Ejemplo n.º 1
0
        /// <summary>
        /// Filters a sequence of <see cref="IGeoCode"/> items based on a specified <see cref="GeoCodeRange"/>.
        /// Useful for database queries for better performance.
        /// </summary>
        public static IQueryable <T> WhereInGeoCodeRange <T>(
            this IQueryable <T> query,
            GeoCodeRange geoCodeRange)
            where T : IGeoCode
        {
            if (query == null)
            {
                throw new ArgumentNullException(nameof(query));
            }
            if (geoCodeRange == null)
            {
                throw new ArgumentNullException(nameof(geoCodeRange));
            }

            // The logic for bounding coordinates is different depending on whether geoCodeRange includes the 180th meridian.
            Expression <Func <IGeoCode, bool> > geoCodeRangePredicate = geoCodeRange.IncludesMeridian180()
                ? (Expression <Func <IGeoCode, bool> >)(x =>
                                                        (x.LatitudeGeoCode >= geoCodeRange.MinimumLatitude && x.LatitudeGeoCode <= geoCodeRange.MaximumLatitude) &&
                                                        (x.LongitudeGeoCode >= geoCodeRange.MinimumLongitude || x.LongitudeGeoCode <= geoCodeRange.MaximumLongitude)
                                                        )
                : x =>
                                                                        (x.LatitudeGeoCode >= geoCodeRange.MinimumLatitude && x.LatitudeGeoCode <= geoCodeRange.MaximumLatitude) &&
                                                                        (x.LongitudeGeoCode >= geoCodeRange.MinimumLongitude && x.LongitudeGeoCode <= geoCodeRange.MaximumLongitude);

            return(((IQueryable <IGeoCode>)query)
                   .Where(geoCodeRangePredicate)
                   .Cast <T>());
        }
Ejemplo n.º 2
0
        /// <summary>
        /// Returns true if the <see cref="GeoCodeRange"/> spans the 180th meridian.
        /// </summary>
        public static bool IncludesMeridian180(this GeoCodeRange geoCodeRange)
        {
            if (geoCodeRange == null)
            {
                throw new ArgumentNullException(nameof(geoCodeRange));
            }

            return(geoCodeRange.MinimumLongitude > geoCodeRange.MaximumLongitude);
        }