The message pipeline model defines a parameter collection of custom data values in the execution context that is passed through the pipeline and shared among registered plug-ins, even from different 3rd party developers. This collection of data can be used by different plug-ins to communicate information between plug-ins and enable chain processing where data processed by one plug-in can be processed by the next plug-in in the sequence and so on. This feature is especially useful in pricing engine scenarios where multiple pricing plug-ins pass data between one another to calculate the total price for a sales order or invoice. Another potential use for this feature is to communicate information between a plug-in registered for a pre-event and a plug-in registered for a post-event.
The name of the parameter that is used for passing information between plug-ins is SharedVariables. This is a collection of key\value pairs. At run time, plug-ins can add, read, or modify properties in the SharedVariables collection. This provides a method of information communication among plug-ins.
This sample shows how to use SharedVariables to pass data from a pre-event registered plug-in to a post-event registered plug-in.
It is important that any type of data added to the shared variables collection be serializable otherwise the server will not know how to serialize the data and plug-in execution will fail.
For a plug-in registered in stage 20 or 40, to access the shared variables from a stage 10 registered plug-in that executes on create, update, delete, or by a RetrieveExchangeRateRequest, you must access the ParentContext.SharedVariables collection. For all other cases, IPluginExecutionContext.SharedVariables contains the collection.
The name of the parameter that is used for passing information between plug-ins is SharedVariables. This is a collection of key\value pairs. At run time, plug-ins can add, read, or modify properties in the SharedVariables collection. This provides a method of information communication among plug-ins.
This sample shows how to use SharedVariables to pass data from a pre-event registered plug-in to a post-event registered plug-in.
using System; // Microsoft Dynamics CRM namespace(s) using Microsoft.Xrm.Sdk; namespace Microsoft.Crm.Sdk.Samples { /// <summary> /// A plug-in that sends data to another plug-in through the SharedVariables /// property of IPluginExecutionContext. /// </summary> /// <remarks>Register the PreEventPlugin for a pre-event and the /// PostEventPlugin plug-in on a post-event. /// </remarks> public class PreEventPlugin : IPlugin { public void Execute(IServiceProvider serviceProvider) { // Obtain the execution context from the service provider. Microsoft.Xrm.Sdk.IPluginExecutionContext context = (Microsoft.Xrm.Sdk.IPluginExecutionContext) serviceProvider.GetService(typeof(Microsoft.Xrm.Sdk.IPluginExecutionContext)); // Create or retrieve some data that will be needed by the post event // plug-in. You could run a query, create an entity, or perform a calculation. //In this sample, the data to be passed to the post plug-in is // represented by a GUID. Guid contact = new Guid("{74882D5C-381A-4863-A5B9-B8604615C2D0}"); // Pass the data to the post event plug-in in an execution context shared // variable named PrimaryContact. context.SharedVariables.Add("PrimaryContact", (Object)contact.ToString()); } } public class PostEventPlugin : IPlugin { public void Execute(IServiceProvider serviceProvider) { // Obtain the execution context from the service provider. Microsoft.Xrm.Sdk.IPluginExecutionContext context = (Microsoft.Xrm.Sdk.IPluginExecutionContext) serviceProvider.GetService(typeof(Microsoft.Xrm.Sdk.IPluginExecutionContext)); // Obtain the contact from the execution context shared variables. if (context.SharedVariables.Contains("PrimaryContact")) { Guid contact = new Guid((string)context.SharedVariables["PrimaryContact"]); // Do something with the contact. } } } }
For a plug-in registered in stage 20 or 40, to access the shared variables from a stage 10 registered plug-in that executes on create, update, delete, or by a RetrieveExchangeRateRequest, you must access the ParentContext.SharedVariables collection. For all other cases, IPluginExecutionContext.SharedVariables contains the collection.
