implement read-only check

.gitignore

@@ -21,3 +21,4 @@
 /share/
 /src/plone.api.egg-info/
 /var/
+pip-selfcheck.json

.travis.yml

@@ -8,6 +8,7 @@ cache:
 env:
 - PLONE_VERSION=4.3
 - PLONE_VERSION=5.0
+- PLONE_VERSION=5.1
 global:
   - secure: "nTXMNU2aYbCtvKD74PndF8Xm2h6IvsxPjr6vj45AxjXmaB7Wf5oGi/4b6ObV\nexBtUQkFnc+M0ThGyUznOCPi3YxcbTzsyhQYhHUtmtw/6QRyYgo4E0GLDItU\n37Ff6wpxl3NMMJTvpi6SOVUvIJUl3+cs+4bkMkS48RSFGg2rGmo="  # Coveralls.io token
 matrix:

buildout.cfg

@@ -3,7 +3,7 @@ extends =
     https://raw.github.com/collective/buildout.plonetest/master/test-4.3.x.cfg
     plone-4.3.x.cfg
 package-name = plone.api
-package-extras = [test]
+package-extras = [develop, test]
 test-eggs = Pillow
 parts +=
     omelette

docs/env.rst

@@ -109,12 +109,17 @@ Read-Only mode
 
 To know if your Zope / Plone instance is running on a read-only ZODB connection use :meth:`api.env.read_only_mode`.
 
+**Use-Case:**
+If you run a ZRS or RelStorage cluster with active replication where all replicas are read-only be default.
+You could check if your instance is connected to a read only ZODB or a writeable ZODB.
+Therefore you could adjust the UI to prevent create, delete or update pages are shown.
+
 .. code-block:: python
 
     from plone import api
 
-    in_test_mode = api.env.read_only_mode()
-    if in_test_mode:
+    is_read_only = api.env.read_only_mode()
+    if is_read_only:
         pass  # do something
 
 

plone-5.1.x.cfg

@@ -0,0 +1,6 @@
+[buildout]
+test-eggs +=
+    plone.app.contenttypes
+
+[versions]
+plone.api =

src/plone/api/env.py

@@ -13,6 +13,7 @@
 from plone.api.validation import required_parameters
 from zope.globalrequest import getRequest
 
+import Globals
 import traceback
 
 
@@ -206,9 +207,12 @@ def read_only_mode():
 
     :Example: :ref:`env_read_only_mode_example`
     """
-    conn = Globals.DB.open()
-    isReadOnly = conn.isReadOnly()
-    conn.close()
+    isReadOnly = True
+    try:
+        conn = Globals.DB.open()
+        isReadOnly = conn.isReadOnly()
+    finally:
+        conn.close()
     return isReadOnly
 
 

src/plone/api/tests/test_env.py

@@ -402,6 +402,12 @@ def test_test_mode(self):
         from plone.api.env import test_mode
         self.assertEqual(test_mode(), True)
 
+    def test_read_only_mode(self):
+        """Test that read_only_mode() returns False
+        as we have a write enabled ZODB."""
+        from plone.api.env import read_only_mode
+        self.assertFalse(read_only_mode())
+
     def test_plone_version(self):
         """Tests that plone_version() returns Plone version."""
         from plone.api.env import plone_version