ValidateContactAssignmentRelationship

/// <summary>
/// Validates that the plugin context contains a valid tt_Contact_tt_Assignment relationship,
/// and extracts the contact and assignment references.
/// </summary>
public bool ValidateContactAssignmentRelationship(IPluginExecutionContext context, ITracingService tracingService, out EntityReference contact, out EntityReference assignment)
{
    contact = null;
    assignment = null;

    // Check if the relationship is correct
    if (!(context.InputParameters["Relationship"] is Relationship rel) ||
        !string.Equals(rel.SchemaName, "tt_Contact_tt_Assignment", StringComparison.OrdinalIgnoreCase))
    {
        return false;
    }

    // Validate presence of required parameters
    if (!(context.InputParameters["Target"] is EntityReference target) ||
        !(context.InputParameters["RelatedEntities"] is EntityReferenceCollection related) ||
        related.Count == 0)
    {
        tracingService.Trace("Missing Target or RelatedEntities parameters");
        return false;
    }

    // Ensure correct entity types
    if (target.LogicalName != "contact" || related[0].LogicalName != "tt_assignment")
    {
        tracingService.Trace("Entity type mismatch");
        return false;
    }

    // Assign output values
    contact = target;
    assignment = related[0];
    return true;
}