OpenCart: How to make a global variable?

Question

I am trying to make two global variables within OpenCart. I basically want to be able to declare them in any of my .tpl files

<?php echo $global1; ?>

I have tried editing, library/system.php and also config.php by adding $global1="test" inside my files. However calling that in .tpl files is not working?

Example, look at the file below, I want to be able to call these variables anytime.. do I have to edit config.php or what?? The example shows the $header call which is used on every .tpl file.

not_found.tpl

<?=$header?>
<div class="breadcrumb">
<? foreach ($breadcrumbs as $breadcrumb) { ?>
    <? $breadcrumb['separator']; ?><a href="<?=$breadcrumb['href']?>"><?=$breadcrumb['text']?></a>
<? } ?>
</div>
<div id="content">
    <?=$global1?>
    <img src="/catalog/view/theme/default/image/error.png"/>
</div>
<?=$footer?>

Updated

/catalog/controller/common/header.php

<?php   
class ControllerCommonHeader extends Controller {


    protected function index() {

        // NEW GLOBAL VARS
        $cdnDefault="//www.gorgeouscouturedev.com/catalog/view/theme/";
        $currentUseLang = $this->language->get('code'); 

And now in /catalog/view/theme/default/template/common/home.tpl

<?=$header?>
<?=$column_left?>
<?=$column_right?>
<div id="content">

<? echo $cdnDefault ?>
<? echo $currentUseLang ?>

    <?=$content_top?>
        <div class="flexslider">
            <ul class="slides">
                <li><img src="catalog/view/theme/default/image/desktop.png"/></li>
                <li><img src="catalog/view/theme/default/image/blogger.png"/></li>
            </ul>
        </div>
    <?=$content_bottom?>
</div>
<?=$footer?>

And the errors:

 Notice: Undefined variable: cdnDefault in /catalog/view/theme/default/template/common/home.tpl on line 6
 Notice: Undefined variable: currentUseLang in /catalog/view/theme/default/template/common/home.tpl on line 7 

Answer 1

If you are just wanting to use a static value, you can just use a constant. Simply create one in your config.php file(s) such as

define('CDN_URL', 'http://cdn.someurl.com/');

You can then use

<?php echo CDN_URL; ?>

anywhere in your application. If you want to code it like you have in your edited question, th fundamental flaw with your code is that you are using $cdnDefault instead of $this->data['cdnDefault'] in your controller file, causing the undefined issue. Note however that this variable is not global in the slightest, it's merely been coded as it should be

In my opinion, the right way to do this would be to create a new setting value for you to edit in SYSTEM > SETTINGS in your administration area, and then call it using $this->config->get('config_value_here') rather than take what is considered more of a quick hack method

Answer 2

you can use $GLOBALS super global array

for example declare it first in controller/common/header.php

$GLOBALS["1"] = "test";

then use it in any tpl file like

<?php echo $GLOBALS["1"]; ?>

regarding that header thing, that header and five other files are actually declared in every controller file (corresponding to every tpl file ) like this

$this->children = array(
            'common/column_left',
            'common/column_right',
            'common/content_top',
            'common/content_bottom',
            'common/footer',
            'common/header'     
        );

Answer to updated question

/catalog/controller/common/header.php

<?php   
class ControllerCommonHeader extends Controller {


    protected function index() {

        // NEW GLOBAL VARS
     $GLOBALS["cdnDefault"]="//www.gorgeouscouturedev.com/catalog/view/theme/";
     $GLOBALS["currentUseLang"] = $this->language->get('code');

And now in /catalog/view/theme/default/template/common/home.tpl

<?=$header?>
<?=$column_left?>
<?=$column_right?>
<div id="content">

<? echo $GLOBALS["cdnDefault"]; ?>
<? echo $GLOBALS["currentUseLang"]; ?>

    <?=$content_top?>
        <div class="flexslider">
            <ul class="slides">
                <li><img src="catalog/view/theme/default/image/desktop.png"/></li>
                <li><img src="catalog/view/theme/default/image/blogger.png"/></li>
            </ul>
        </div>
    <?=$content_bottom?>
</div>
<?=$footer?>