How to "globalize" PHP variables? - php

Question

I have a page named ChangeApprovalInfo.php - It has a function called Row_Rendered as follows;
function Row_Rendered() {
// To view properties of field class, use:
//var_dump($this-><FieldName>);
$RecordOwner = $this->RequestUser->CurrentValue;
echo $RecordOwner;
}
Echoing $RecordOwner gets me the data I will need for a sql query on another page....
I have another page called ChangeApprovalEdit.php - This page has
<?php include_once "ChangeApprovalinfo.php" ?>
at the top of the file.
ChangeApprovalEdit.php has a function where I need the $RecordOwner variable as defined in ChangedApprovalInfo.php
If I add "echo $RecordOwner" on the ChangeApprovalEdit.php page, I get an error saying it's an unknown variable. My understanding is that I need to "make it global" or some such business. I know very little about PHP and the pages I am editing are long and complex. (to me, at least)
What do I need to do? I know that the information I have provided might not be enough to answer the question. I don't know enough to even know exactly what I need to ask. If more information is needed, I will edit and follow up.
pastebin of the files
ChangeApprovalInfo.php = http://pastebin.com/bSRM1wwN
ChangeApprovalEdit.php = http://pastebin.com/AStG9pqb
EDIT:
Changing Row_Rendered to this seems to be more effective. I'm having trouble seeing WHERE I can later echo this variable... but I'm getting somewhere with this...
function Row_Rendered() {
// To view properties of field class, use:
//var_dump($this-><FieldName>);
$GLOBALS['RecordOwner'] = $this->RequestUser->CurrentValue;
}

Answer 1

Don't echo variables from functions, which just outputs them to the standard output. return them from the function so you can use the value elsewhere as well.
function Row_Rendered() {
$RecordOwner = $this->RequestUser->CurrentValue;
return $RecordOwner;
}
Then instead of
$obj->Row_Rendered();
use
echo $obj->Row_Rendered();
and if you want to use the value elsewhere, use
$value = $obj->Row_Rendered();

Answer 2

You can do a couple of things:
First, you can return $RecordOwner from the function, and store its value in a variable. This method is usually preferred.
function Row_Rendered() {
// To view properties of field class, use:
//var_dump($this-><FieldName>);
$RecordOwner = $this->RequestUser->CurrentValue;
echo $RecordOwner;
return $RecordOwner;
}
// Store it in a variable when calling the function.
$RecordOwner = Row_Rendered();
Or, you can make it global inside the function:
function Row_Rendered() {
// To view properties of field class, use:
//var_dump($this-><FieldName>);
$GLOBALS['RecordOwner'] = $this->RequestUser->CurrentValue;
echo $GLOBALS['RecordOwner'];
}

Answer 3

You can use the $GLOBALS superglobals array, like this:
function Row_Rendered() {
$GLOBALS['RecordOwner'] = $this->RequestUser->CurrentValue;
}
However, you should not do that. Instead, refactor your application so that the view in ChangeApprovalinfo.php just contains a function, which is then called with the appropriate parameters.

Answer 4

EDIT: Chaning Row_Rendered to this seems to be more effective. I'm having trouble seeing WHERE I can later echo this variable... but I'm getting somewhere with this...
function Row_Rendered() {
// To view properties of field class, use:
//var_dump($this-><FieldName>);
$GLOBALS['RecordOwner'] = $this->RequestUser->CurrentValue;
}
I feel compelled to write another answer to this update. Let me demonstrate the use of globals as seen from outside that function:
$obj->Row_Rendered();
$obj->foobar();
echo $GLOBALS['RecordOwner'];
Quick, what will be echoed and where does that value come from? Well, it depends on what $obj-foobar() does. Maybe it changes the global variable. Maybe it doesn't. Who knows if the variable has been set at all? How would you trace back what happened exactly without adding a debug line after every single function call?
And that's just three lines of code. Imagine that in an application of any complexity.
Now, the same thing if I return the value from Row_Rendered:
$owner = $obj->Row_Rendered();
$obj->foobar();
echo $owner;
If the Row_Rendered method is behaving as it should (returning the owner), this code is very predictable. If you do not follow this pattern, you'll have a hell of a time getting anything done when the application grows to any halfway complex size.

Answer 5

Set the variable as global from within the function
$my_global_var = "old value";
function doing_stuff(){
global $my_global_var; //this will use the global variable instead of creating a local one
$my_global_var = "new value";
}
echo $my_global_var;//returns "new value"