main.js

function showFolderInSite() {
	var done = false;

	// The while loop and try - catch statement are used to automatically retry if
	// there's an issue during the execution (common issue: SitesApp: Internal error).
	while (!done) {
		try {
			var files = DocsList.getFolderById('0B_F4bEJWqt_VRnUzRElES2JoMXM').getFiles();
			var page = SitesApp.getPageByUrl('https://sites.google.com/a/bil.omu.edu.tr/belge/a');
			var listItems = page.getListItems();

			for (i in listItems) {
				listItems[i].deleteListItem();
			}

			for (i in files) {
				var name = files[i].getName();

				// Skip certain files based on their names.
				if (/(^_|taslak|draft)/i.test(name))
					continue;

				// Title field
				var title = '<a href=\'' + files[i].getUrl() + '\'>' + name + '</a>';

				// Type field
				var type = files[i].getType();

				// condition: if the type is "blob_item" replace it with the filename extension
				if (type == "blob_item") {
					type = name.substring(name.lastIndexOf('.'));
				}

				// Size field
				// To indicate the size properly, we need multiple conditions:
				// - If size > 0, we show the size, else (if size = 0)
				//   it's a Google Drive file and we can hide this zero.
				// - Calculate the length of the number (28099 is five
				//   digits, 2158080 is seven digits):
				// If length < 7 digits then size is < 1mb.
				//   Indicate 'kb' and remove the last digits (the bytes).
				// Else,
				//   indicate 'mb' and remove the last digits (kilobytes and bytes).
				var size = files[i].getSize();

				if (size > 0) {
					var length = size.toString().length;

					if (length < 7) {
						size = size.toString().substring(0,length - 3) + 'kb';

					} else {
						size = size.toString().substring(0,length - 6) + 'mb';
					}

				} else {
					size = '';
				}

				// Owner field
				// Take the email address and remove everything after the @.
				var owner = files[i].getOwner().toString().substring(0,files[i].getOwner().toString().indexOf('@'));

				// Last Updated field
				// .formatDate() is a method from the Utilities Services
				var lastUpdated = Utilities.formatDate(files[i].getLastUpdated(), 'GMT', 'yyyy-MM-dd');

				// Add data according to the order of columns in your list
				// page.addListItem([title, owner, lastUpdated, type, size]);
				page.addListItem([title, owner, lastUpdated, type]);
			}

			done = true;
		}

		catch(e){
		}
	}
}