private IQueryable <TEntity> Queryable(
Expression <Func <TEntity, bool> > predicate,
IncludingQuery <TEntity> includingQuery = null,
OrderingQuery <TEntity> orderingQuery = null,
PagingQuery pagingQuery = null)
{
return(DbSet.Where(predicate).Including(includingQuery).Ordering(orderingQuery).Paging(pagingQuery));
}
public async Task <IReadOnlyList <TEntity> > GetAsync(
Expression <Func <TEntity, bool> > predicate,
IncludingQuery <TEntity> includingQuery = null,
OrderingQuery <TEntity> orderingQuery = null,
PagingQuery pagingQuery = null,
CancellationToken cancellationToken = default)
{
return(await Queryable(predicate, includingQuery, orderingQuery, pagingQuery)
.ToListAsync(cancellationToken));
}
public static IQueryable <T> Ordering <T>(this IQueryable <T> queryable, OrderingQuery <T> orderingQuery)
{
if (orderingQuery == null)
{
return(queryable);
}
var first = true;
// Loop through the order column to build the expression tree
foreach (var column in orderingQuery.Columns)
{
// Get the property from the T, based on the key
var lambda = column.Key;
// Based on the order direction, get the right method
string method;
if (first)
{
method = column.Value == OrderDirection.Ascending ? "OrderBy" : "OrderByDescending";
first = false;
}
else
{
method = column.Value == OrderDirection.Ascending ? "ThenBy" : "ThenByDescending";
}
// itemType is the type of the TModel
// exp.Body.Type is the type of the property.
Type[] types = { typeof(T), lambda.ReturnType };
// Build the call expression
var methodCallExpression = Expression.Call(typeof(Queryable), method, types,
queryable.Expression, lambda);
// Now you can run the expression against the collection
queryable = queryable.Provider.CreateQuery <T>(methodCallExpression);
}
return(queryable);
}
