Step By Step Creating a Simple Plugin

So before creating a plugin, You need to understand two things.

  1. What is a Plugin?
  2. When to use the Plugins?

1. What is a Plugin?

A plug-in is custom business logic(code) that you can integrate with Dynamics CRM to modify or augment the standard behavior of the platform.

In simple word, it is a piece of code used to enhance the ability to perform the task which we can not do by of box customization.

Plugins are event handlers for the events fired by Microsoft Dynamics CRM.

You can register plug-in against events using Plugin registration tool or using Solutions.

The plug-in runs in CRM server synchronous(in real time) or asynchronously(in the background) depends upon how they are registered with CRM server.

2. When to use the Plugins?

Plugins Vs JavaScript

  • When Server Side execution of business logic is needed.

Plugins Vs Workflows

  • Workflows can be used to trigger for a limited number of messages(events). A plugin can be executed for all of the messages of the CRM system and can be synchronous and asynchronous.
  • When the performance is considered.

Let’s Begin with An Example:

A plug-in is a custom business logic that integrates with Microsoft Dynamics CRM to modify or extend the standard behavior of the platform. Plug-ins act as event handlers and are registered to execute on a particular event in CRM. Plugins are written in either C# or VB and can run either in synchronous or asynchronous mode.

Some scenarios where you would write a plugin are −

  • You want to execute some business logic such as updating certain fields of a record or updating related records, etc. when you create or update a CRM record.
  • You want to call an external web service on certain events such as saving or updating a record.
  • You want to dynamically calculate the field values when any record is opened.
  • You want to automate processes such as sending e-mails to your customers on certain events in CRM.

Event Framework

The Event Processing Framework in CRM processes the synchronous and asynchronous plugin requests by passing it to the event execution pipeline. Whenever an event triggers a plugin logic, a message is sent to the CRM Organization Web Service where it can be read or modified by other plugins or any core operations of the platform.

Plugin Pipeline Stages

The entire plugin pipeline is divided into multiple stages on which you can register your custom business logic. The pipeline stage specified indicates at which stage of the plugin execution cycle, your plugin code runs. Out of all the specified pipeline stages in the following table, you can register your custom plugins only on Pre- and Post-events. You can’t register plugins on Platform Core Main Operations.

EventStage NameStage Name
Pre-EventPre-validationStage in the pipeline for plug-ins that are to execute before the main system operation. Plug-ins registered in this stage may execute outside the database transaction.
Pre-EventPre-operationStage in the pipeline for plug-ins that are to executed before the main system operation. Plugins registered in this stage are executed within the database transaction.
Platform Core OperationMainOperationIntransaction,the main operation of the system, such as create, update, delete, and so on. No custom plug-ins can be registered in this stage. For internal use only.
Post-EventPost-operationStage in the pipeline for plug-ins which are to executed after the main operation. Plug-ins registered in this stage are executed within the database transaction.

Whenever the CRM application invokes an event (like saving or updating a record), the following sequence of actions takes place −

  • The event triggers a Web service call and the execution is passed through the event pipeline stages (pre-event, platform core operations, post-event).
  • The information is internally packaged as an OrganizationRequest message and finally sent to the internal CRM Web service methods and platform core operations.
  • The OrganizationRequest message is first received by pre-event plugins, which can modify the information before passing it to platform core operations. After the platform core operations, the message is packaged as OrganizationResponse and passed to the post-operation plugins. The post operations plugins can optionally modify this information before passing it to the async plugin.
  • The plugins receive this information in the form of context object that is passed to the Execute method after which the further processing happens.
  • After all the plugin processing completes, the execution is passed back to the application which triggered the event.

Plugin Messages

Messages are the events on which the plugin (or business logic) is registered. For example, you can register a plugin on Create Message of Contact entity. This would fire the business logic whenever a new Contact record is created.

For custom entities, following are the supported messages based on whether the entity is user-owned or organization-owned.

