
+
+    @property
+    def numericPublicationYear(self):
+        startYear = self.date.year
+        if self.date.month < 8:
+            return startYear - 1
+        return startYear
+
+    def publicationYear(self):
+        ''' Fetch corresponding publication year
+        Raise `NoPublicationYear` if there is no such entry '''
+        startYear = self.numericPublicationYear
+        try:
+            return PublicationYear.objects.get(startYear=startYear)
+        except PublicationYear.DoesNotExist:
+            raise self.NoPublicationYear
+
+    def createPubYear(self):
+        ''' Creates the corresponding publication year if needed. '''
+        if (PublicationYear.objects
+                .filter(startYear=self.numericPublicationYear).count()) == 0:
+            pubYear = PublicationYear(startYear=self.numericPublicationYear,
+                                      descr='')
+            pubYear.save()
+            return True
+        return False
+
     def __str__(self):
         if self.custom_name:
             return self.custom_name