public static void Configure(Action <SearchUtilitiesOptions> options)
{
_utilitiesOptions = new SearchUtilitiesOptions();
options.Invoke(_utilitiesOptions);
}
public static IQueryable <T> ApplySearch <T>(this IQueryable <T> query, ISearchOptions options)
{
if (options?.Search?.Length > 0)
{
if (_utilitiesOptions == null)
{
_utilitiesOptions = SearchUtilitiesOptions.DefaultOptions;
_comparisonExpressionProviderFactory = _utilitiesOptions.ComparisonExpressionProviderFactory;
}
var _searchQuery = options.Search;
var searchQueryLength = _searchQuery.Length;
// get given type's all properties
var properties = typeof(T).GetProperties();
var propertiesLength = properties.Length;
// iterate over all terms
for (int i = 0; i < searchQueryLength; i++)
{
if (string.IsNullOrEmpty(_searchQuery[i]))
{
continue;
}
// expression -> name eq shahid
var tokens = _searchQuery[i].Split(' ');
if (tokens.Length > 3)
{
// remove null or empty items
tokens = tokens.Where(x => !string.IsNullOrEmpty(x)).ToArray();
}
if (tokens.Length == 3)
{
string @operator = tokens[1];
string value = tokens[2];
for (int j = 0; j < propertiesLength; j++)
{
// if property has sortable attribute and sort term equals to property name
var searchableAttribute = properties[j].GetCustomAttributes <SearchableAttribute>().FirstOrDefault();
bool isSearchable = searchableAttribute != null && properties[j].Name.Equals(tokens[0], StringComparison.OrdinalIgnoreCase);
if (isSearchable)
{
// build up the LINQ expression backwards:
// query = query.Where(x => x.Property == "Value");
var parameter = ExpressionUtilities.Parameter <T>();
// x.Property
var left = parameter.GetPropertyExpression(properties[j]);
// "Value"
var constantValue = Convert.ChangeType(tokens[2], properties[j].PropertyType);
var right = Expression.Constant(constantValue);
// x.Property == "Value"
var comparisonExpressionProvider = _comparisonExpressionProviderFactory.CreateProvider(tokens[1].ToLower());
var comparisonExpression = comparisonExpressionProvider.GetExpression(left, right);
// x => x.Property == "Value"
var lambda = ExpressionUtilities
.GetLambda <T, bool>(parameter, comparisonExpression);
// query = query.Where...
query = query.DynamicWhere(lambda);
}
}
}
}
}
return(query);
}
