private static IEnumerable <T> _WeightedSearch <T>(IEnumerable <T> collection, string searchCriteria, string languageCode, bool removeItemsWithoutMatch = true)
{
#region Validations - validate parameter and collection items type
if (collection == null)
{
throw new Exception("Passed value cannot be null.");
}
if (string.IsNullOrEmpty(searchCriteria))
{
return(collection);
}
if (!typeof(T).GetProperties().Any(x => x.CustomAttributes != null && x.CustomAttributes.Any(attribute => attribute.AttributeType == typeof(SearchWeight))))
{
throw new Exception("Collection type doesn't have any property designated for search.");
}
if (!typeof(T).GetProperties().Any(x => x.CustomAttributes != null && x.CustomAttributes.Any(attribute => attribute.AttributeType == typeof(WeightedSearchValue))))
{
throw new Exception("Collection type doesn't have a property designated for search result value.");
}
#endregion Validations - validate parameter and collection items type
var propertiesForSearch = typeof(T).GetProperties().Where(x => x.CustomAttributes.Any(a => a.AttributeType == typeof(SearchWeight))).ToDictionary(x => x, x => ((SearchWeight)x.GetCustomAttributes(false).First(i => i is SearchWeight)).Weight);
var propertyWithMatchingValue = typeof(T).GetProperties().First(x => x.CustomAttributes.Any(a => a.AttributeType == typeof(WeightedSearchValue)));
var propertyWithNestedObject = typeof(T).GetProperties().FirstOrDefault(x => x.CustomAttributes.Any(a => a.AttributeType == typeof(SearchWeightNestedObject)));
var searchTokens = searchCriteria.Trim().Contains(' ') ? searchCriteria.Trim().Split(' ') : new string[1] {
searchCriteria.Trim()
};
var culture = Thread.CurrentThread.CurrentUICulture;
if (!string.IsNullOrEmpty(languageCode))
{
culture = CultureInfo.GetCultures(CultureTypes.AllCultures).FirstOrDefault(x => x.Name.EndsWith("-" + languageCode.ToUpper()));
}
foreach (var item in collection)
{
var sum = _CalculateItemMatchingValue(item, propertiesForSearch, searchTokens, culture);
// advanced - search through object tree
if (propertyWithNestedObject != null && propertyWithNestedObject.GetValue(item) != null)
{
var resultingObject = new MatchingValueObject();
_CalculateChildrenMatchingValue((IEnumerable <T>)propertyWithNestedObject.GetValue(item), searchTokens, propertiesForSearch, propertyWithNestedObject, resultingObject, culture);
sum += resultingObject.MatchingSum;
}
propertyWithMatchingValue.SetValue(item, sum);
}
if (removeItemsWithoutMatch)
{
var returnValue = collection.Where(x => (double)propertyWithMatchingValue.GetValue(x) > 0).OrderByDescending(x => (double)propertyWithMatchingValue.GetValue(x));
return(returnValue);
}
else
{
return(collection);
}
}
private static void _CalculateChildrenMatchingValue <T>(IEnumerable <T> childItems, string[] searchTokens, Dictionary <PropertyInfo, double> propertiesForSearch, PropertyInfo propertyWithNestedObject, MatchingValueObject resultObject, CultureInfo culture)
{
if (childItems != null && childItems.Any())
{
foreach (var item in childItems)
{
resultObject.MatchingSum += _CalculateItemMatchingValue(item, propertiesForSearch, searchTokens, culture);
if (propertyWithNestedObject.GetValue(item) != null)
{
_CalculateChildrenMatchingValue((IEnumerable <T>)propertyWithNestedObject.GetValue(item), searchTokens, propertiesForSearch, propertyWithNestedObject, resultObject, culture);
}
}
}
}
