Reading local files on HTML5
I wanted to perform some calculations over STL files. I thought it would be nice to be able to do that within a modern browser so it would work on any computer without the need to install any binary. But I have never dealt before with reading local files using Javascript within an HTML page. I was sure it had to be a way as sites like gcode.ws or chilipeppr.com allow you to either select a local file to be analyzed or to just drag and drop it to be sent to a CNC machine. But my experience with Javascript is quite limited and I have never found myself at ease with that language (though it is mostly the mess of Javascript + HTML + server extensions + server database what makes usually programmer's life a living hell). But given it was a long time without venturing myself into the intricacies of the File API I decided I would learn a new trick. Most of the trouble is the asynchronous behavior of the system that took me a while to understand . In many languages, you open a fil