FileHelpers 4.0 API brainstorming www.filehelpers.net

ProcessContext.cs

      var engine = new FileHelperEngine<RecordClass>():
      var context = engine.CreateContext(): // will return a ProcessContext<RecordClass>
      
      // e will be of type FieldErrorEventHandler<T>
      context.Callbacks.OnFieldError = e => {
            // Fields of e
              e.Field
              e.Record
              e.RecordLine
              e.ContinueAnyway
              e.FieldValue
      }:
      
      context.Callbacks.OnLineError ...
      context.Callbacks.BeforeRead
      context.Callbacks.Afterread
      context.Callbacks....
      
      engine.ReadFile("", context);
      
      // Concurrent access to this object will allow check for progress inside the context
      context.Progress.CurrentLine
      context.Progress.TotalLines
       
      context.StartTime
      context.EndTime
       
       
      

recordDescriptor.cs

// The idea is to remove RunTime Records and start using:
//    dynamic & ExpandoObject
// Provide a way to use existing type that are not decorated with attributes

// For existing types (in this cas System.Windows.Forms.Form)

var descriptor = new DelimitedRecordDescriptor<Form>("\t");

descriptor.AddField(x => x.Name)
descriptor.AddField(x => x.Width)
descriptor.AddField(x => x.Height)

var engine = descriptor.CreateEngine()

var records = engine.ReadFile("Source.txt")
//records will be a Form[]

engine.WriteFile("Destination.txt", records)


// For a dynamic types
var descriptor = new DelimitedRecordDescriptor("\t");

descriptor.AddField(x => x.Field1) // if posible or AddField("Field1")
descriptor.AddField(x => x.Field2)

var engine = descriptor.CreateEngine()

var records = engine.ReadFile("Source.txt")
//records will be a dynamic[] or ExpandoObject[]

engine.WriteFile("Destination.txt", records)



// Advance usage with fluent code
var descriptor = new DelimitedRecordDescriptor<Form>("\t");

descriptor.AddField(x => x.Name).Trim(TrimMode.Both).Align(AlignMode.Left)
descriptor.AddField(x => x.Size).ConvertToString(x => x.Width + "x" + x.Height)
                                .ConvertFromString(x => new Size(int.Parse(x.Split('x')[0]), int.Parse(x.Split('x')[1]))
descriptor.AddField(x => x.Icon).ConvertToString(x => Helper.IconToBase64(x) )
                                .ConvertFromString(x => Helper.IconFromBase64(x))

Maybe .net core support as well!? 👍

@regisbsb of course, the new feature will avoid dynamic compilation, and other permission aware problems for a simple Linq Expressions perspective 🎯

Using the field is a great idea. I make use of Linq.Expression to get the parameter info, thus the field name. Presumably though, you would add support for a naming attribute should the field name not match the header?