/// <summary>
/// Generates a document id using the registered conventions, such as the Raven HiLo generator.
/// Returns the id without applying it to any particular entity, thus allowing you to pre-generate the id.
/// Useful for detached operations, such as in CQRS. For example, the id could be generated ahead of time,
/// returned to the caller, then used in a command message. The entity would then be created in a command
/// handler, using the id from the message. There are other scenarios that this can also be useful.
/// </summary>
/// <typeparam name="T">The entity type.</typeparam>
/// <param name="session">The current session.</param>
/// <returns>The generated string id.</returns>
public static string GenerateIdFor <T>(this IAdvancedDocumentSessionOperations session)
{
// An entity instance is required to generate a key, but we only have a type.
// We might not have a public constructor, so we must use reflection.
var entity = Activator.CreateInstance(typeof(T), true);
// Generate an ID using the commands and conventions from the current session
var conventions = session.DocumentStore.Conventions;
var databaseName = session.GetDatabaseName();
var databaseCommands = session.GetDatabaseCommands();
return(conventions.GenerateDocumentKey(databaseName, databaseCommands, entity));
}
/// <summary>
/// Checks the database to see if a document with the id specified exists.
/// </summary>
/// <param name="session">The advanced session instance for a particular database.</param>
/// <param name="key">The document key.</param>
/// <returns>True if the document exists, false otherwise.</returns>
public static bool DocumentExists(this IAdvancedDocumentSessionOperations session, string key)
{
return(session.GetDatabaseCommands().DocumentExists(key));
}