The User Experience that a library provides must be at least equal with is quality and speed. And frankly, CSVtoLINQ rocks on latest two, as I presented in previous articles Import CSV file and query it with LINQ and continuing in LINQ wonder world, but lacks a little on the User Experience(in our case Developer Experience)  by not having some events of starting, progress and ending of the parsing.

Especially important, while parsing huge files, is a confirmation for the user that something happens and (ideally) the point in which the processing is. That is why, thanks to Matt Perdeck for sharing the entire source of the library, I was able to improve it by adding events.

So, let’s see some code!

Modifications into LINQtoCSV library – CSVContext.cs

Important: All modifications will be made in the CsvContext class from LINQtoCSV namespace – the CSVContext.cs file.

First we’ll add the ReadStarted event to the library – it will fire when the reading of the CSV file has started.

// defining the delegate
public delegate void ReadStartedHandler(object sender, EventArgs e);
// here we define the event
public event ReadStartedHandler ReadStarted;

// the call of the event processing
protected virtual void OnReadStarted() {
  if (ReadStarted != null) {
    // we use empty eventargs because nothing is needed on readstarted event, just the confirmation of parsing started
    ReadStarted(this, EventArgs.Empty);
  }
}

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