Type Alias

MDQuerySortComparatorFunction

Callback function used to sort the results of a query.

Declaration

Parameters

query

The query instance.

attrs1

A C array of attribute values for a result. The values occur in the array in the same order and position that the attribute names were passed in the sortingAttrs array when the query was created. The values of the attributes will be NULL if the attribute doesn't exist for a result or if read access to that attribute is not allowed.

attrs2

A C array of attribute values for a result. The values occur in the array in the same order and position that the attribute names were passed in the sortingAttrs array when the query was created. The values of the attributes will be NULL if the attribute doesn't exist for a result or if read access to that attribute is not allowed.

context

The user-defined context parameter provided in the function MDQuerySetSortComparator.

Return Value

The function must return one of the CFComparisonResults kCFCompareLessThan, kCFCompareEqualTo, or kCFCompareGreaterThan. There is no provision for unordered results. The comparison should be a total order relation and produce the same results for the same inputs.

See Also

Callbacks

typealias MDQueryCreateResultFunction

Callback function used to create the result objects stored and returned by a query.

typealias MDQueryCreateValueFunction

Callback function used to create the value objects stored and returned by a query.