Plugin Extensions: Shorten Your Code

There are some lines of code in plugins and workflows that I've written too many times.

1. Getting an attribute

Before we get an entity's attribute, we always check that the entity first contains the attribute. This is because attempting to access the value of an attribute that doesn't exist throws a NullReferenceException. Here's an example that gets the first name of a contact:

	if (contact.Attributes.Contains("firstname"))
	{
	firstName = contact.GetAttributeValue<string>("firstname");
	}

view raw GetContactName.cs hosted with ❤ by GitHub

2. Initialising plugin variables

The following code gets the basic objects needed to run a decent plugin. Look how long-winded it is!

	// Extract the tracing service for use in debugging sandboxed plug-ins.
	ITracingService tracingService = (ITracingService)serviceProvider.GetService(typeof(ITracingService));
	// Obtain the execution context from the service provider.
	IPluginExecutionContext context = (IPluginExecutionContext)serviceProvider.GetService(typeof(IPluginExecutionContext));
	// Obtain the organization service reference.
	IOrganizationServiceFactory serviceFactory = (IOrganizationServiceFactory)serviceProvider.GetService(typeof(IOrganizationServiceFactory));
	IOrganizationService service = serviceFactory.CreateOrganizationService(context.UserId);

view raw PluginInitialisation.cs hosted with ❤ by GitHub

How to shorten things: write extension methods

Create a separate, static class called Extensions.cs. Note the namespace your class is in. If it's in a different namespace to your plugins, you must add a using statement at the top of your plugin classes.

Here's an example extension method that allows the simplification of 1. from above:

	public static T GetValueOrDefault<T>(this Entity entity, string key)
	{
	try
	{
	object value = default(T);
	if (entity != null && !string.IsNullOrEmpty(key) && entity.Contains(key))
	{
	value = entity.GetAttributeValue<T>(key);
	}
	return (T)value;
	}
	catch
	{
	return default(T);
	}
	}

view raw GetValueOrDefault.cs hosted with ❤ by GitHub

It can be used as follows. Note that we no longer need to check if an entity contains an attribute.

var name = contact.GetValueOrDefault<string>("firstname");

view raw GetContactName.cs hosted with ❤ by GitHub

Here's an extension method that shortens the initialisation of plugin variables:

	public static T GetService<T>(this IServiceProvider serviceProvider)
	{
	return (T)serviceProvider.GetService(typeof(T));
	}

view raw GetService.cs hosted with ❤ by GitHub

Here's how we can now initialise the same variables as shown in 2. from above:

	var tracingService = serviceProvider.GetService<ITracingService>();
	var context = serviceProvider.GetService<IPluginExecutionContext>();
	var serviceFactory = serviceProvider.GetService<IOrganizationServiceFactory>();

view raw PluginInitialisationShort.cs hosted with ❤ by GitHub

Much cleaner!