private string BuildOrderBy(TypeMap type, object sortOrders)
{
// coalesce the dictionary
IDictionary <string, SortOrder> sortOrderDict = type.CoalesceSortOrderDictionary(sortOrders);
// validate / return
StringBuilder orderBySb = new StringBuilder("ORDER BY ");
for (int i = 0; i < sortOrderDict.Count; i++)
{
string propertyName = sortOrderDict.Keys.ElementAt(i);
SortOrder order = sortOrderDict[propertyName];
if (type.AllProperties.TryGetValue(propertyName, out PropertyMap pm) == false)
{
throw new ArgumentException($"Failed to find property {propertyName} on {type.Type.Name}");
}
orderBySb.Append($"{pm.Column} {this.GetSortOrder(order)}");
if (i != sortOrderDict.Count - 1)
{
orderBySb.Append(", ");
}
}
return(orderBySb.ToString());
}
/// <inheritdoc />
public Task <PagedList <T> > ReadList <T>(object whereConditions, object sortOrders, int pageSize, int pageNumber)
{
TypeMap type = TypeMap.GetTypeMap <T>();
// create the paging variables
int firstRow = ((pageNumber - 1) * pageSize) + 1;
int lastRow = firstRow + (pageSize - 1);
// get the candidate objects
IEnumerable <T> filteredT;
IDictionary <string, object> whereDict = type.CoalesceToDictionary(whereConditions);
if (whereDict.Count == 0)
{
filteredT = this.ReadAll <T>().GetAwaiter().GetResult();
}
else
{
filteredT = this.ReadList <T>(whereConditions).GetAwaiter().GetResult();
}
// get the total number of candidate objects
int total = filteredT.Count();
// validate / build the ordering string
string ordering = string.Empty;
IDictionary <string, SortOrder> sortOrderDict = type.CoalesceSortOrderDictionary(sortOrders);
for (int i = 0; i < sortOrderDict.Count; i++)
{
// check whether this property exists for the type
string propertyName = sortOrderDict.Keys.ElementAt(i);
if (!type.AllProperties.ContainsKey(propertyName))
{
throw new ArgumentException($"Failed to find property {propertyName} on {type.Type.Name}");
}
ordering += string.Format(
"{0}{1}{2}",
propertyName,
sortOrderDict[propertyName] == SortOrder.Descending ? " desc" : string.Empty,
i != sortOrderDict.Count - 1 ? "," : string.Empty);
}
// order the rows and take the results for this page
filteredT = filteredT.AsQueryable <T>().OrderBy(ordering).Skip(firstRow - 1).Take(pageSize);
return(Task.FromResult(new PagedList <T>()
{
Rows = filteredT,
HasNext = lastRow < total,
HasPrevious = firstRow > 1,
TotalPages = (total / pageSize) + ((total % pageSize) > 0 ? 1 : 0),
TotalRows = total
}));
}
