How does Google Docs make full folder upload possible? What technology are they using?
The benefit of full folder upload is that the folder structure is preserved meaning that folders within folders will also upload and become collections within collections.
Folder upload is made possible by two ways one by support of chrome and in other browsers since they do not support folder upload we use applet .Applet provide UI for folder upload and
Applet writes folder path etc.. to variables such as $_POST,$_File etc.. .Using these variables we create directory structure same as that of orginal selected folder and files are written to their corresponding folder.
