Auto Post Back

srussells

I am an asp.net developer trying to get more familiar with php. How do you auto post back in php. I have a drop down filled with users when a user is selected I want to populate some text boxes. This is really easy to do in asp by just setting the drop down autopostback property to true. Any help would be appreciated.

walterquez

Sorry, I am not sure I understood. You have a select box, and a text box. And when you select an option from the select box, it populates the text box?

I am not sure how an autopostback set to true would do anything, based on what I understood from you.

srussells

maybe i didnt do a good job of explaining. When I select something from the drop down list I want to fill the text boxes with the info that corresponds but I do not know how to accomplish this. In asp.net there is an event that would be called on post back and that is where you would populate your fields. How do I accomplish this in php?

coldwerturkey

you'll need javascript to accomplish that that.

srussells

Can you be a little more specific? Could you show me a code snippet?

Weedpacket

Well, you could look at those big JavaScript libraries that ASP.NET links into the pages.

farius

As I have always understood it that doing callbacks (auto-postbacks) with PHP requires AJAX in sorts, or just javascript.

The reason for this is that PHP is server-side where as Javascript is client side. This means that a user will call a .php page and the server will execute the code on the server and then returns the results to the browser. Where as Javascript executes the code on a 'by call' basis. So if you have a button on the page and you use the html

<button onClick="javascriptButtonFunction()" > when the user clicks the button this would send a request for the code that is within the "javascriptButtonFunction()" function and it does what ever without a page refresh (unless there is one with the code).

You can harness the two so that javascript calls a php script and the php executes and returns back to the client without a refresh, or in other words a callback.

To learn more do some google searches for AJAX. It can be confusing, but it is very powerful!!

I hope this clears things up.

djjjozsi

Here is a good example how to make dropdown, and you can change
the second and third textfield in locale.php to use another textfields, or forms.

http://phpcode.hu/url/show.php?id=6