How to trigger a plugin for a many to many relationship

The blog will explain “ How to trigger a plugin for many to many (N:N) relationship. For this blog, I have created a new N:N relationship between account and contact entity. I am displaying this relationship just in account entity. The following screen shot is displaying the properties of the relationship.

To trigger a plugin on association of 2 entities in a n:n relationship, we will use associate plugin message. I am using the developer’s toolkit for writing code from last 6 months. The problem is developer’s toolkit does not support “Associate” message. To create a plugin in developer’s toolkit, you need to choose primary entity and to use “Associate” message primary entity and secondary entity has to be “none”. There is a workaround to register  plugin step on “Associate” message. Here are the steps.

1. Follow the steps in this blog on how to create a plugin using developer’s toolkit.
2. In the step 12th of above-mentioned blog, replace the function “ExecutePostAccountCreate” with the following code

   protected void ExecutePostAccount(LocalPluginContext localContext)
   {
   
       if (localContext == null)
       {
           throw new ArgumentNullException("localContext");
       }
   
       // TODO: Implement your custom Plug-in business logic.
       // Obtain the execution context from the service provider.
       IPluginExecutionContext context = localContext.PluginExecutionContext;
       IOrganizationService service = localContext.OrganizationService;
       ITracingService tracingService = localContext.TracingService;
   
       try{
       // The InputParameters collection contains all the data passed in the message request.
       if (!context.InputParameters.Contains("Target")) { return; }
   
       EntityReference ef = (EntityReference)context.InputParameters["Target"];
       if (ef.LogicalName != "account") { return; }
   
       Relationship relationship = (Relationship)context.InputParameters["Relationship"];
       if (relationship.SchemaName != "new_account_contact") { return; }
   
       // Get Related Entities 
       EntityReferenceCollection re = (EntityReferenceCollection)context.InputParameters["RelatedEntities"];
   
       foreach (EntityReference rel in re)
       {
   
           Entity relatedEntity = service.Retrieve("contact", rel.Id, new ColumnSet("address1_city"));
           string city = (string)relatedEntity.Attributes["address1_city"];
           if (city=="Sydney")
           {
               //create a task
               Entity task = new Entity("task");
               task["subject"] = "A new contact from sydney is added to the account";
               task["regardingobjectid"] = ef;
               task["description"] = "A new contact from sydney is added to the account";
               // Create the task in Microsoft Dynamics CRM.
               service.Create(task);
   
           }
       }//endfor
       }
       catch (FaultException ex)
       {
           tracingService.Trace(ex.Message.ToString());
           throw new InvalidPluginExecutionException("An error occurred in the plug-in.", ex);
       }
   
   }//end function
   

3. Add the following reference to your plugin class.

   using Microsoft.Xrm.Sdk.Query;

4. The above code will create a task, when we add a contact with “address1_city” field equal to “Sydney” to an account. Just remember we are relating a contact to account using N:N relationship.
5. Now change the RegisterFile.crmregister file  to register on an “Associate” message. Open the file and look for your plugin definition. It will look something like the following code.

   <Plugin Description="Plug-in to PostAccountCreate" FriendlyName="PostAccountCreate" Name="CRM2011PluginSeries.Plugins.PostAccountCreate" Id="420419bd-9fe7-404e-a5e3-afa582f21dd3" TypeName="CRM2011PluginSeries.Plugins.PostAccountCreate">
             <Steps>
               <clear />
               <Step CustomConfiguration="" Name="PostAccountCreate" Description="Post-Operation of Account Create" Id="b248f264-2b3f-e111-ab54-00155d32042e" MessageName="Create" Mode="Synchronous" PrimaryEntityName="account" Rank="1" SecureConfiguration="" Stage="PostOutsideTransaction" SupportedDeployment="ServerOnly">
                 <Images />
               </Step>
             </Steps>
           </Plugin>

6. Now change the MessageName="Create" to MessageName="Associate" and PrimaryEntityName="account" to PrimaryEntityName="".
7. Save the changes and deploy the plugin.
8. If you get any errors during deployment, just deploy the plugin using plugin registeration tool. Don't forget to leave the "PrimaryEntityName" = none.
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