public void DisposesEventHandlersWhenAttributeValueChanged()
{
// Arrange
var renderer = new TestRenderer();
var eventCount = 0;
UIEventHandler origEventHandler = args => { eventCount++; };
var component = new EventComponent {
OnTest = origEventHandler
};
var componentId = renderer.AssignComponentId(component);
component.TriggerRender();
var origEventHandlerId = renderer.Batches.Single()
.ReferenceFrames
.Where(f => f.FrameType == RenderTreeFrameType.Attribute)
.Single(f => f.AttributeEventHandlerId != 0)
.AttributeEventHandlerId;
// Act/Assert 1: Event handler fires when we trigger it
Assert.Equal(0, eventCount);
renderer.DispatchEvent(componentId, origEventHandlerId, args: null);
Assert.Equal(1, eventCount);
// Now change the attribute value
var newEventCount = 0;
component.OnTest = args => { newEventCount++; };
component.TriggerRender();
// Act/Assert 2: Can no longer fire the original event, but can fire the new event
Assert.Throws <ArgumentException>(() =>
{
renderer.DispatchEvent(componentId, origEventHandlerId, args: null);
});
Assert.Equal(1, eventCount);
Assert.Equal(0, newEventCount);
renderer.DispatchEvent(componentId, origEventHandlerId + 1, args: null);
Assert.Equal(1, newEventCount);
}
public void AllRendersTriggeredSynchronouslyDuringEventHandlerAreHandledAsSingleBatch()
{
// Arrange: A root component with a child whose event handler explicitly queues
// a re-render of both the root component and the child
var renderer = new TestRenderer();
var eventCount = 0;
TestComponent rootComponent = null;
EventComponent childComponent = null;
rootComponent = new TestComponent(builder =>
{
builder.AddContent(0, "Child event count: " + eventCount);
builder.OpenComponent <EventComponent>(1);
builder.AddAttribute(2, nameof(EventComponent.OnTest), args =>
{
eventCount++;
rootComponent.TriggerRender();
childComponent.TriggerRender();
});
builder.CloseComponent();
});
var rootComponentId = renderer.AssignComponentId(rootComponent);
rootComponent.TriggerRender();
var origBatchReferenceFrames = renderer.Batches.Single().ReferenceFrames;
var childComponentFrame = origBatchReferenceFrames
.Single(f => f.Component is EventComponent);
var childComponentId = childComponentFrame.ComponentId;
childComponent = (EventComponent)childComponentFrame.Component;
var origEventHandlerId = origBatchReferenceFrames
.Where(f => f.FrameType == RenderTreeFrameType.Attribute)
.Last(f => f.AttributeEventHandlerId != 0)
.AttributeEventHandlerId;
Assert.Single(renderer.Batches);
// Act
renderer.DispatchEvent(childComponentId, origEventHandlerId, args: null);
// Assert
Assert.Equal(2, renderer.Batches.Count);
var batch = renderer.Batches.Last();
Assert.Collection(batch.DiffsInOrder,
diff =>
{
// First we triggered the root component to re-render
Assert.Equal(rootComponentId, diff.ComponentId);
Assert.Collection(diff.Edits, edit =>
{
Assert.Equal(RenderTreeEditType.UpdateText, edit.Type);
AssertFrame.Text(
batch.ReferenceFrames[edit.ReferenceFrameIndex],
"Child event count: 1");
});
},
diff =>
{
// Then the root re-render will have triggered an update to the child
Assert.Equal(childComponentId, diff.ComponentId);
Assert.Collection(diff.Edits, edit =>
{
Assert.Equal(RenderTreeEditType.UpdateText, edit.Type);
AssertFrame.Text(
batch.ReferenceFrames[edit.ReferenceFrameIndex],
"Render count: 2");
});
},
diff =>
{
// Finally we explicitly requested a re-render of the child
Assert.Equal(childComponentId, diff.ComponentId);
Assert.Collection(diff.Edits, edit =>
{
Assert.Equal(RenderTreeEditType.UpdateText, edit.Type);
AssertFrame.Text(
batch.ReferenceFrames[edit.ReferenceFrameIndex],
"Render count: 3");
});
});
}
