Wsrtjtyk

I want to implement server side filtering for two data tables having different IQueryable list

public IQueryable<ClassA> search(IQueryable<ClassA> query,string name,string number)

 {

    if (name!= null )

         query = query.Where( a =>a.name.Contains(name) );

    if (number!= null )

         query = query.Where( a =>a.number.ToString().Contains(numbr) );

    return query;

 }

and

public IQueryable<ClassB> search(IQueryable<ClassB> query,string address, string email)

 {

   if (address!= null )

         query = query.Where( a =>a.name.Contains(address) );

   if (email!= null )

         query = query.Where( a =>a.email.Contains(email) );

   return query;

 }

Since the implementation is same but ClassA and ClassB has different attributes involving different checks to search the value.

How to make a single generic function where I can perform searching with both of these classes?

Possible solution, using object reflection. Parameter has two strings in pair. First is the name of property, second is the value of it.

 public IQueryable<T> search(IQueryable<T> query, params Tuple<string, string> parameters)

 {

   Type type = typeof(T);

   PropertyInfo properties = type.GetProperties();

   foreach(var parameter in parameters)

   {

     PropertyInfo pi = properties.Where(a => a.Name == parameter.Item1).FirstOrDefault();

     if (pi != null)

     {

       query = query.Where(a => pi.GetValue(a).ToString().Contains(parameter.Item2));

     }

   }



   return query;

 }

You can make both clases of the same interface IPropertyWalker for example. It should have thestring indexer.

public string this[string key]

{

    switch(key)

    {

        case "Name"

            return Name;        

        //list all you need for your class

    }

}

And then pass property names to compare data.

Improving on @wannadreams response, you can lookup property information only if member type of the target is a property. Here is a full example.

        class ClassA

        {

            // Will work

            public string Name { get; set; }

            // Will not work

            public string Name;

        }



        public static async Task Main(string args)

        {

            IQueryable<ClassA> query = ...

            search(query, Tuple.Create(nameof(ClassA.Name), "myName"));

        }



        public static IQueryable<T> search<T>(

            IQueryable<T> query,

            params Tuple<string, string> parameters)

            where T : class

        {

            foreach(var criteria in parameters) {

                var property = typeof(T).GetProperty(criteria.Item1);

                if (property == null) continue;

                // you also need to verify the property was retrievable from the instance.

                query = query.Where(item => property.GetValue(item) != null)

                    .Where(item => property.GetValue(item).ToString().Contains(criteria.Item2));

            }



            return query;

        }