Added service that we can call from our script

uva_crconnect_training.rst

@@ -436,7 +436,8 @@ Example code: crc/scripts/tutorial.py
 
 .. code-block:: Python
 
-    from crc.scripts.script import Script import requests
+    from crc.scripts.script import Script
+    import requests
 
 
     class TutorialScript(Script):
@@ -472,6 +473,73 @@ Example code: crc/scripts/tutorial.py
 
             return drawn_cards
 
+Best practice for creating a script involves creating a service that does the work, and calling the service from our script.
+We cover this in the next section.
+
+
+------------------
+Building a Service
+------------------
+
+Services are internal code related to a specific function. We have services that manage users and studies,
+interact with Protocol Builder and the LDAP server, send emails, and make calls to SpiffWorkflow.
+
+Services should not be called directly from outside the system. They should be called by scripts, the API, and other services.
+
+Tutorial Service
+----------------
+
+Let's build a service that replaces the do_task method in our script. We can then call the service from our script.
+
+.. code-block:: Python
+
+    import requests
+
+
+    class TutorialService(object):
+
+        @staticmethod
+        def pick_a_card(cards, decks):
+            drawn_cards = []
+
+            deck_url = f'https://deckofcardsapi.com/api/deck/new/shuffle/?deck_count={decks}'
+            deck_response = requests.get(deck_url)
+            deck_id = deck_response.json()['deck_id']
+
+            card_url = f'https://deckofcardsapi.com/api/deck/{deck_id}/draw/?count={cards}'
+            card_response = requests.get(card_url)
+
+            for card in range(cards):
+                card_value = card_response.json()['cards'][card]['value']
+                card_suit = card_response.json()['cards'][card]['suit']
+                drawn_cards.append({'suit': card_suit, 'value': card_value})
+
+            return drawn_cards
+
+We can now modify our script to call this new service.
+
+.. code-block:: Python
+
+    from crc.scripts.script import Script
+    from crc.services.tutorial_service import TutorialService
+
+    class TutorialScript(Script):
+
+        def get_description(self):
+            return """Simple script for teaching purposes"""
+
+        def do_task_validate_only(self, task, study_id, workflow_id, *args, **kwargs):
+            self.do_task(task, study_id, workflow_id, *args, **kwargs)
+
+        def do_task(self, task, study_id, workflow_id, *args, **kwargs):
+
+            cards = kwargs['cards']
+            decks = kwargs['decks']
+
+            drawn_cards = TutorialService.pick_a_card(cards=cards, decks=decks)
+            return drawn_cards
+
+
 
 -------------
 Writing Tests