Question 192068 in PHP Question posted in
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In PHP, how do I let other methods in my class know when an exception was thrown from within another method?

I have a method that translates HTML into another language. Inside that method is a try, catch block that handles network errors. I have another method that returns true if an error occurred. And another that displays the error message.

However, I have not found a way to let either method know when the translation fails.

Here’s the method that handles the actual translation (It is part of a trait called Translate). $status is an array that is a variable in the class TranslateContent that uses this trait.

  protected function translateHTML(object $translator, string $content, string $target_language, array $status):string {
    
    if($target_language == 'en'){
      
      return $content;
    
    } 
        
    if($content):
        
        try{

          $content_translated = $translator->translateText($content, 'en', $target_language, 
              ['tag_handling' => 'html'], 
              ['formality', 'prefer_less'],
              ['split_sentences', 0]
            );

          return $content_translated;

        } catch(Exception $error){

          $status['status'] = true;
          $status['message'] = $error->getMessage();

          return $content;
        }

    endif;

    return $content;

  }

At the top of the class called TranslateContent that uses trait Translate, I declare $status:

 protected $status = [
      'error' => false,
      'message' => ''
    ];

Then here is the method that uses the translateHTML() method where the exception is thrown. The last argument I’ve added is the status array created above. (Note: I am passing an incorrect target language here to trigger the exception.)

public function translatePostContent(string $content):string {

        $post_language = $this->getPostLanguage($this->post_id);
        
        $target_language = $post_language['deepl_language_code'];

        return $this->translateHTML($this->translator, $content, 'doesnt-exist', $this->status );

    }

And lastly that methods that return the status:


public function hasError():bool{

      return $this->status['error'];

      
    }

public function getErrorMessage():string{
      
      return $this->status['message'];

    }

My thinking was, if an exception is thrown during the translation attempt, I need to update the state of $status from the within the catch block. But the $status is not being updated. Instead the code where TranslateContent is instantiated runs as if there was no error at all.

I thought this was a scoping issue initially but from what I’ve read, catch blocks do not have scoping in PHP.

What am I missing?

Tags:

2

Answers


  1. 0

    it looks like what you want is to pass "by reference" the $status variable.

    You can do so by redefining your translateHTML signature prefixing with & your $status variable:

      protected function translateHTML(object $translator, string $content, string $target_language, array &$status):string {

    That way when you "edit" the variable you will be editing the actual variable passed to the method (and not a copy, which is the default).

    The above should work, but maybe you might want to move the $status property to the trait itself. That way you can access it by using $this->status and you won’t need to pass it at all.

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  2. 0

    You declare $status like this:

    protected $status = [
      'error' => false,
      'message' => ''
    ];

    but your catch block makes two mistakes:

        $status['status'] = true;
    $status['message'] = $error->getMessage();

    You should be updating $this->status, and you should be setting $this->status['error'], like this:

        $this->status['error'] = true;
    $this->status['message'] = $error->getMessage();

    Then your call to translateHTML() has no need to pass in the $status variable.

    return $this->translateHTML($this->translator, $content, 'doesnt-exist');

    Your methods to retrieve the error status and message are correctly accessing the class property, so they should now work.

    There’s no need to pass $status by reference, or at all. That’s what class properties are for.

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