Techniques and Web Technologies
Demo is based on REDIPS.drag JavaScript library with enabled shift drop option. After element is dropped to the cell, other elements will be shifted to make room. Animation is optional and can be turned off. The presented demo can be a good start point for various sorting Web applications.
This post shows how to shift table content using JavaScript. REDIPS.shift library contains four methods to shift table content in any direction (up, right, down and left). By default, content bunching is disabled.
Date shift in JavaScript can be done by counting days of the month and thinking of 28 or 29 days in February. Don’t forget the year. This is a long and complicated algorithm. I suggest a simpler solution. Transform date to the number of milliseconds, and make easy arithmetic with integers. After addition and subtraction, create date from the milliseconds.