Strange behavior

[Nick Belane]

Hi everybody!

The following code is an include in different templates and works fine:
 

<?php if ($page->id != 1) { ?>
<div class="container">
	<div class="breadcrumbs hidden-xs hidden-sm" role="navigation" aria-label="<?= __('Sie sind hier'); ?>:">
		<span class="blue"><?= __('Sie sind hier'); ?>:</span>
		<?php
			foreach($page->parents() as $item) {
				echo "<span><a href='$item->url'>$item->title</a></span>"; 
			}
			echo "<span>$page->title</span>"; 
		?>
	</div>
</div>
<?php } ?>

 

But if I remove the first if-statement "$page->id != 1" it throws an error:
"Uncaught Error: Call to undefined function __()"

Probably it has to do with the foreach loop.
I am not the best in PHP

Thanks in advance

 

[abdus]

Assuming you're on >PW v3.0 It's most likely a namespace issue. Before if statement open a new PHP tag (<?php ?>) and specify namespace like so

<?php namespace ProcessWire; ?>
<?php if ( /* ... */) { ?>

 

[Nick Belane]

Ah, thank you. Now it works.
But I don't get it. I thought the namespace must defined on the top of the page. Just one time.
I have set this in the header include.

Do I have to set the namespace in every include?

[abdus]

It needs to be set on every template file.

Although there's template compiler that does it for you, I am not satisfied with how it performs.

Here's the relevant blog post:

https://processwire.com/blog/posts/processwire-3.0.14-updates-file-compiler-fields-and-more/#file-compiler-updates

[Nick Belane]

"I am not satisfied with how it performs. "

Why?

[DaveP]

@abdus is absolutely right. Just to expand a little, what is happening when you do that is saying to PHP 'in this file the variable "item" to be treated as "ProcessWire\item" (for example)'. That means that if you were to find some code on e.g. GitHub that you wanted to include(), so long as it is namespaced, it can use an "item" variable (which will be treated as e.g. "ClassName\item") and can't conflict with your "item" variable.

I'm currently developing a personal site that uses an image processing library I found on GitHub and it was fairly straightforward (even to a thickhead like me), to sort out the namespacing stuff, thus ensuring no naming conflicts.

FWIW I thought namespacing was an unnecessary faff when Ryan first started on PW 3.n, but having seen the benefits, and considering the only downside is one extra line of PHP at the top of every file, it's not really worth leaving it out.

[Nick Belane]

Thank you DaveP! 
This was really the first good explanation for the namespace-stuff for me as a newbie...

Great community here!

[DaveP]

Just trying to save you the head scratching I had to go through to get even that kind of rudimentary understanding!