Modifying shortcode replacements via event handler? #67

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1. mpdude commented on Apr 25, 2018

   

   mpdude

   on Apr 25, 2018

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   I may be headed in the wrong direction, but I think this would be straightforward if the ReplacedShortcode contained in the ReplaceShortcodesEvent were not read-only, so that I could just tweak the replacement strings...
2. thunderer commented on Apr 25, 2018

   

   thunderer

   on Apr 25, 2018

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   Yes, this is one of the use cases for Events::REPLACE_SHORTCODES. Here is a quick example I wrote for you, I hope I understood your problem correctly:

   • create handlers with default handler that just returns the name and content,
   • create REPLACE_SHORTCODES event handler with our replacement mechanism (copied directly from Processor),
   • this mechanism wraps each shortcode replacement in a different HTML tag (see the rewrite method),
   • creates processor with our event handler inside,
   • asserts that the code works as expected at the bottom.

   $handlers = new HandlerContainer();
   $handlers->setDefault(function(ShortcodeInterface $s) { return $s->getName().$s->getContent(); });
   
   $events = new EventContainer();
   $events->addListener(Events::REPLACE_SHORTCODES, new class {
       public function __invoke(ReplaceShortcodesEvent $event)
       {
           $text = $event->getText();
           /** @var ReplacedShortcode $s */
           foreach(array_reverse($event->getReplacements()) as $s) {
               $offset = $s->getOffset();
               $length = mb_strlen($s->getText(), 'utf-8');
               $textLength = mb_strlen($text, 'utf-8');
               $prefix = mb_substr($text, 0, $offset, 'utf-8');
               $postfix = mb_substr($text, $offset + $length, $textLength, 'utf-8');
   
               $text = $prefix.$this->rewrite($s).$postfix;
           }
   
           $event->setResult($text);
       }
   
       private function rewrite(ReplacedShortcode $r)
       {
           return [
               'what' => function(ReplacedShortcode $r) { return '<p>'.$r->getReplacement().'</p>'; },
               'goes' => function(ReplacedShortcode $r) { return '<b>'.$r->getReplacement().'</b>'; },
               'around' => function(ReplacedShortcode $r) { return '<u>'.$r->getReplacement().'</u>'; },
           ][$r->getName()]($r);
       }
   });
   
   $processor = new Processor(new RegularParser(), $handlers);
   $processor = $processor->withEventContainer($events);
   
   $text = 'a [what] [goes /] [around /] [/what] z';
   $expected = 'a <p>what <b>goes</b> <u>around</u> </p> z';
   assert($expected === $processor->process($text));
3. thunderer commented on Apr 25, 2018

   

   thunderer

   on Apr 25, 2018

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   BTW The idea of an event before Events::REPLACE_SHORTCODES which allows you to tweak the replacement seems like a good idea. It may be a quite significant performance hit, but as an optional mechanism (no handler === no hit) should work quite well. The event handler would receive ReplacedShortcode and return the new replacement which would take place of the old one. The temporary name I came up with is Events::REWRITE_REPLACEMENT I need to investigate this further, thanks!
4. thunderer

   self-assigned this

   on Apr 25, 2018
5. thunderer

   added

   issue

   on Apr 25, 2018
6. mpdude commented on Apr 26, 2018

   

   mpdude

   on Apr 26, 2018

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   Tomasz,

   thanks a lot for your quick reply and the code example above. Indeed, I've seen something similar at #40 (comment) ;-).

   I wonder if it really has to be as complicated as this, since there is already code to do this heavy lifting of merging the original content and the replacements together. I mean, if the ReplacedShortcode would allow to modify the replacement string, wouldn't we be done?

   Yes, I do know about the advantages of immutable objects... 😀