Message NameOwnership Type
AssignUser-owned entities only
CreateUser-owned and organization-owned entities
DeleteUser-owned and organization-owned entities
GrantAccessUser-owned entities only
ModifyAccessUser-owned entities only
RetrieveUser-owned and organization-owned entities
RetrieveMultipleUser-owned and organization-owned entities
RetrievePrincipalAccessUser-owned entities only
RetrieveSharedPrincipalsAndAccessUser-owned entities only
RevokeAccessUser-owned entities only
SetStateUser-owned and organization-owned entities
SetStateDynamicEntityUser-owned and organization-owned entities
UpdateUser-owned and organization-owned entities

For default out-of-the-box entities, there are more than 100 supported messages. Some of these messages are applicable to all the entities while some of them are specific to certain entities. You can find the complete list of supported message in an excel file inside the SDK: SDK\Message-entity support for plug-ins.xlsx

Writing Plugin

In this section, we will learn the basics of writing a plugin. We will be creating a simple plugin that creates a Task activity to follow-up with the customer whenever a new customer is added to the system, i.e. whenever a new Contact record is created in CRM.

First of all, you would need to include the references to Microsoft.Xrm.Sdknamespace. The CRM SDK contains all the required SDK assemblies. Assuming that you have already downloaded and installed the SDK in Chapter 2, open Visual Studio. Create a new project of type Class Library. You can name the project as SamplePlugins and click OK.

Mscrm Plugin Create vs Solution

Add the reference of Microsoft.Xrm.Sdk assembly to your project. The assembly is present in SDK/Bin.

Mscrm Plugin Add Solution Reference

Now, create a class named PostCreateContact.cs and extend the class from IPlugin. Till now, your code will look something like the following.

Mscrm Plugin Sample Code

You will also need to add reference to System.Runtime.Serialization. Once you have added the required references, copy the following code inside the PostCreateContact class.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.Xrm.Sdk;

namespace SamplePlugins {
   public class PostCreateContact:IPlugin {
      /// A plug-in that creates a follow-up task activity when a new account is created.
      /// Register this plug-in on the Create message, account entity,
      /// and asynchronous mode.

      public void Execute(IServiceProviderserviceProvider) {
         // Obtain the execution context from the service provider.
         IPluginExecutionContext context =(IPluginExecutionContext)
            serviceProvider.GetService(typeof(IPluginExecutionContext));

         // The InputParameters collection contains all the data
            passed in the message request.

         if(context.InputParameters.Contains("Target")&&
            context.InputParameters["Target"]isEntity) {
            
            // Obtain the target entity from the input parameters.
            Entity entity = (Entity)context.InputParameters["Target"];
            try {
               
               // Create a task activity to follow up with the account customer in 7 days
               Entity followup = new Entity("task");
               followup["subject"] = "Send e-mail to the new customer.";
               followup["description"] =
                  "Follow up with the customer. Check if there are any new issues
                  that need resolution.";
               
               followup["scheduledstart"] = DateTime.Now;
               followup["scheduledend"] = DateTime.Now.AddDays(2);
               followup["category"] = context.PrimaryEntityName;

               // Refer to the contact in the task activity.
               if(context.OutputParameters.Contains("id")) {
                  Guid regardingobjectid = new Guid(context.OutputParameter
                     s["id"].ToString());
                  string regardingobjectidType = "contact";
                  followup["regardingobjectid"] = 
                     new EntityReference(rega rdingobjectidType,regardingobjectid);
               }
               
               // Obtain the organization service reference.
               IOrganizationServiceFactory serviceFactory =
                  (IOrganizationSer viceFactory)serviceProvider.GetService
                  (typeof(IOrganizationServiceFactory));
               IOrganizationService service = 
                  serviceFactory.CreateOrganizationService(context.UserId);

               // Create the followup activity
               service.Create(followup);
            } catch(Exception ex) {
               throw new InvalidPluginExecutionException(ex.Message);
            }
         }
      }
   }
}

Following is a step-by-step explanation of what this code does −

Step 1 − Implements the Execute method by taking IServiceProvider object as its parameter. The service provider contains references to many useful objects that you are going to use within a plugin.

Step 2 − Obtains the IPluginExecutionContext object using the GetService method of IServiceProvider.

Step 3 − Gets the target entity’s object from the context object’s InputParameters collection. This Entity class object refers to the Contact entity record on which our plugin would be registered.

Step 4 − It then creates an object of Task entity and sets a proper subject, description, dates, category, and regardingobjectid. The regardingobjectid indicates for which contact record this activity record is being created. You can see that the code gets the id of the parent Contact record using context.OutputParameters and associates it with the Task entity record which you have created.

Step 5 − Create an object of IOrganizationServiceFactory using the IServiceProvider object.

