/// <summary>
/// Wraps and processes the supplied query for deferred evaluation
/// </summary>
/// <param name="query"></param>
/// <param name="config"></param>
/// <returns></returns>
public static IQueryable Wrap(IQueryable query, LinqDeferConfiguration config)
{
var provider = new DeferProvider(query.Provider, config);
var wrappedQuery = provider.CreateQuery(query.Expression);
return(wrappedQuery);
}
/// <summary>
/// Causes the preceeding query expression to be searched for instances of calls to
/// Defer.Eval() and transformed.
/// The query will run as usual, but with expressions with Defer.Eval() being evaluated
/// after the required information is retrieved using the underlying provider.
/// This method performs materialisation (the query will be run). The underlying IQueryable
/// can be retrieved by using DeferProvider.Wrap directly.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="query"></param>
/// <param name="config"></param>
/// <returns></returns>
public static IEnumerable <T> ThenDoDeferred <T>(this IQueryable <T> query, LinqDeferConfiguration config = null)
{
config = config ?? LinqDeferConfiguration.Default;
var wrappedQuery = DeferProvider.Wrap(query, config);
var materialisedResults = wrappedQuery.ToList();
return(materialisedResults);
}
/// <summary>
/// Creates a new instance of DeferWrappedQuery
/// </summary>
/// <param name="provider">The DeferProvider instance to use</param>
/// <param name="expression">The untransformed source expression</param>
public DeferWrappedQuery(DeferProvider provider, Expression expression)
{
_provider = provider;
_expression = expression;
}