> For the complete documentation index, see [llms.txt](https://comunity.gitbook.io/learning.comunityplatform/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://comunity.gitbook.io/learning.comunityplatform/26.x/toolkit-guides/communications/triggering-the-communication-service.md).

# Triggering the Communication Service

The [CommsService.TriggerEvent()](#commsservice.trigger) function has six required arguments which are outlined in the table below:

<table><thead><tr><th width="246">Argument</th><th width="177.56342166234055">Type/Return Type</th><th>Description/Typical Value</th></tr></thead><tbody><tr><td>appName</td><td>String</td><td><code>Config.AppName()</code></td></tr><tr><td>eventName</td><td>String</td><td>A unique name of your event defined under <strong>Configuration</strong> -> <strong>Communication Services</strong></td></tr><tr><td>payload</td><td>JSON</td><td>Use the <code>ComsServices.JsonSerialize()</code> function to serialise the current instance of your class into JSON</td></tr><tr><td>url</td><td>String</td><td><code>Config.ComsService()</code></td></tr><tr><td>userName</td><td>String</td><td><code>Config.UserName()</code></td></tr><tr><td>password</td><td>String</td><td><code>Config.Password()</code></td></tr></tbody></table>

To trigger the Communication Service, follow these steps:

1. Open your project and navigate to **Data**.
2. Select **Diagram** or **List** to view your **Data** model.
3. Locate and select the entity for which you want to configure communications. In a **Diagram** view, click on the entity's header section with a grey background colour. An active entity is identified by a blue border, and none of its entity fields are active (active entity fields have a blue background colour).&#x20;
4. This action will open a properties dialog that displays the entity's global properties.
5. Within the properties dialog, locate **Custom Code** you can expand the text editor by clicking on the ![](/files/fLWGidRUfWgqvHCDslfo) icon.  &#x20;
6. Now, you need to identify and select a change interceptor to initiate the `ComsService.Trigger()` function. If the custom code has already been auto-generated, you can proceed with selecting an appropriate change interceptor. However, if the custom code hasn't been auto-generated, you have the option to define your own partial class. Within this class, you can invoke the `ComsService.Trigger()` function using the interceptor of your choice as show&#x6E;*(check line 66 in the code block below)*:

{% code lineNumbers="true" %}

```csharp
// Copyright (c) ComUnity 2017

using ComUnity.DataServices;
using ComUnity.DataServices.DomainUtility.Exceptions;
using ComUnity.DataServices.DomainUtility.Security;
using ComUnity.DataServices.ServiceUtility;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Data.Entity;
using System.Data.Entity.ModelConfiguration.Conventions;
using System.Data.Services;
using System.Data.Services.Providers;
using System.Linq;
using System.Linq.Expressions;
using System.Web;

namespace CaseComms.Models
{
	public partial class Case
	{
		// START auto-generated - CTOR
		public Case() : base()
		{
		// END auto-generated, add custom code below this line
		
		}
		
		// START auto-generated - OnAdd
		public override void OnAdd(CaseCommsContext context)
		{
			base.OnAdd(context);
			CaseStatus status = context.Set<CaseStatus>().FirstOrDefault();
			Status = status ?? throw new GeneralException(400, "General", "No status defined in database!");
			context.SaveChanges();
			DateTime dt = DateTime.Now;
			string refString = dt.ToShortDateString() + "-" + CaseId;
			ReferenceNumber = refString;
			var toAddress = Config.CaseEmail();
			var an = Config.AppName();
			var cs = Config.ComsService();
			if (toAddress != null && an != null && cs != null)
			{
			    var payload = ComsServices.JsonSerialize(this);
			    ComsServices.TriggerEvent(an, "OnAddCase", payload, cs, Config.ComsServiceUsername(), Config.ComsServicePassword());
			}
		
		// END auto-generated, add custom code below this line
		
		}
		
		// START auto-generated - OnChange
		public override void OnChange(CaseCommsContext context)
		{
			base.OnChange(context);
			int prevStatus = context.Entry(this).OriginalValues.GetValue<int>("StatusCaseStatusId");
			if (StatusCaseStatusId != prevStatus)
			{
				var an = Config.AppName();
				var cs = Config.ComsService();
				if (an != null && cs != null)
				{
					var payload = ComsServices.JsonSerialize(this);
					// ComsServices.TriggerEvent() invocation
					ComsServices.TriggerEvent(an, "OnChangeCase", payload, cs, Config.ComsServiceUsername(), Config.ComsServicePassword());
				}
			}
		
		// END auto-generated, add custom code below this line
		
		}
		
		// START auto-generated - OnDelete
		public override void OnDelete(CaseCommsContext context)
		{
			base.OnDelete(context);
		// END auto-generated, add custom code below this line
		
		}
		
		// START auto-generated - Filter start
		public static Expression<Func<Case,bool>> Filter(CaseCommsContext context)
		{
			Expression<Func<Case, bool>> filter = o => true;
		// END auto-generated, add custom code below this line
			
		// START auto-generated - Filter end
			return filter;
		}
		// END auto-generated, add custom code below this line
		
		// START auto-generated - OnSeed
		public static void OnSeed(CaseCommsContext context)
		{
		// END auto-generated, add custom code below this line
		
		}
	}
}

```

{% endcode %}

After triggering the Communication Service by adding the code to invoke the `ComsService.Trigger()` function, the next step is to configure the event action and templates.