[Resolved] Help for a newbie

Bah__Name

I've exhausted my books at home. Can anyone help?

I have a drop down list box of options on my web page, but when I click it, nothing happens.

if (!isset($_POST[UserOption])) {
 $_SESSION['UOption']="fbOption_1.jpg";
}else{
 $_SESSION['UOption']=$_POST[UserOption];
}
print "</TD><TD><H3>Select an option</H3>";
print "<form action='$_SERVER[PHP_SELF]' method='POST'>";
print "<SELECT NAME='UserOption'>";
print "<OPTION VALUE='fbOption_1.jpg'>Option 1";
print "<OPTION VALUE='fbOption_2.jpg'>Option 2";
print "<OPTION VALUE='fbOption_3.jpg'>Option 3";
print "<OPTION VALUE='fbOption_4.jpg'>Option 4";
print "<OPTION VALUE='fbOption_5.jpg'>Option 5";
print "<OPTION VALUE='fbOption_6.jpg'>Option 6";
print "<OPTION VALUE='fbOption_7.jpg'>Option 7";
print "<OPTION VALUE='fbOption_8.jpg'>Option 8";
print "<OPTION VALUE='fbOption_9.jpg'>Option 9";
print "<OPTION VALUE='fbOption_10.jpg'>Option 10";
print "<OPTION VALUE='fbOption_11.jpg'>Option 11";
print "<OPTION VALUE='fbOption_12.jpg'>Option 12";
print "</form>";
print "</TD></TR></TABLE>";
print "<BR><BR><BR>";

I want $POST[UserOption] to be set to whatever choice is clicked in the drop down box, so when the page is refreshed, this value is copied to $SESSION['UOption'].

Also, while I'm at it, can I refresh the page (or send the selected option to th e $_POST variable) when the drop box option is clicked?

juschillinnow

you can only reset the value if you submit your form. The reason for this is because php is handled server side. Clicking stuff on the page is client side. So while their clicking away, the server is twiddling it's thumbs.

You need to use something like javascript for this.

What you can do is:

Whenever the user changes an option, the form will be submitted.

You will have to write a short script at the top of your page that handles this submit, and reset's you session variables.

juschillinnow

Also, I'll save you alot of time while you're still a newbie.....

It's not good practice to have php parse all your html..

You should break out of php whenever possible like:

<?
if (!isset($_POST[UserOption])) { 
 $_SESSION['UOption']="fbOption_1.jpg"; 
}else{ 
 $_SESSION['UOption']=$_POST[UserOption]; 
}
?> 
</TD><TD><H3>Select an option</H3> 
<form action='$_SERVER[PHP_SELF]' method='POST'> 
<SELECT NAME='UserOption'> 
<OPTION VALUE='fbOption_1.jpg'>Option 1 
<OPTION VALUE='fbOption_2.jpg'>Option 2 
<OPTION VALUE='fbOption_3.jpg'>Option 3 
<OPTION VALUE='fbOption_4.jpg'>Option 4 
<OPTION VALUE='fbOption_5.jpg'>Option 5 
<?
echo "something else";
?>

Sometimes it is necessary to have php parse html or sometimes more convenient.....so in my opinion try and use ECHO instead of PRINT, like:

<?
$string = "hello";
echo $string." Howdy partner ".$string;
echo "$string Howdy partner $string";
?>

Those both produce the same results.

Bah__Name

But I get these irritating headers already sent info if I have any HTML. Eg, the page loads ok, I click a link to somewhere else, but when I hit backspace to return to the original page I get the 'headers already sent' message, then if I hit refresh, it loads okay 😕

Thanks by the way 😉

juschillinnow

ah, Is your code short enough to post?

It's probably coming from where you set your original sessions.

you need to have those in an

if(!isset(the set here))
{

}

Bah__Name

Sorry, you've lost me??

<?php
session_start();
$_SESSION['Value'] = 'ThisValue'; 
//$_SESSION['Value'] = 'ThatValue'; 
print "<html>";
print "<head>";

etc..
then later

print "<A HREF=

etc

juschillinnow

<?
if(!isset($SESSION['Value']))
{
session_start();
$SESSION['Value'] = 'ThisValue';
}
?>
<?
rest of code
?>

Try that and see what happens. Make sure that is at the extreme top of your file, with no comments or blank lines before it.

Bah__Name

Is the session_start() line the cause of the 'headers sent' problem? 'Cause I could do this for every page.

juschillinnow

not sure. The headers already sent means that your server is trying to write more headers, but html has already been started to be printed to the page, so the header process dies with an error.

Sessions could be a possible cause of this, I guess.

Weedpacket

Originally posted by Bah! Name
But I get these irritating headers already sent info if I have any HTML. Eg, the page loads ok, I click a link to somewhere else, but when I hit backspace to return to the original page I get the 'headers already sent' message, then if I hit refresh, it loads okay 😕

Here's a couple of suggestions:
Look at the line number where the error is reported. This is the line which is trying to send the header.
Look at the line number where it says output has been started. This is the line where output was generated.

juschillinnow's comment about breaking out of PHP to do blocks of HTML is still valid and has no bearing on when output or headers are sent or not sent.

echo "plain HTML";
echo "more plain HTML";

print "plain HTML";
print "more plain HTML";

are exactly the same as

?>
plain HTML
more plain HTML
<?php

except that the last one is quite a bit faster and a lot less ugly.

Weedpacket

Originally posted by juschillinnow

<?
if(!isset($_SESSION['Value']))
{
session_start(); 
$_SESSION['Value'] = 'ThisValue';
}
?>
<?
rest of code
?>

[/b]

The problem with this code is that it tries to look at the value of a session variable, and only starts the session if the session variable is not already set (which, of course, it won't be, because the session hasn't been started).

juschillinnow

Originally posted by Weedpacket
The problem with this code is that it tries to look at the value of a session variable, and only starts the session if the session variable is not already set (which, of course, it won't be, because the session hasn't been started).

Right. Thanks. You da man.

And in my opinion, echo is still a much better choice than print.

Not for html, but if you have to mix html and php together. It make life alot easier.

Bah__Name

It has sorted the problem. I have all new ones now 😃
But thats another thread
btw, whats the difference between echo and print?

juschillinnow

none except if you want to echo or print string values. Take the following:

$string = "hello all";

echo "$string ! Supprise";

printf("%s ! Supprise", $string);

So that does not look that complicated. But if you have many values you need to print or echo, print can get pretty confusing, escpecially if you have to go back and change values at some point.

Weedpacket

Originally posted by Bah! Name
It has sorted the problem. I have all new ones now 😃
But thats another thread
btw, whats the difference between echo and print?

There's a whole thread on this subject in the Echo Lounge, in which the options are voted on by a bunch of people with nothing better to do with their time 🙂

juschillinnow

com'n weedpacket. just trying to help a newbie out.

For the record: The echo and print had nothing at all to do with the original post. I was merely making a suggestion.

Anywayzzzz.. I got to get back to work 🙂

Weedpacket

Originally posted by juschillinnow
com'n weedpacket. just trying to help a newbie out.

Hence the 🙂; but the fact the thread exists suggests something...