Call QgsTaskWrapper.on_finished with exception rather than result

qgis · Dec 5, 2016 · 619381c · 619381c
1 parent fded1a1
commit 619381c
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Showing 2 changed files with 50 additions and 5 deletions.
diff --git a/python/core/__init__.py b/python/core/__init__.py
@@ -222,11 +222,14 @@ def finished(self, result):
         if not self.on_finished:
             return
 
+        if result == QgsTask.ResultFail and self.exception is None:
+            self.exception = Exception('Task cancelled')
+
         try:
             if self.returned_values:
-                self.on_finished(result, self.returned_values)
+                self.on_finished(self.exception, self.returned_values)
             else:
-                self.on_finished(result)
+                self.on_finished(self.exception)
         except Exception as ex:
             self.exception = ex
 

diff --git a/tests/src/python/test_qgstaskmanager.py b/tests/src/python/test_qgstaskmanager.py
@@ -62,16 +62,27 @@ def run_no_result(task):
     return
 
 
-def finished_no_val(result):
+def finished_no_val(e):
+    assert e is None
     finished_no_val.called = True
     return
 
 
+def run_fail(task):
+    raise Exception('fail')
+
+
+def finished_fail(e):
+    assert e
+    finished_fail.finished_exception = e
+
+
 def run_single_val_result(task):
     return 5
 
 
-def finished_single_value_result(result, value):
+def finished_single_value_result(e, value):
+    assert e is None
     finished_single_value_result.value = value
     return
 
@@ -80,7 +91,8 @@ def run_multiple_val_result(task):
     return 5, 'whoo'
 
 
-def finished_multiple_value_result(result, results):
+def finished_multiple_value_result(e, results):
+    assert e is None
     finished_multiple_value_result.value = results[0]
     finished_multiple_value_result.statement = results[1]
     return
@@ -178,6 +190,36 @@ def testTaskFromFunctionFinished(self):
         self.assertFalse(task.exception)
         self.assertTrue(finished_no_val.called)
 
+    def testTaskFromFunctionFinishedFail(self):
+        """ test that task from function which fails calls finished with exception"""
+        task = QgsTask.fromFunction('test task', run_fail, on_finished=finished_fail)
+        QgsApplication.taskManager().addTask(task)
+        while task.status() not in [QgsTask.Complete, QgsTask.Terminated]:
+            pass
+        while QgsApplication.taskManager().countActiveTasks() > 0:
+            QCoreApplication.processEvents()
+
+        # check that the finished function was called
+        self.assertTrue(task.exception)
+        self.assertTrue(finished_fail.finished_exception)
+        self.assertEqual(task.exception, finished_fail.finished_exception)
+
+    def testTaskFromFunctionCancelledWhileQueued(self):
+        """ test that task from finished is called with exception when task is terminated while queued"""
+        task = QgsTask.fromFunction('test task', run_no_result, on_finished=finished_fail)
+        task.hold()
+        QgsApplication.taskManager().addTask(task)
+        task.cancel()
+        while task.status() not in [QgsTask.Complete, QgsTask.Terminated]:
+            pass
+        while QgsApplication.taskManager().countActiveTasks() > 0:
+            QCoreApplication.processEvents()
+
+        # check that the finished function was called
+        self.assertTrue(task.exception)
+        self.assertTrue(finished_fail.finished_exception)
+        self.assertEqual(task.exception, finished_fail.finished_exception)
+
     def testTaskFromFunctionFinishedWithVal(self):
         """ test that task from function can have callback finished function and is passed result values"""
         task = QgsTask.fromFunction('test task', run_single_val_result, on_finished=finished_single_value_result)