XEROF

Build 4.9.0.21 of xlsgen is a fix pack related to importing data from CSV, JSON, HTML and XML files.

the behavior of the automatic type inference is improved. It tries to find patterns when numbers are associated to a string inside a cell, but it does not do so anymore at the expense of growing too much the dictionary of number formats and styles. In other words, it does well, wherever applicable. This is a welcome improvement since this automatic type inference was introduced more than a year ago (in xlsgen 4.5, actually).
autofitting columns is now performed automatically right after the import phase, so the imported data looks cleaner in Excel.
autofitting columns was already performed silently for JSON, HTML and XML data streams. It was not performed for CSV data at all.
an auto-fit property is introduced in all 4 data import options (i.e. for CSV, JSON, HTML and XML). This property lets an application control whether or not auto-fit is wanted. For instance, in case auto-fit is not wanted, just pass FALSE to the boolean :

worksheet.Import.CSV.Options.AutoFit = FALSE