Important!!! How to Validate Communication Options (MobilePhone, Email)

Hi Team,

I'm currently working on implementing validation for fields like MobilePhone, Email, and HomePhone under the Communication Options section on the Contact_FormPage.

However, I couldn’t find any relevant component or configuration in the Contact_FormPage source code that would allow me to add validation using handler or validator methods directly.

I considered using an Entity Event Listener to handle the validation logic, but I noticed that an event handler file already exists in the CrtBase package. Since this file is part of a system package, I’m unable to modify it.

(source-code)

namespace Terrasoft.Configuration
{
    using System;
    using Terrasoft.Common;
    using Terrasoft.Core;
    using Terrasoft.Core.DB;
    using Terrasoft.Core.Entities;
    using Terrasoft.Core.Entities.Events;
    using Terrasoft.Core.ExternalUsers;
    using Terrasoft.Core.Factories;

    #region Class: ContactCommunicationEventListener

    [EntityEventListener(SchemaName = "ContactCommunication")]
    public class ContactCommunicationEventListener: BaseEntityEventListener
    {

        #region Methods: Private

        private bool GetIsExternalUserCommunication(Guid contactId, UserConnection userConnection) {
            var select = new Select(userConnection)
                    .Count("Id")
                .From("SysAdminUnit")
                .Where("ContactId").IsEqual(Column.Parameter(contactId))
                .And("ConnectionType").IsEqual(Column.Parameter(UserType.SSP)) as Select;
            var externalUsersCount = select.ExecuteScalar();
            return externalUsersCount != 0;
        }

        #endregion

        #region Methods: Public

        public override void OnSaving(object sender, EntityBeforeEventArgs e) {
            base.OnSaving(sender, e);
            var entity = (Entity)sender;
            var communicationTypeId = entity.GetTypedColumnValue("CommunicationTypeId");
            if (communicationTypeId != Guid.Parse(CommunicationTypeConsts.EmailId)) {
                return;
            }
            var contactId = entity.GetTypedColumnValue("ContactId");
            var userConnection = entity.UserConnection;
            if (!GetIsExternalUserCommunication(contactId, userConnection)) {
                return;
            }
            var email = entity.GetTypedColumnValue("Number");
            var emailValidator = ClassFactory.Get();
            var isEmailValid = emailValidator.IsValidEmailDomainForExternalUser(email);
            if (!isEmailValid) {
                string message = new LocalizableString(userConnection.ResourceStorage,
                    "ContactCommunicationEventListener", "LocalizableStrings.ErrorMessage.Value");
                throw new SSPRestrictedEmailDomainException(message);
            }
        }

        #endregion

    }

    #endregion

}

Could you please advise on:

• The recommended approach to implement validation for these communication fields?
• Whether there’s a supported way to override or extend existing entity event logic from a system package?