From 8fbaaf1fb708942707690bb17b878485dad91d95 Mon Sep 17 00:00:00 2001
From: Johannes Raggam <thetetet@gmail.com>
Date: Thu, 6 Jul 2023 16:58:50 +0200
Subject: [PATCH] Fix plone.memoize.view to support unhashable types in
 function arguments.

Fixes: #36
---
 news/36.bugfix         |  3 +++
 plone/memoize/view.py  |  6 ++++--
 plone/memoize/view.rst | 12 +++++++++++-
 3 files changed, 18 insertions(+), 3 deletions(-)
 create mode 100644 news/36.bugfix

diff --git a/news/36.bugfix b/news/36.bugfix
new file mode 100644
index 0000000..c8ab335
--- /dev/null
+++ b/news/36.bugfix
@@ -0,0 +1,3 @@
+Fix plone.memoize.view to support unhashable types in function arguments.
+
+Fixes: #36
diff --git a/plone/memoize/view.py b/plone/memoize/view.py
index a21e385..af70a39 100644
--- a/plone/memoize/view.py
+++ b/plone/memoize/view.py
@@ -6,6 +6,8 @@
 from zope.annotation.interfaces import IAnnotations
 from zope.globalrequest import getRequest
 
+import json
+
 
 class ViewMemo:
     key = "plone.memoize"
@@ -44,7 +46,7 @@ def memogetter(*args, **kwargs):
                 instance.__class__.__name__,
                 func.__name__,
                 args[1:],
-                frozenset(kwargs.items()),
+                frozenset(json.dumps(kwargs)),
             )
             if key not in cache:
                 cache[key] = func(*args, **kwargs)
@@ -73,7 +75,7 @@ def memogetter(*args, **kwargs):
                 instance.__class__.__name__,
                 func.__name__,
                 args[1:],
-                frozenset(kwargs.items()),
+                frozenset(json.dumps(kwargs)),
             )
             if key not in cache:
                 cache[key] = func(*args, **kwargs)
diff --git a/plone/memoize/view.rst b/plone/memoize/view.rst
index 45de49c..9397e00 100644
--- a/plone/memoize/view.rst
+++ b/plone/memoize/view.rst
@@ -81,7 +81,8 @@ Even though we've twiddled txt1, txt2 is not recalculated::
     >>> msg.txt2
     'hello world'
 
-We support memoization of multiple signatures as long as all signature values are hashable::
+We support memoization of multiple signatures.
+The signature values just need to be able to be converted into a JSON string::
 
     >>> print(msg.getMsg('Ernest'))
     Ernest: goodbye cruel world!
@@ -89,6 +90,15 @@ We support memoization of multiple signatures as long as all signature values ar
     >>> print(msg.getMsg('J.D.', **{'raise':'roofbeams'}))
     J.D.: goodbye cruel world! raise--roofbeams
 
+We also support unhashable types like lists and dicts::
+
+    >>> print(msg.getMsg('J.D.', lower=['shields', 'engines']))
+    J.D.: goodbye cruel world! lower--['shields', 'engines']
+
+    >>> print(msg.getMsg('J.D.', actions={'open': ['gates']}))
+    J.D.: goodbye cruel world! actions--{'open': ['gates']}
+
+
 We can alter data underneath, but nothing changes::
 
     >>> msg.txt1 = 'sound and fury'