/// <summary>
/// Raises the <see cref="E:BeforeMigration"/> event.
/// </summary>
/// <param name="e">The <see cref="NMigrations.Core.BeforeMigrationEventArgs"/> instance containing the event data.</param>
protected virtual void OnBeforeMigration(BeforeMigrationEventArgs e)
{
if (BeforeMigration != null)
{
BeforeMigration(this, e);
}
}
/// <summary>
/// Applies the specified <paramref name="migration"/> within the
/// specified <paramref name="context"/>.
/// </summary>
/// <param name="migration">The migration to apply.</param>
/// <param name="direction">The migration direction.</param>
/// <param name="context">The context.</param>
protected virtual void ApplyMigration(IMigration migration, MigrationDirection direction, MigrationContext context)
{
//
// Notify environment
//
var beforeArgs = new BeforeMigrationEventArgs(migration.GetVersion(), migration, direction);
OnBeforeMigration(beforeArgs);
if (beforeArgs.Cancel) throw new Exception("environment cancelled migration");
//
// Generate model
//
Database model = new Database(context);
//
// Send SQL statements on flush notification
//
model.FlushChanges += delegate(object sender, EventArgs e)
{
foreach (string sql in context.SqlProvider.GenerateSqlCommands(model))
{
// Notify environment
var beforeSqlArgs = new BeforeSqlEventArgs(sql);
OnBeforeSql(beforeSqlArgs);
if (beforeSqlArgs.Cancel) throw new Exception("environment cancelled migration");
// Execute
SqlProcessor.ProcessMigrationStatement(context, sql);
// Notify environment
var afterSqlArgs = new AfterSqlEventArgs(sql, true);
OnAfterSql(afterSqlArgs);
}
};
//
// Run migration
//
if (direction == MigrationDirection.Up)
migration.Up(model);
else
migration.Down(model);
//
// Flush changes
//
model.Flush();
//
// Memorize migration
//
HistoryRepository.AddItem(context,
new MigrationHistoryItem()
{
Date = DateTime.Now,
Direction = direction,
Version = migration.GetVersion()
}
);
//
// Notify enviroment
//
var afterArgs = new AfterMigrationEventArgs(migration.GetVersion(), migration, direction, true);
OnAfterMigration(afterArgs);
}
