JSP Session Variables

Note that the codes in this blog post have not been tested. I will update this post once I have tried implementing them.

Session Variables
Session variables are useful for associating data with your visitor. The variables will disappear once the session expires. Here is what you need:
1) A HTML Form to retrieve data from the visitor

<FORM METHOD=POST ACTION="savedata.jsp"> What's your name? <INPUT TYPE=TEXT NAME=username SIZE=20> <INPUT TYPE=SUBMIT>

2) savedata.jsp – This is the target page of the form, and this page manipulates the data.

<% String name = request.getParameter( "username" ); session.setAttribute( "theName", name ); %> <HTML> <BODY> Hello, <%= session.getAttribute( "theName" ) %> </BODY> </HTML>

First, you retrieve the value of the parameter "username" that was posted using the form; then you set the attribute "theName" with the value that was retrieved. To retrieve the session value, use the getAttribute(..) function and pass in the attribute name.

Source: http://www.jsptut.com/Sessions.jsp.

Pop-up window upon submitting PHP Form

Context:
Suppose you have a form with 2 different buttons :
1) "Save Post" - on click, processes the data in the form, refreshes the current page (but displays an empty form).
2) "View All Posts" - on click, processes the data in the form, opens a pop-up window, gathers information based on the posted form data from the main window.Currently we are concerned with button (2).

PHP Code:
<form name="mainForm" action="" method="post">
<input name="email">
<input type="password" name="password">
<input name="mypost">
<input type="submit" name="button1" value="Save Post">
<button type="button" onClick="return viewTempAds()">View All</button>
</form>

Javascript Code:
function viewAllPosts() {
document.forms['mainForm'].action="viewAllPosts.php";
document.forms['mainForm'].target="popup";
document.forms['mainForm'].onSubmit="window.open('','popup','menubar=no,width=600')";
document.forms['mainForm'].submit();
}

Explanation:
Both buttons 1 and 2 require the form to carry out different actions after submitting. As such, we can dynamically change the value of the form action by using Javascript. We set the value of the action value to the desired page that we wish to display in the pop-up, and we set the form value of onSubmit to open a new window. We are also submitting the form remotely in the Javascript function.