Simple flow control question

mikejarrett

I am wanting to do something that seems very simple, yet I can't figure it out.

How do I pass control from one php module to another? I know how to call functions and that is not what I want.

What I find I do currently a lot is:
<?php

//... php code to do something in a database...

echo 'processing completed successfully<br>';

echo '<a href="mainmenu.php">Continue</a>';

Rather than send control back for an confirmation, I just want to run my mainmenu.php module. I tried

header ("Location:mainmenu.php");

But I get an error message about having sent headers. Any help is greatly appreciated.

intenz

How about...

include_once( 'mainmenu.php' );

rehfeld

you cannot send headers after you have output anything to the browser. that means no echos, and none of this either

<html>
<?php 
header();
?>

even a single space or new line is considered output.

you can use output buffering to let you output headers after sending output though( look into ob_start() ), but its kinda useless if your redirecting because then theres no point to sending anything but a redirection header in the first place, because they wont ever see anything you echo at them anyway.

an alternatice to redirecting them could be just run the next part of your code in the same script, for example using include()

mikejarrett

Thanks for the input, and it seems like include_once might be the way to go.

However, I am a little concerned (and maybe this is lack of my understanding of the architecture), if I include_once a module that is called repeated, won't the session chew up a bunch of memory and potentially run out?

For example

mainmenu.php
<?php
echo '<form action="DoSomething.php">';
echo '<input type="submit">'
?>

DoSomething.php
<?php
echo 'Hello<br>';
include_once ('mainmenu.php');
?>

Is php smart enough not to make another copy of mainmenu.php (I guess maybe that's the 'once') or if you go through this loop a bunch of times, are you using up resource?

Thanks again for your help.

mikejarrett

As I think about it, is this a better approach?

mainmenu.php

<?php
Function DoSomethingFunction
{
include_once ( 'DoSomething.php');
}
if ($_POST['CallProc']== "DoIt")
{
$retval = DoSometingFunction;
}

echo '<form action="mainmenu.php" method="post">';
echo '<input type="hidden" value="DoIt" name="CallProc">';
echo '<input type="submit"></form>'
?>

DoSomething.php
<?php
echo 'Hello<br>';
?>

This seems like to more correct way to do it, but seems a little funky for reading and it might get a little difficult when code gets long and complex (though, of course, complex is bad).

Comments?

Roger_Ramjet

Nope, that is why it is include_ONCE.

It can get confusing when you fragment your code and including the same functions twice really would not work. So the facility to only load a file if it is not already loaded really keeps things tight for us.