Dbarone.Net.Csv 2.0.0

Dbarone.Net.Csv

Dbarone.Net.Csv is a simple CSV library that provides a CsvReader and CsvWriter class to read and write csv files. The parsing of csv is compliant to https://www.rfc-editor.org/rfc/rfc4180, and a full suite of unit tests is provided to validate the code.

CsvReader

The CsvReader class provides a single Read() method to read csv files from any Stream object. The Read() method returns a sequence of IDictionary<string, object> objects

    var input = @"field_name1,field_name2,field_name3
    aaa,bbb,ccc
    zzz,yyy,xxx";

    byte[] byteArray = System.Text.Encoding.UTF8.GetBytes(input);
    MemoryStream stream = new MemoryStream(byteArray);
    CsvReader csv = new CsvReader(stream);
    var results = csv.Read();

The Read() method will yield records. Note that if you want to read the entire csv file into memory, you will need to make a call such as ToList().

Configuration

By default, the CsvReader and CsvWriter class use the following defaults:

However, these settings can be configured in the CsvConfiguration object which is passed in the constructor to the CsvReader or CsvWriter. The following configuration is available:

CsvWriter

Csv files can be created using the CsvWriter class. The Write() method will write a sequence of IDictionary<string, object> objects to a stream.

    IEnumerable<Dictionary<string, object>> data = new IEnumerable<Dictionary<string, object>>();
    Dictionary<string, object> dict = new Dictionary<string, object>();
    dict.Add("foo", "123");
    dict.Add("bar", "456");
    dict.Add("baz", "789");
    data.Add(dict);

    MemoryStream ms = new MemoryStream();
    CsvWriter csv = new CsvWriter(ms, configuration);
    csv.Write(data);

Reading Csv Files to Strong-Typed objects

This library deals purely with parsing of CSV files. Csv files by nature are only text, and have no built-in information about types. This is why the Read() method returns a sequence of IDictionary<string, object> objects. By default, it does not make any assumptions about the type of data being read and returns all values as string values. If you need to cast or manipuate values, you can do this by implementing a RowProcess callback function on the CsvReader class.

    // This callback function converts the 1st column to an integer
    ProcessRowDelegate mapColumn = (int record, string[] headers, ref object[]? values) =>
    {
        int newValue = int.Parse((string)values![0]);
        values[0] = newValue;
        return true;
    };

    CsvReader csv = new CsvReader(stream, new CsvConfiguration { ProcessRowHandler = mapColumn });

To map records to classes, you can use the Dbarone.Net.Mapper library in conjunction with this library.

The API reference documentation can be found here: Dbarone.Net.Csv.html.

--- d.barone 3-Mar-2024 ---