Making use of the "user" events

Question

I'm using Sitecore 9.1.1, and in the sitecore.config there are a series of user events (user:created, user:created:remote, user:deleted, user:deleted:remote, user:updated, user:updated:remote, etc). Each entry has a comment that suggests the type of input it takes...for example, for user:created, it shows a comment of user:created(System.Web.Security.MembershipUser user). I created a method like the following:

namespace Foundation.Core.Events {
  public class UserEvents {
    private readonly ILogRepository _logRepository;

    public UserEvents(ILogRepository logRepository) {
        _logRepository = logRepository;
    }

    public void OnUserCreated(System.Web.Security.MembershipUser user) {
        _logRepository.Info("OnUserCreated fired");
    }
  }
}

And did a patch as follows:

  <sitecore>
    <events>
        <event name="user:created">
            <handler type="Foundation.Core.Events.UserEvents, Foundation.Core" method="OnUserCreated" resolve="true" />
        </event>
    </events>
  </sitecore>

When I built out the code, I got back the following error:

Could not instantiate event handler. Type: Foundation.Core.Events.UserEvents. Method: OnUserCreated (method: Sitecore.Events.Event.BuildConfigSubscribersFromConfiguration()).

I tried paring the method down to remove the dependency injection and constructor, in case that was causing an issue, but I get the same error regardless. Since there are no "live" events in here, there's no direct pattern to follow, but I went with the definition from Sitecore's config as a guidance.

Has anyone ever used these events, and if so how did you tie into the system?

Answer 1

Any event handler has to follow a few conventions:

The class must have a method that accepts two parameters and return void:

1. object - represents the object that holds a collection of the various event listeners
2. EventArgs - holds the parameters being passed to the event handler

For your case, if you added the following event handlers for the user:created or user:created:remote events in a Sitecore patch file

 <sitecore>
    <events>
        <event name="user:created">
            <handler type="Foundation.Core.Events.UserEvents, Foundation.Core" method="OnUserCreated" resolve="true" />
        </event>
        <event name="user:created:remote">
            <handler type="Foundation.Core.Events.UserEvents, Foundation.Core" method="OnUserCreatedRemote" resolve=“true” />
        </event>
    </events>
  </sitecore>

their implementation is supposed to be like

namespace Foundation.Core.Events 
{
  public class UserEvents 
  {
    ...
    public void OnUserCreated(Object o, EventArgs args) 
    {
       var scEventArgs = (SitecoreEventArgs)args;
       var user = (MembershipUser)scEventArgs.Parameters[0];
        _logRepository.Info("OnUserCreated: " + user.UserName);
    }

    public void OnUserCreatedRemote(Object o, EventArgs args) 
    {
       var scEventArgs = (SitecoreEventArgs)args;
       var remoteEventArgs = (UserCreatedRemoteEventArgs)scEventArgs.Parameters[0];
       _logRepository.Info("OnUserCreatedRemote: " + remoteEventArgs.UserName);
    }
  }
}