Are Sitecore events handled synchronously? - sitecore

Question

I want to hook the item:renamed event to do some processing. It may take a few minutes though. Are event handlers executed asynchronously or synchronously with normal pipeline execution? Is there a standard Sitecore way to kick this off asynchronously if I need to do that myself?
The only time this handler needs to execute is when an item is renamed in Content Editor.

Answer 1

Sitecore events are executed synchronously. There is a Sitecore Development Toolkit module on Sitecore Marketplace which contains a code for firing events asynchronously which you can easily reuse in your solution Sitecore Development Toolkit.
Here is a part of their code which fires methods asynchronously when the event is fired:
public void OnItemRenamed(object sender, EventArgs args)
{
if (args != null)
{
var item = Event.ExtractParameter(args, 0) as Item;
Assert.IsNotNull(item, "No item in parameters");
var name = Event.ExtractParameter(args, 1) as string;
Assert.IsNotNullOrEmpty(name, "No name in parameters");
DoAsync(() => OnItemRenameAsync(item, name));
}
}
private void OnItemRenameAsync(Item item, string name)
{
var itemRef = new ItemReference(item.Parent);
var itemRefText = itemRef.ToString();
// do some work here
}

Answer 2

Sitecore events are synchronous. You can kick off your long running task as a job. First create a class to handle the event:
namespace MyNamespace
{
public class MyClass
{
public void ItemRenamed (object sender, EventArgs args)
{
Run("LongRenameTask");
}
protected void Run(string methodName, EventArgs args)
{
var item = Event.ExtractParameter(args, 0) as Item;
var name = Event.ExtractParameter(args, 1) as string;
RunJob(methodName, item, name);
}
protected Handle RunJob(string methodName, Item item, string name)
{
var options = new JobOptions(
"Preparing rename job '{0}' for '{1}'".FormatWith(
methodName,
item.ID.ToString()),
"item:renamed",
"shell",
new ItemRenamedManager(item, name),
methodName)
{
WriteToLog = true,
AtomicExecution = true,
};
var job = new Job(options);
JobManager.Start(job);
return job.Handle;
}
}
}
Then create a class to do your work (this will be called on a background thread by Sitecore):
namespace MyNamespace
{
public class ItemRenamedManager
{
protected Item RenamedItem { get; set; }
protected string Name { get; set; }
public ItemRenamedManager(Item item, string name)
{
RenamedItem = item;
Name = name;
}
public void LongRenameTask()
{
// Do your long running task here.
// The property 'RenamedItem' will give you the item
}
}
}
Then patch your event handler in:
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
<sitecore>
<events>
<event name="item:renamed">
<handler type="MyNamespace.MyClass" method="ItemRenamed" />
</event>
</events>
</sitecore>
</configuration>
The above code is cribbed a bit from memory and needs some error handling, but should be pretty close, but this way, your long running task won't block the Content Editor UI.