Edit dynamic records at runtime

Question

I have an ASP.NET application editing files uploaded on the server at runtime.

I have to handle CSV files so I chose the FileHelpers library.

As I don't know what will be the headers of the CSV, I use this library to create a custom class dynamically at runtime and fill a DataTable with the headers and records.

Then, the application adds a new column to the DataTable and the values generated for each row.

I need the new values to be written in the CSV file so I need to edit the records at runtime without knowing the class format.

Here is the snippet of what I have done so far, but if you could give me an hint on how to perform this, I will really appreciate :)

List<object> values = new List<object>();

var classBuilder = new DelimitedClassBuilder("CSVClass", delimiter.ToString(), dataTable);

classBuilder.LastField.FieldOptional = true;

Engine = new FileHelperEngine(classBuilder.CreateRecordClass());

string lastFieldName = classBuilder.LastField.FieldName;
i = 0;
foreach (dynamic record in Engine.ReadFile(filePath))
{
    record.Test = newValues[i]; //This line is working as the new column is named "Test" but if the column name changes, it throws an exception of course

    values.Add(record);

    i++;
}

Engine.WriteFile(filePath, values);

Answer 1

I finally found my way through this.

The solution was to use the CsvEngine class and his DataTableToCsv method.

For the curious ones, here is the final code:

List values = new List();

string header = null;

DataRow row = dataTable.NewRow();

int i = 0;
foreach (var value in newValues)
{
    string newValue = value;

    if (i == 0)
    {

        List<object> headers = valuesDictionnary[0].ToList<Object>();
        int count = 1;
        while (true)

            if (headers.Contains(newValue))
            {
                newValue = value + "_" + count;
                count++;
            }
            else
                break;

        header = newValue;
        dataTable.Columns.Add(newValue);

        foreach(DataColumn column in dataTable.Columns)
        {
            row[column.ColumnName] = column.ColumnName;
        }

        dataTable.Rows.InsertAt(row, 0);
    }

    dataTable.Rows[i][header] = newValue;
    i++;
}

CsvEngine.DataTableToCsv(dataTable, filePath, new CsvOptions("CSVOptions", delimiter, filePath));

dataTable.Rows.RemoveAt(0);