From 1d3cef4ab8f35a6938e45ab905c81c77d8a882c3 Mon Sep 17 00:00:00 2001
From: Paul Hewlett <phewlett76@gmail.com>
Date: Wed, 12 May 2021 15:16:50 +0100
Subject: [PATCH] Cache subclass instances

Problem:
On instantiation of archivist extra subclassesa are also instantiated
even if not needed.

Solution:
Hide instantiation of subclasses behind a property.

Signed-off-by: Paul Hewlett <phewlett76@gmail.com>
---
 archivist/archivist.py     | 36 ++++++++++++++++++++++++++++++++----
 unittests/testarchivist.py | 24 ++++++++++++++++++++++++
 2 files changed, 56 insertions(+), 4 deletions(-)

diff --git a/archivist/archivist.py b/archivist/archivist.py
index 7bf7f686..86804c65 100644
--- a/archivist/archivist.py
+++ b/archivist/archivist.py
@@ -67,10 +67,38 @@ def __init__(self, url, *, auth=None, cert=None, verify=True):
 
         self._cert = cert
 
-        self.assets = _AssetsClient(self)
-        self.events = _EventsClient(self)
-        self.locations = _LocationsClient(self)
-        self.attachments = _AttachmentsClient(self)
+        self._assets = None
+        self._events = None
+        self._locations = None
+        self._attachments = None
+
+    @property
+    def assets(self):
+        """docstring"""
+        if self._assets is None:
+            self._assets = _AssetsClient(self)
+        return self._assets
+
+    @property
+    def events(self):
+        """docstring"""
+        if self._events is None:
+            self._events = _EventsClient(self)
+        return self._events
+
+    @property
+    def locations(self):
+        """docstring"""
+        if self._locations is None:
+            self._locations = _LocationsClient(self)
+        return self._locations
+
+    @property
+    def attachments(self):
+        """docstring"""
+        if self._attachments is None:
+            self._attachments = _AttachmentsClient(self)
+        return self._attachments
 
     @property
     def headers(self):
diff --git a/unittests/testarchivist.py b/unittests/testarchivist.py
index 159cfc06..f8f2ef08 100644
--- a/unittests/testarchivist.py
+++ b/unittests/testarchivist.py
@@ -33,6 +33,30 @@ def test_archivist(self):
         Test default archivist creation
         """
         arch = Archivist("url", auth="authauthauth")
+        self.assertIsNotNone(
+            arch.assets,
+            msg="Incorrect assets",
+        )
+        self.assertIsNotNone(
+            arch.events,
+            msg="Incorrect events",
+        )
+        self.assertIsNotNone(
+            arch.locations,
+            msg="Incorrect locations",
+        )
+        self.assertIsNotNone(
+            arch.locations,
+            msg="Incorrect locations",
+        )
+        self.assertIsNotNone(
+            arch.attachments,
+            msg="Incorrect attachments",
+        )
+        self.assertIsNotNone(
+            arch.attachments,
+            msg="Incorrect attachments",
+        )
         self.assertEqual(
             arch.url,
             "url",