From fea05bb0dba069c82b9dbe2a71b31f88cf54a712 Mon Sep 17 00:00:00 2001
From: Christian Mollekopf <chrigi_1@fastmail.fm>
Date: Tue, 28 Feb 2017 19:51:52 +0100
Subject: Avoid "Unable to assign...." errors

i.e. "Unable to assign [undefined] to Sink::ApplicationDomain::Folder::Ptr"
Because qml does not know how to assign a default-constructed value we
have to use conditional bindings. The !! operator checks for
availability of the property which then triggers the binding.

I assume an alternative viable approach would be to expose all
controller properties as QVariants only, in which case an assignment
from null would work (it doesn't for Folder::Ptr).
---
 components/mail/contents/ui/Mail.qml              | 12 ++++++++++--
 components/package/contents/ui/FolderListView.qml |  8 ++++++--
 components/package/contents/ui/MailListView.qml   |  2 +-
 3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/components/mail/contents/ui/Mail.qml b/components/mail/contents/ui/Mail.qml
index b88e846d..c400d8f3 100644
--- a/components/mail/contents/ui/Mail.qml
+++ b/components/mail/contents/ui/Mail.qml
@@ -84,12 +84,20 @@ Controls2.ApplicationWindow {
     //Controller
     KubeFramework.MailController {
         id: mailController
-        threadLeader: mailListView.currentMail
+        Binding on threadLeader {
+            //!! checks for the availability of the type
+            when: !!mailListView.currentMail
+            value: mailListView.currentMail
+        }
     }
 
     KubeFramework.FolderController {
         id: folderController
-        folder: folderListView.currentFolder
+        Binding on folder {
+            //!! checks for the availability of the type
+            when: !!folderListView.currentFolder
+            value: folderListView.currentFolder
+        }
     }
 
     //BEGIN Shortcuts
diff --git a/components/package/contents/ui/FolderListView.qml b/components/package/contents/ui/FolderListView.qml
index 9ac73fb4..a4d25e02 100644
--- a/components/package/contents/ui/FolderListView.qml
+++ b/components/package/contents/ui/FolderListView.qml
@@ -28,14 +28,18 @@ import org.kube.framework.domain 1.0 as KubeFramework
 Rectangle {
     id: root
 
-    property variant currentFolder
+    property variant currentFolder: null
     property variant accountId
 
     color: Kirigami.Theme.textColor
 
     KubeFramework.FolderController {
         id: folderController
-        folder: root.currentFolder
+        Binding on folder {
+            //!! checks for the availability of the type
+            when: !!root.currentFolder
+            value: root.currentFolder
+        }
     }
 
     Menu {
diff --git a/components/package/contents/ui/MailListView.qml b/components/package/contents/ui/MailListView.qml
index 1467979a..35fd4ec9 100644
--- a/components/package/contents/ui/MailListView.qml
+++ b/components/package/contents/ui/MailListView.qml
@@ -28,7 +28,7 @@ import org.kube.framework.domain 1.0 as KubeFramework
 Item {
     id: root
     property variant parentFolder
-    property variant currentMail
+    property variant currentMail: null
     property bool isDraft : false
     property int currentIndex
 
-- 
cgit v1.2.3