Undo in PHP CRUD application

Question

What would be the best way to achieve an undo function in a PHP CRUD application? The only solution I've been able to come up with is using a sort of buffer table in my database that is periodically wiped.

If the user clicks the "Undo" button after deleting a record for example, the id of the last change will be passed to a handler which will pull the buffer record and reinstate it into the main table for that data type. If the "Undo" is not done in say, 4 or 5 minutes, a reaper script will drop the entry.

Does this sound feasible? Is there a better way of accomplishing this?

Answer 1

You could use a flag field in your database to mark a row for delete.

And you can setup task (crontab in linux) to delete all rows with delete flag set to true and time difference > to 5 mins.

Answer 2

I've learned to not delete anything, but simply do as Ignacio Ocampo stated by using a flag column in your DB such as status. By default set the status column to open. If your client clicks your delete button, just update that records status column to void, or deleted..

In doing this, you'll need to update your data request to pull only those records with the status column set to open. This allows the data to not be lost, but also not seen.

all undo(s) or redo(s) if applicable can reset the open status to - or + 1 record sorted by a timestamp column.

If db space is at a premium, and you need to remove old data then crontab does work, but I prefer the simplicity phpmyadmin conjob to loop a file that will wipe all void or deleted records older than time()-'(last cron run).

Answer 3

Depending on what and how you're building, you might also want to consider using one of the following solutions.

1) A pure PHP CRUD solution would be something along the lines you've mentioned, with also possibly storing cookies on the client side to track which actions are being done. Every action a new cookie is created, then your application will only have to sort the cookies by date and time. You could also set the cookies to be automatically expire after x amount of time. (Although I would expire after a x amount of steps, instead of time)

2) If you are able to use HTML5 local storage (http://www.w3schools.com/html/html5_webstorage.asp) along with some Javascript would be perfect for this, since you wouldn't have to wait around for the server to respond everytime 'undo' is clicked since all the processing would be handled locally.