Hi,
I guess the import and export functions are some of the most important functions of a CMS. And if I'm talking about an import function I'm not just meaning the functionality to import other ProcessWire backups but also to import backups from other CMS' or blogging systems like WordPress, Joomla, Drupal, Typo3, etc. I know it is a big task and of course I'm not finished it yet. I just did some researches about the different backup formats until today. And thought about the best way to create a module for this. Or some modules. So here are the two ways which I would recommend:
The one for all way:
My first idea was to find a way to convert all backups to .csv-files so the .csv-importer, written by Ryan, could import all of the different backups and you could switch more easily to ProcessWire with all of your old data. (It don't have to be the .csv-format. Another good format could be a custom .xml-format, like WordPress, but than we/I would have to write a special .xml-import-module).
The all for one way:
The other way would be to write a custom module for each different backup-file format. That would be the WordPress way (yeah, maybe you recognized already that I worked a long time with WordPress).
I myself would prefer the first way because i think it's more elegant and if every file is converted to a special Processwire backup format or maybe a standard backup format these also could be used for the backup file of your own Processwire page. But what do you think about this and how would YOU solve this problem?