Avoid TypeError when remove used style (#829)

* Avoid ``TypeError`` when remove used style

* Add upgrade step

* Fix changelog

CHANGES.rst

@@ -6,6 +6,9 @@ There's a frood who really knows where his towel is.
 2.0b2 (unreleased)
 ^^^^^^^^^^^^^^^^^^
 
+- Avoid ``TypeError`` when a style used on a tile was removed (fixes `#827 <https://github.com/collective/collective.cover/issues/827>`_).
+  [rodfersou]
+
 - Avoid ``KeyError`` when tile schema has changed (refs. `brasil.gov.portal#524 <https://github.com/plonegovbr/brasil.gov.portal/issues/524>`_).
   [hvelarde]
 

src/collective/cover/profiles/default/metadata.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0"?>
 <metadata>
-  <version>21</version>
+  <version>22</version>
   <dependencies>
     <dependency>profile-collective.js.galleria:default</dependency>
     <dependency>profile-collective.js.jqueryui:default</dependency>

src/collective/cover/static/js/layout_edit.js

@@ -50,6 +50,9 @@
         if (key === 'tile-default') {
           continue;
         }
+        if (this.options[key] == null) {
+          continue;
+        }
         this.options[key].selected = true;
       }
       this.update();

src/collective/cover/tests/test_upgrades.py

@@ -263,3 +263,14 @@ def test_registrations(self):
         version = self.setup.getLastVersionForProfile(self.profile_id)[0]
         self.assertGreaterEqual(int(version), int(self.to_version))
         self.assertEqual(self._how_many_upgrades_to_do(), 1)
+
+
+class Upgrade21to22TestCase(UpgradeTestCaseBase):
+
+    def setUp(self):
+        UpgradeTestCaseBase.setUp(self, u'21', u'22')
+
+    def test_registrations(self):
+        version = self.setup.getLastVersionForProfile(self.profile_id)[0]
+        self.assertGreaterEqual(int(version), int(self.to_version))
+        self.assertEqual(self._how_many_upgrades_to_do(), 1)

src/collective/cover/upgrades/configure.zcml

@@ -7,4 +7,5 @@
   <include package=".v19" />
   <include package=".v20" />
   <include package=".v21" />
+  <include package=".v22" />
 </configure>

src/collective/cover/upgrades/v22/__init__.py

@@ -0,0 +1 @@
+# -*- coding: utf-8 -*-

src/collective/cover/upgrades/v22/configure.zcml

@@ -0,0 +1,19 @@
+<configure
+    xmlns="http://namespaces.zope.org/zope"
+    xmlns:genericsetup="http://namespaces.zope.org/genericsetup"
+    xmlns:i18n="http://namespaces.zope.org/i18n"
+    i18n_domain="collective.cover">
+
+  <genericsetup:upgradeSteps
+      source="21"
+      destination="22"
+      profile="collective.cover:default">
+
+    <genericsetup:upgradeStep
+        title="Cook JS resources"
+        handler="..cook_javascript_resources"
+        />
+
+  </genericsetup:upgradeSteps>
+
+</configure>