Question

I’m wondering if it’s normal. I add an option to a select with jQuery. When I save with an asp button, I don’t see the changes on the server side in the click event.

And the HTML is all correct after I add the option.

Is it a coding problem or I don’t understand something? 😛

$(selectCourant)
             .append($("<option></option>")
             .attr("value",$(dropdown).val())
             .text($(dropdown + " option:selected").text())); 

Thank you

ASP.NET And vb.net

Answer 1

Yes you did not understand something.

What’s happens on client web browser side is not inform the server – except if you make extra code and do that programmatically.

Server side did not know, nether read the dom (html struct) and even if he wish to do it, he can not read it.

A solution is to send it back with a post value. For example, when you add an option, also add an other value to a hidden input and post back your action to the server side. Then you are responsibly to read this values, understand them and update your data on code behind.

Code behind not only do not know whats happens on client, but also do not know what’s the same do, after the page have been send and come back with a post back, and here comes the viewstate. Codebehind saves most of informations on viewstate (except if you disable it on controls, or on pages) to remember that changes. Then on post back the viewstate send to code behind, and code behind decode it and knows what have done before the post back.

To say few words more.
When you prepare and “render” the html page, you send all html struct to the browser client , and browser render the page. When browser make a post back to the server sends only whats on the post back variables so the server knows only that informations that come back and use this informations to replay with a new html struct.