Using an idea of promotion. Request -> Pending -> Completed

restscrape/models.py

@@ -82,12 +82,30 @@ class PageRequestTask(models.Model):
         return res
 
 
+class ScrapeRequest(models.Model):
+    # internal
+    submit_time = models.DateTimeField(editable=False)
+    # parameters
+    blocking = models.BooleanField()
+    url = models.URLField()
+    use_adblock = models.BooleanField()
+    wait_for = models.IntegerField()
+    xpath_labels = extended_fields.HStoreField()
+
+    def submit(self):
+        self.save()
+        pending = PendingScrapingResponse(request=self)
+        pending.save()
+        return pending
+
+
 class ScrapingResponse(models.Model):
     id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
 
 
 class PendingScrapingResponse(ScrapingResponse):
     task = models.ForeignKey(PageRequestTask, on_delete=models.CASCADE)
+    request = models.ForeignKey(ScrapeRequest, on_delete=models.CASCADE)
 
     def mark_complete(self, xpath_labels):
         completion_time = datetime.datetime.now(pytz.UTC)
@@ -95,6 +113,7 @@ class PendingScrapingResponse(ScrapingResponse):
             xpath_labels=xpath_labels, completion_time=completion_time, id=self.id
         )
         completed_response.save()
+        self.request.delete()
         self.delete()
         return completed_response
 
@@ -102,14 +121,3 @@ class PendingScrapingResponse(ScrapingResponse):
 class CompletedScrapingResponse(ScrapingResponse):
     xpath_labels = extended_fields.JSONField()
     completion_time = models.DateTimeField()
-
-
-class ScrapeRequest(models.Model):
-    # internal
-    submit_time = models.DateTimeField(auto_now=True, editable=False)
-    # parameters
-    blocking = models.BooleanField()
-    url = models.URLField()
-    use_adblock = models.BooleanField()
-    wait_for = models.IntegerField()
-    xpath_labels = extended_fields.HStoreField()