Step 6 − Create an object of IOrganizationService using the IOrganizationServiceFactory object.

Step 7 − Finally, using the Create method of this service object. It creates the follow-up activity which gets saved in CRM.

Signing the Plugin Assembly

This section is applicable only if you are registering your plugin assembly for the first time. You need to sign in the assembly with a key to be able to deploy the plugin. Rightclick the solution and click Properties.

Mscrm Plugin Solution Properties

Select the Signing tab from the left options and check the ‘Sign the assembly’ option. Then, select New from Choose a strong name key file option.

Mscrm Plugin Sign Assembly

Enter the Key file name as sampleplugins (This can be any other name you want). Uncheck the Protect my key file with a password option and click OK. Click Save.

Mscrm Plugin Sign Assembly Add Key

Finally, build the solution. Right Click → Build. Building the solution will generate assembly DLL, which we will use in the next chapter to register this plugin.

Exception Handling in Plugin

More often than not, your plugin logic will need to handle run-time exceptions. For synchronous plugins, you can return an InvalidPluginExecutionException exception, which will show an error dialog box to the user. The error dialog will contain the custom error message that you pass to the Message object of the exception object.

If you look at our code, we are throwing the InvalidPluginExecutionException exception in our catch block.

throw new InvalidPluginExecutionException(ex.Message); 

Conclusion

Plugins are definitely crucial to any custom CRM implementation. In this chapter, we focused on understanding the event framework model, pipeline stages, messages, and writing a sample plugin. In the next chapter, we will register this plugin in CRM and see it working from the end-to-end scenario.

Dynamics 365 CRM Plugin Messages

If you are developing a plugin, sooner or later you will need to do something in a plugin that requires “listening” to more than just Create, Read, Update, and Delete messages.

What is a Message?

If you are new to Dynamics CRM development, a Message word that is used to instruct CRM to do something. As far as I can tell, since the early versions of the CRM SDK used the SOAP protocol exclusively, and SOAP passes messages, the term message became the standard name for CRM internal processing options

If anyone has any other explanation, please let me know and I’ll update the post.

What do you do with Messages?

Messages are what a plugin “listens for” to know when to activate and perform whatever job it was programmed to do.

A Message is associated with a Plugin Step ( internally called a SdkMessageProcessingStep ), which is a pointer that associates your plugin code to a Dynamics CRM internal action.

Inside the Plugin Registration Tool, you may see something like this:

image

As you can see, I have an assembly called ClassLibrary1, within that assembly I have a single plugin, SamplePlugin, and that plugin has two steps:

  1. Create of a queue item
  2. Create an email

Create is the Message.

How do I make it GO?

So, how do you, as a plugin developer, figure out what message you need to use to properly configure your plugin?

Well, for the most part, it’s pretty simple: You select the CRM operation you are interested in intercepting then select Entity that will be associated with that Message.

Here is how the configuration looks within the Plugin Registration Tool:

image

But what if I don’t know what message to use?

Excellent question, and the reason for my article.

The very fine folks in the Dynamics CRM documentation team have created for us, an Excel worksheet that lists all of the messages associated with a CRM Entity.

After you install the CRM SDK, you’ll find the worksheet here:

sdk\tools\message-entity support for plug-ins.xlsx

And here is how it looks:

image

It lists the following information:

  • Message Name
  • Primary Entity
  • Secondary Entity
  • Message Availability
  • Server or
  • Both – for Client and Server
  • Entity Supported Deployment
  • Server or
  • Both – for Client and Server

How do I use it?

Usually, I know what Entity I am going to work with so I start there and filter the Primary Entity-based on that information.

Next, I try and locate the Message Name that I might need. Now, this sounds simple, but in certain cases, it’s really hard to determine what exact message you should connect with.

In that case, I will sometimes create steps that monitor each possible message, connect my debugger to IIS, then execute the CRM operation of interest so that I see what message is actually being passed through to my plugin.

You can find the message in the Execution Context’s MessageName property.

Option 2

A second option is to look in the SDK help file itself for topics like:

Email (E-mail) Entity Messages and Methods

Where you will find information like this:

image

This should be the same (mostly) list of Messages found in the Excel file. Just remove the word “Request” from the end of the Message Name found in the SDK help file and you should have a match.

Conclusion

Well, that’s about it for today. Hopefully, this will help you in your plugin development efforts.