private static void InterpretEventDescriptor(BrowserEventDescriptor eventDescriptor)
{
// The incoming field value can be either a bool or a string, but since the .NET property
// type is 'object', it will deserialize initially as a JsonElement
var fieldInfo = eventDescriptor.EventFieldInfo;
if (fieldInfo != null)
{
if (fieldInfo.FieldValue is JsonElement attributeValueJsonElement)
{
switch (attributeValueJsonElement.ValueKind)
{
case JsonValueKind.True:
case JsonValueKind.False:
fieldInfo.FieldValue = attributeValueJsonElement.GetBoolean();
break;
default:
fieldInfo.FieldValue = attributeValueJsonElement.GetString();
break;
}
}
else
{
// Unanticipated value type. Ensure we don't do anything with it.
eventDescriptor.EventFieldInfo = null;
}
}
}
public static Task DispatchEvent(
BrowserEventDescriptor eventDescriptor, string eventArgsJson)
{
var eventArgs = ParseEventArgsJson(eventDescriptor.EventArgsType, eventArgsJson);
var renderer = RendererRegistry.Current.Find(eventDescriptor.BrowserRendererId);
return(renderer.DispatchEventAsync(eventDescriptor.EventHandlerId, eventArgs));
}
public static void DispatchEvent(
BrowserEventDescriptor eventDescriptor, string eventArgsJson)
{
var eventArgs = ParseEventArgsJson(eventDescriptor.EventArgsType, eventArgsJson);
var browserRenderer = BrowserRendererRegistry.Find(eventDescriptor.BrowserRendererId);
browserRenderer.DispatchBrowserEvent(
eventDescriptor.ComponentId,
eventDescriptor.EventHandlerId,
eventArgs);
}
public static Task DispatchEvent(
BrowserEventDescriptor eventDescriptor, string eventArgsJson)
{
// Be sure we only run one event handler at once. Although they couldn't run
// simultaneously anyway (there's only one thread), they could run nested on
// the stack if somehow one event handler triggers another event synchronously.
// We need event handlers not to overlap because (a) that's consistent with
// server-side Blazor which uses a sync context, and (b) the rendering logic
// relies completely on the idea that within a given scope it's only building
// or processing one batch at a time.
//
// The only currently known case where this makes a difference is in the E2E
// tests in ReorderingFocusComponent, where we hit what seems like a Chrome bug
// where mutating the DOM cause an element's "change" to fire while its "input"
// handler is still running (i.e., nested on the stack) -- this doesn't happen
// in Firefox. Possibly a future version of Chrome may fix this, but even then,
// it's conceivable that DOM mutation events could trigger this too.
if (isDispatchingEvent)
{
var info = new IncomingEventInfo(eventDescriptor, eventArgsJson);
deferredIncomingEvents.Enqueue(info);
return(info.TaskCompletionSource.Task);
}
else
{
isDispatchingEvent = true;
try
{
var eventArgs = ParseEventArgsJson(eventDescriptor.EventArgsType, eventArgsJson);
var renderer = RendererRegistry.Current.Find(eventDescriptor.BrowserRendererId);
return(renderer.DispatchEventAsync(eventDescriptor.EventHandlerId, eventArgs));
}
finally
{
isDispatchingEvent = false;
if (deferredIncomingEvents.Count > 0)
{
ProcessNextDeferredEvent();
}
}
}
}
public IncomingEventInfo(BrowserEventDescriptor eventDescriptor, string eventArgsJson)
{
EventDescriptor = eventDescriptor;
EventArgsJson = eventArgsJson;
TaskCompletionSource = new TaskCompletionSource <object>();
}
