Question

I’d like to make this function more generic by specifying the property of Foo that I search on in the function arguments. At the moment I have to have a function for every property of Foo rather than just one generic function.

private Func<Foo, bool> ByName(bool _exclude, string[] _searchTerms)
{
    if (_exclude)
    {
        return x => !_searchTerms.Contains( x.Name.Replace(" ", "").ToLower() );
    }

    return x => _searchTerms.Contains( x.Name.Replace(" ", "").ToLower() );
}

Is it possible to make this function more generic to be able to pass the search property of Foo?

Answer 1

You can easily add a Func<Foo, string>:

private Func<Foo, bool> By(Func<Foo, string> property,
                           bool exclude, string[] searchTerms)
{
    if (exclude)
    {
        return x => !searchTerms.Contains( property(x).Replace(" ", "").ToLower() );
    }

    return x => searchTerms.Contains( property(x).Replace(" ", "").ToLower() );
}

You would call it like that:

By(x => x.Name, ...);

Please note that this method is not generic. It only supports properties of type string, because your search method uses Replace on the property and your searchTerms are also strings.

BTW: Please note the way I named the parameters. The .NET naming convention doesn’t use underscores for parameters.