Prevent sending email and show message via plug-in - plugins

Question

I am writing crm2011 plugin in "Email" entity with "Send" Message of Pre_operation. What i want to do is when i click "Send" button in email entity, I do the necessary checking before send. If the checking is not correct, I want to prevent and stop the sending email and show "the alert message" and stop the second plugin(this plugin send email and create the associated entity to convert "Case"). Please give me some suggestion for that plugin?
Should i use pre-Validation stage or Pre_operation state? And how can I return false to stop plugin.
public void Execute(IServiceProvider serviceProvider)
{
try
{
string message = null;
_serviceProvider = serviceProvider;
_context = (IPluginExecutionContext)
serviceProvider.GetService(typeof(IPluginExecutionContext));
_serviceFactory = (IOrganizationServiceFactory)serviceProvider.GetService(typeof(IOrganizationServiceFactory));
_currentUser = _context.UserId;
message = _context.MessageName.ToLower();
if (message == "send")
{
if (_context.InputParameters != null && _context.InputParameters.Contains("EmailId"))
{
object objEmailId = _context.InputParameters["EmailId"];
if (objEmailId != null)
{
_emailId = new Guid(objEmailId.ToString());
FindEmailInfo();
if (_email != null)
{
if (_email.Attributes.Contains("description") && _email.Attributes["description"] != null)//Email descritpion is not null
{
string emaildescription = StripHTML();
//Find KB Article prefix no in system config entity
serviceguideprefix = "ServiceGuidesPrefix";
QueryByAttribute query = new QueryByAttribute("ppp_systemconfig");
query.ColumnSet = new ColumnSet(true);
query.AddAttributeValue(sysconfig_name, serviceguideprefix);
EntityCollection sysconfig = _service.RetrieveMultiple(query);
if (sysconfig.Entities.Count > 0)
{
Entity e = sysconfig.Entities[0];
if (e.Attributes.Contains("ppp_value"))
{
ppp_value = e.Attributes["ppp_value"].ToString();
}
}
if (ppp_value != null && ppp_value != string.Empty)
{
//var matches = Regex.Matches(emaildescription, #"KBA-\d*-\w*").Cast<Match>().ToArray();
var matches = Regex.Matches(emaildescription, ppp_value + #"-\d*-\w*").Cast<Match>().ToArray();
//ReadKBNo(emaildescription);
foreach (Match kbnumber in matches)
{
EntityCollection kbarticlecol = FindKBArticleIds(kbnumber.ToString());
if (kbarticlecol.Entities.Count > 0)
{
Entity kbariticle = kbarticlecol.Entities[0];
if (kbariticle.Attributes.Contains("mom_internalkm"))
{
bool internalserviceguide = (bool)kbariticle.Attributes["mom_internalkm"];
if (internalserviceguide) found = true;
else found = false;
}
else found = false;
}
}
}
if (found)
{
//-----
}
}
}
}
}
}
}
catch (Exception ex)
{
throw new InvalidPluginExecutionException(ex.Message, ex);
}
}

Answer 1

Well stopping the plugin is dead easy you just throw InvalidPluginException, the message you give it will be shown to the user in a alert window. You will have to do this on the pre of the send. In this case I don't think it will matter if its pre-validation or pre-operation.
Edit:
Yes, you should throw an InvalidPluginException even if no exception has happened in code. I accept this isnt what we would normally do, but its the way its meant to work. Msdn has more details: http://msdn.microsoft.com/en-us/library/gg334685.aspx
So for example the code would look like:
public void Execute(IServiceProvider serviceProvider)
{
try
{
//This is where we validate the email send
if(emailIsOkay)
{
//Do something
}
else if(emailIsNotOkay)
{
//Throw and exception that will stop the plugin and the message will be shown to the user (if its synchronous)
throw new InvalidPluginExecutionException("Hello user, your email is not correct!!");
}
}
catch (InvalidPluginExecutionException invalid)
{
//We dont to catch exception for InvalidPluginExecution, so just throw them on
throw;
}
catch (Exception ex)
{
//This exception catches if something goes wrong in the code, or some other process.
throw new InvalidPluginExecutionException(ex.Message, ex);
}
}

