public void GetExpressionTest()
{
IQueryable<TestEntity> source = Entities.AsQueryable();
//空条件
Expression<Func<TestEntity, bool>> predicate = FilterHelper.GetExpression<TestEntity>();
Assert.True(source.Where(predicate).SequenceEqual(source));
//单条件，属性不存在
FilterRule rule = new FilterRule("Name1", "5", FilterOperate.EndsWith);
FilterRule rule1 = rule;
Assert.Throws<OSharpException>(() => FilterHelper.GetExpression<TestEntity>(rule1));
//单条件
rule = new FilterRule("Name", "5", FilterOperate.EndsWith);
predicate = FilterHelper.GetExpression<TestEntity>(rule);
Assert.True(source.Where(predicate).SequenceEqual(source.Where(m => m.Name.EndsWith("5"))));
//二级条件
rule = new FilterRule("Name.Length", 5, FilterOperate.Greater);
predicate = FilterHelper.GetExpression<TestEntity>(rule);
Assert.True(source.Where(predicate).SequenceEqual(source.Where(m => m.Name.Length > 5)));
//多条件，异常
Assert.Throws<OSharpException>(() => new FilterGroup
{
Rules = new List<FilterRule> { rule, new FilterRule("IsDeleted", true) },
Operate = FilterOperate.Equal
});
//多条件
FilterGroup group = new FilterGroup
{
Rules = new List<FilterRule> { rule, new FilterRule("IsDeleted", true) },
Operate = FilterOperate.And
};
predicate = FilterHelper.GetExpression<TestEntity>(group);
Assert.True(source.Where(predicate).SequenceEqual(source.Where(m => m.Name.Length > 5 && m.IsDeleted)));
//条件组嵌套
DateTime dt = DateTime.Now;
group = new FilterGroup
{
Rules = new List<FilterRule>
{
new FilterRule("AddDate", dt, FilterOperate.Greater)
},
Groups = new List<FilterGroup> { group },
Operate = FilterOperate.Or
};
predicate = FilterHelper.GetExpression<TestEntity>(group);
Assert.True(source.Where(predicate).SequenceEqual(source.Where(m => m.AddDate > dt || m.Name.Length > 5 && m.IsDeleted)));
}
private static LambdaExpression GetPropertyLambdaExpression(ParameterExpression param, FilterRule rule)
{
string[] propertyNames = rule.Field.Split('.');
Expression propertyAccess = param;
Type type = param.Type;
foreach (string propertyName in propertyNames)
{
PropertyInfo property = type.GetProperty(propertyName);
if (property == null)
{
throw new OSharpException(string.Format(Resources.Filter_RuleFieldInTypeNotFound, rule.Field, type.FullName));
}
type = property.PropertyType;
propertyAccess = Expression.MakeMemberAccess(propertyAccess, property);
}
return(Expression.Lambda(propertyAccess, param));
}