Filter issue

TWD
(@twd)

6 years, 2 months ago
How can I make this code more robust?
i.e. so it doesn’t throw an error if the ICL_LANGUAGE_CODE constant doesn’t exist.
I have used this code snippet on WPML sites to attach different font-families
depending on the language class attached to the <body> tag.
```
add_filter('body_class', 'append_language_class');
function append_language_class($classes){
  $classes[] = ICL_LANGUAGE_CODE;
  return $classes;
}
```
- This topic was modified 6 years, 2 months ago by Jan Dembowski.

Viewing 7 replies - 1 through 7 (of 7 total)

mark l chaves
(@mlchaves)

6 years, 2 months ago
Hi @twd,

Give something like this a try.
```
define('ICL_LANGUAGE_CODE', 'something');

$classes[] = defined('ICL_LANGUAGE_CODE') ? ICL_LANGUAGE_CODE : false; 
var_dump($classes); // Dumps 'something'
```
```
// define('ICL_LANGUAGE_CODE', 'something');

$classes[] = defined('ICL_LANGUAGE_CODE') ? ICL_LANGUAGE_CODE : false; 
var_dump($classes); // Dumps false
```
Thread Starter TWD
(@twd)

6 years, 2 months ago
I don’t follow.

What about something simple like this?:
```
add_filter('body_class', 'append_language_class');
function append_language_class($classes){
  if(ICL_LANGUAGE_CODE){
    $classes[] = ICL_LANGUAGE_CODE;
    return $classes;
  }
}
```
mark l chaves
(@mlchaves)

6 years, 2 months ago

Hi @twd,

Your code would throw a warning or error depending on which PHP version used.

I suggest you run both my examples and your code as a proof to yourself what will work and what won’t. That’s the beauty of coding–like mathematics you can always test your answer 😉

Thanks!

P.s. Learn more about the defined function here https://www.php.net/manual/en/function.defined.php
Thread Starter TWD
(@twd)

6 years, 2 months ago
Ah thanks. I’m learning already.
Didn’t realize that there is a different way to check for the existence of variables,

isset()

compared to constants

defined()

looks like I’ve got a lot of study to do.

I’m a bit confused about “something” in your example though.
Can you flesh that out a bit?

And why do I need to write the function twice?
The two code examples are identical, no?
- This reply was modified 6 years, 2 months ago by TWD.
- This reply was modified 6 years, 2 months ago by TWD.
Moderator bcworkz
(@bcworkz)

6 years, 2 months ago

The constant definition in the second is commented out so no definition is made. Thus the output is different.

Do you know about the ternary operator? boolean ? 'something' : 'another';
It’s equivalent to if ( boolean ) 'something' else 'another'; except it returns the value where if statements do not.
Thread Starter TWD
(@twd)

6 years, 2 months ago
@bcworkz

OK. At least the second snippet makes sense now.

Why is it necessary to include this line?
var_dump($classes); // Dumps false
- This reply was modified 6 years, 2 months ago by TWD.
- This reply was modified 6 years, 2 months ago by TWD.
mark l chaves
(@mlchaves)

6 years, 2 months ago
Hi @twd,

I recommend you run the code yourself so learn what it’s doing. You can also Duck Duck Go or Google var_dump function.

https://www.php.net/manual/en/function.var-dump.php

var_dump is useful for testing and debugging! So, it’s necessary for testing and proofing.

Once you prove the code works, you can remove the var_dump call. You should really be testing all this code yourself as proof.

Thanks!
- This reply was modified 6 years, 2 months ago by mark l chaves. Reason: Clarification