MS Dynamics CRM Associate/Disassociate message Plugin

In MS CRM Plugin Associate/Disassociate messages are used only for N-N relationship adding/removal of a associate record.

Note: With 1-N relationship you will have to use Update message with filter by relationship lookup.
For handling of deleting of records from sub-grid you will have to handle Delete message.
For example if you have grid of child records on parent record then if the grid is containing 1:n relationship child records then no need to write plugin on associate and disassociate messages for any logic. For that Update message will work.

In MS CRM Plugins, the Associate & Disassociate messages behave little bit different than other messages.

When you register a plugin on Associate message, you have to leave "Primary"and "Secondary" entities as 'none'.

Since we don’t provide entity names, the registered Plug-in step triggers on all "Associate"  & "Disassociate" operations, so we have to check few conditions to let the “Association”  & "Disassociate" trigger happen only between intended entities. You can use the below code template for Associate or Disassociate plugins.

using System;

using System.Collections;

using System.Text;

using Microsoft.Xrm.Sdk;

using System.Web;

using System.Xml;

using System.Diagnostics;

using Microsoft.Xrm.Sdk.Query;

using Microsoft.Xrm.Sdk.Client;

using Microsoft.Crm.Sdk.Messages;

namespace Termination

{

    public class Delegates:IPlugin

    {

        public void Execute(IServiceProvider serviceProvider)

        {

            IPluginExecutionContext context = (IPluginExecutionContext)serviceProvider.GetService(typeof(IPluginExecutionContext));

            if (context.Depth > 1)

                return;

            IOrganizationServiceFactory serviceFactory = (IOrganizationServiceFactory)serviceProvider.GetService(typeof(IOrganizationServiceFactory));

            IOrganizationService service = serviceFactory.CreateOrganizationService(context.UserId);

            ITracingService trace = (ITracingService)serviceProvider.GetService(typeof(ITracingService));

            EntityReference targetEntity = null;

            string relationshipName = string.Empty;

            EntityReferenceCollection relatedEntities = null;

            EntityReference relatedEntity = null;

            Entity eventBooking = null;

            Guid eventEntID = Guid.Empty;

            EntityReferenceCollection eqEntites = null;

            Relationship relationshipEventContact = null;

            try

            {

                #region Associate & Disassociate

                if (context.MessageName.ToLower() == "associate" || context.MessageName.ToLower() == "disassociate")

                {

                    // Get the “Relationship” Key from context

                    if (context.InputParameters.Contains("Relationship"))

                    {

                       // Get the Relationship name for which this plugin fired

                        relationshipName = ((Relationship)context.InputParameters["Relationship"]).SchemaName;                      

                    }

                    // Check the "Relationship Name" with your intended one

                    if (relationshipName != "new_new_eventbooking_contact")

                    {                     

                    return;                 

                    }

                     // Get Entity EventBooking reference from Target Key from context

                    if (context.InputParameters.Contains("Target") && context.InputParameters["Target"] is EntityReference)  {

                        targetEntity = (EntityReference)context.InputParameters["Target"];

                        eventBooking = service.Retrieve("new_eventbooking", targetEntity.Id, new ColumnSet("new_eventname"));

                        if (eventBooking.Attributes.Contains("new_eventname"))

                        {                         

                            var eventEnt = (EntityReference)eventBooking["new_eventname"];

                             eventEntID = eventEnt.Id;

                        }

                       }

                     // Get Entity Contact reference from RelatedEntities Key from context

                    if (context.InputParameters.Contains("RelatedEntities") && context.InputParameters["RelatedEntities"] is EntityReferenceCollection)

                    {

                        relatedEntities = context.InputParameters["RelatedEntities"] as EntityReferenceCollection;

                        relatedEntity = relatedEntities[0];

                        eqEntites = new EntityReferenceCollection();

                        eqEntites.Add(new EntityReference("contact", relatedEntities[0].Id));                     

                    }

                    if (eqEntites != null && eventEntID != null)

                    {

                        relationshipEventContact = new Relationship("new_new_events_contacts");

                        if (context.MessageName.ToLower() == "associate")

                        {

                            service.Associate("new_event", eventEntID, relationshipEventContact, eqEntites);

                        }

                        if (context.MessageName.ToLower() == "disassociate")

                        {

                            service.Disassociate("new_event", eventEntID, relationshipEventContact, eqEntites);

                        }

                        trace.Trace("Event-Delegate Associate & Dissassociate Plugin copleted Successfully");

                    }

                    else

                    {

                        trace.Trace("Event-Delegate Associate & Dissassociate Plugin not completed Successfully");

                    }

                }

                #endregion

            }

            catch (Exception ex)

            {

                trace.Trace(string.Format("Event-Delegate Associate & Dissassociate Plugin error: {0}", new[] { ex.ToString() }));

            }

        }

    }

}