How to display a popup when saving a Sitecore item?

Question

When saving a Sitecore item I am trying to display a popup to interact with the user. Depending on data that they have changed I may display a series of 1 or 2 popups asking them if they want to continue. I have figured out how to tap in to the OnItemSaving pipeline. That is simple. What I can't figure out is how to display a popup and react to the input from the user. Right now I am thinking that I should be using the Sitecore.Context.ClientPage.ClientResponse object somehow. Here is some code that shows what I am trying to do:

public class MyCustomEventProcessor
{
    public void OnItemSaving(object sender, EventArgs args)
    {
      if([field criteria goes here])
      {
        Sitecore.Context.ClientPage.ClientResponse.YesNoCancel("Are you sure you want to continue?", "500", "200");
        [Based on results from the YesNoCancel then potentially cancel the Item Save or show them another dialog]
      }
    }
}

Should I be using a different method? I see that there is also ShowModalDialog and ShowPopUp and ShowQuestion, etc. I can't seem to find any documentation on these. Also I am not even sure if this is the correct way to do something like this.

Answer 1

The process goes something like this (I should note that I've never tried this from the item:saving event, however, I believe it should work):

1. Within the item:saving event, invoke a dialog processor in the client pipeline, and pass it a set of arguments.
2. The processor does one of two things; displays the dialog, or consumes the response.
3. When a response is received, the processor consumes it and there you can perform your actions.

Here is an example that demonstrates the steps above:

private void StartDialog()
{
    // Start the dialog and pass in an item ID as an argument
    ClientPipelineArgs cpa = new ClientPipelineArgs();
    cpa.Parameters.Add("id", Item.ID.ToString());

    // Kick off the processor in the client pipeline
    Context.ClientPage.Start(this, "DialogProcessor", cpa);
}

protected void DialogProcessor(ClientPipelineArgs args)
{
    var id = args.Parameters["id"];

    if (!args.IsPostBack)
    {
        // Show the modal dialog if it is not a post back
        SheerResponse.YesNoCancel("Are you sure you want to do this?", "300px", "100px");

        // Suspend the pipeline to wait for a postback and resume from another processor
        args.WaitForPostBack(true);
    }
    else
    {
        // The result of a dialog is handled because a post back has occurred
        switch (args.Result)
        {
            case "yes":

                var item = Context.ContentDatabase.GetItem(new ID(id));
                if (item != null)
                {
                    // TODO: act on the item

                    // Reload content editor with this item selected...
                    var load = String.Format("item:load(id={0})", item.ID);
                    Context.ClientPage.SendMessage(this, load);
                }

                break;

            case "no":

                // TODO: cancel ItemSavingEventArgs

                break;

            case "cancel":
                break;
        }
    }
}