Answer 2

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.Crm;
using Microsoft.Xrm.Sdk;
using System.ServiceModel;
using Microsoft.Xrm.Sdk.Query;
using Microsoft.Crm.Sdk.Messages;
using System.Text.RegularExpressions;
using System.Xml.Linq;
namespace SendEmail
{
public class Email : IPlugin
{
public void Execute(IServiceProvider serviceprovider)
{
IPluginExecutionContext context = (IPluginExecutionContext)serviceprovider.GetService(typeof(IPluginExecutionContext));
if (!(context.InputParameters.Contains("Target") && context.InputParameters["Target"] is Entity))
return;
//entity
Entity ent = (Entity)context.InputParameters["Target"];
if (ent.LogicalName != "entityName")//EntityName
throw new InvalidPluginExecutionException("Not a Service Request record! ");
//service
IOrganizationServiceFactory serviceFactory = (IOrganizationServiceFactory)serviceprovider.GetService(typeof(IOrganizationServiceFactory));
IOrganizationService _service = serviceFactory.CreateOrganizationService(context.UserId);
string Email="";
if (ent.Contains("emailidfiled"))
Email = (string)ent["emailidfiled"];
#region email template
QueryExpression query = new QueryExpression()
{
EntityName = "template",
Criteria = new FilterExpression(LogicalOperator.And),
ColumnSet = new ColumnSet(true)
};
query.Criteria.AddCondition("title", ConditionOperator.Equal, "templateName");
EntityCollection _coll = _service.RetrieveMultiple(query);
if (_coll.Entities.Count == 0)
throw new InvalidPluginExecutionException("Unable to find the template!");
if (_coll.Entities.Count > 1)
throw new InvalidPluginExecutionException("More than one template found!");
var subjectTemplate = "";
if (_coll[0].Contains("subject"))
{
subjectTemplate = GetDataFromXml(_coll[0]["subject"].ToString(), "match");
}
var bodyTemplate = "";
if (_coll[0].Contains("body"))
{
bodyTemplate = GetDataFromXml(_coll[0]["body"].ToString(), "match");
}
#endregion
#region email prep
Entity email = new Entity("email");
Entity entTo = new Entity("activityparty");
entTo["addressused"] =Email;
Entity entFrom = new Entity("activityparty");
entFrom["partyid"] = "admin#admin.com";
email["to"] = new Entity[] { entTo };
email["from"] = new Entity[] { entFrom };
email["regardingobjectid"] = new EntityReference(ent.LogicalName, ent.Id);
email["subject"] = subjectTemplate;
email["description"] = bodyTemplate;
#endregion
#region email creation & sending
try
{
var emailid = _service.Create(email);
SendEmailRequest req = new SendEmailRequest();
req.EmailId = emailid;
req.IssueSend = true;
GetTrackingTokenEmailRequest wod_GetTrackingTokenEmailRequest = new GetTrackingTokenEmailRequest();
GetTrackingTokenEmailResponse wod_GetTrackingTokenEmailResponse = (GetTrackingTokenEmailResponse)
_service.Execute(wod_GetTrackingTokenEmailRequest);
req.TrackingToken = wod_GetTrackingTokenEmailResponse.TrackingToken;
_service.Execute(req);
}
catch (Exception ex)
{
throw new InvalidPluginExecutionException("Email can't be saved / sent." + Environment.NewLine + "Details: " + ex.Message);
}
#endregion
}
private static string GetDataFromXml(string value, string attributeName)
{
if (string.IsNullOrEmpty(value))
{
return string.Empty;
}
XDocument document = XDocument.Parse(value);
// get the Element with the attribute name specified
XElement element = document.Descendants().Where(ele => ele.Attributes().Any(attr => attr.Name == attributeName)).FirstOrDefault();
return element == null ? string.Empty : element.Value;
}
}
}