Question

I am creating an API and I want to expose an interface called IReportFields, I want the client to implement this class and basically get fields from whatever datasource (usually database).

Within my IReport interface I want to take in an instance of the IReportFields (could be more than one, in my app I have at least 4), then do whatever I need to do within that interface, usually it will be something like build report or whatever.

So for example:

public interface IReportField
{
 ICollection<ReportField> GetFields();
}

There could be various type of report fields e.g. they could derive for 3 or 4 different database tables etc…

Then on my main interface I will:

public interface IReport
{
 string GetReport(IReportField[] field);
}

Question:

IReportFields can have multiple implementations, i.e. many different types of fields, how do I call the method GetReport keeping in mind I am using Ninject, how do I wire my interfaces together?

//this bit is where I am stuck, how do I pass in the params as I dont want a hard dependancy on a class that requires me to get a report

 IFieldReport field1 = new FieldImp1();
 IFieldReport field2 = new FieldImp2();

 var report = GetReport(feild1, field2);

Answer 1

You can use Constructor injection to have all wired up IFieldReports such as you have the wiring as follows:

IKernel kernel = new StandardKernel();

kernel.Bind<IReportField>().To<FieldImp1>();
kernel.Bind<IReportField>().To<FieldImp2>();
kernel.Bind<IReport>().To<ReportImpl>();

And you have a ReportImpl like this:

public class ReportImpl : IReport
{
    public ReportImpl(List<IReportField> fieldReports)
    {
        // you now have all the wires to IReportField in fieldReports parameter
        foreach(IReportField fieldReport in fieldReports)
        {
            var fields = fieldReport.GetFields();
            // do whatever with the fields
        }
    }
}

Please let me know if I got it wrong