How to delete data? - Similar to msg you get when closing an unsaved/unsent email msg

ChetUbetcha

I'm trying to do something similar to when you are in an email program and you are composing a msg, then click on a link or back button and get a warning to either save or lose your email msg data.

I have people creating reports which creates an ID. Then they add all the lines of the report. How do I warn them if they go away from a page without submitting the report, all the data will be deleted? This is due to the fact I have a numbering system in place that needs to go in sequential order. So if they go away from the page without submitting, there is an ID in limbo that never gets used and hte next submitted report gets the NEXT number. Looks like one is skipped.

etully

First of all, it's very important that you NOT rely on your ID #'s being nice an sequential. Someday one will get corrupted or it will be a duplicate or whatever and you will have to delete it and there will be a hole. It's very important that you design your web site to handle ID #'s not being sequential.

Either (A) create the record when they load the page and have an ID# that may or may not actually get used, or (😎 give them a page where they can create all the lines of the report but don't actually create the record (and commit an ID# to this report) until they submit the page. Either way is perfectly fine. If you try to create a web site that relies on perfection where nothing ever goes wrong (the kinds of things that end up causing a skip in sequential ID#'s), then your web site is just a big house of cards waiting to collapse.

As for the technical question, have a javascript variable that keeps a record of whether or not the page has been saved. (This is called recording state). The variable might be called "page_has_been_edited" or something like that. When the page first loads, the variable should be set to zero.

Whenever anyone adds a line or makes a change of any kind, then set the variable to "1". Whenever anyone clicks save and the save was successful, then set it to "0".

Then use a javascript body on_unload event to call a function that checks to see if "page_has_been_edited". If the variable is equal to 1, then alert that they should save the page.