Files
Umbraco-CMS/src/Umbraco.Core/Events/EventExtensions.cs

82 lines
2.9 KiB
C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
namespace Umbraco.Core.Events
{
/// <summary>
/// Extension methods for cancellable event operations
/// </summary>
public static class EventExtensions
{
/// <summary>
/// Raises the event and returns a boolean value indicating if the event was cancelled
/// </summary>
/// <typeparam name="TSender"></typeparam>
/// <typeparam name="TArgs"></typeparam>
/// <param name="eventHandler"></param>
/// <param name="args"></param>
/// <param name="sender"></param>
/// <returns></returns>
public static bool IsRaisedEventCancelled<TSender, TArgs>(
this TypedEventHandler<TSender, TArgs> eventHandler,
TArgs args,
TSender sender)
where TArgs : CancellableEventArgs
{
if (eventHandler != null)
eventHandler(sender, args);
return args.Cancel;
}
/// <summary>
/// Raises the event
/// </summary>
/// <typeparam name="TSender"></typeparam>
/// <typeparam name="TArgs"></typeparam>
/// <param name="eventHandler"></param>
/// <param name="args"></param>
/// <param name="sender"></param>
public static void RaiseEvent<TSender, TArgs>(
this TypedEventHandler<TSender, TArgs> eventHandler,
TArgs args,
TSender sender)
where TArgs : EventArgs
{
if (eventHandler != null)
eventHandler(sender, args);
}
// moves the last handler that was added to an instance event, to first position
public static void PromoteLastHandler(object sender, string eventName)
{
var fieldInfo = sender.GetType().GetField(eventName, BindingFlags.Instance | BindingFlags.NonPublic);
if (fieldInfo == null) throw new InvalidOperationException("No event named " + eventName + ".");
PromoteLastHandler(sender, fieldInfo);
}
// moves the last handler that was added to a static event, to first position
public static void PromoteLastHandler<TSender>(string eventName)
{
var fieldInfo = typeof(TSender).GetField(eventName, BindingFlags.Static | BindingFlags.NonPublic);
if (fieldInfo == null) throw new InvalidOperationException("No event named " + eventName + ".");
PromoteLastHandler(null, fieldInfo);
}
private static void PromoteLastHandler(object sender, FieldInfo fieldInfo)
{
var d = fieldInfo.GetValue(sender) as Delegate;
if (d == null) return;
var l = d.GetInvocationList();
var x = l[l.Length - 1];
for (var i = l.Length - 1; i > 0; i--)
l[i] = l[i - 1];
l[0] = x;
fieldInfo.SetValue(sender, Delegate.Combine(l));
}
}
}