String Replace that contains hashtags-php-CodePudding

I have a string like this

$content="#Love #Lovestories #Lovewalapyar";

Want to make these hashtags clickable.

I have an array.

$tags=
(
    [0] => stdClass Object
        (
            [TOPIC_ID] => 132
            [TOPIC_NAME] => Love
            [TOPIC_URL] => http://local/topic/132/love            
        )

    [1] => stdClass Object
        (
            [TOPIC_ID] => 3347
            [TOPIC_NAME] => LoveStories
            [TOPIC_URL] => http://local/topic/3347/lovestories            
        )

  
    [2] => stdClass Object
        (
            [TOPIC_ID] => 43447
            [TOPIC_NAME] => lovewalapyar
            [TOPIC_URL] => http://local/topic/43447/lovewalapyar            
        )

);

Using this to make hashtags clickable.

foreach($tags as $tag){
    $content=str_ireplace('#'.$tag->TOPIC_NAME, '<a href="'.$tag->TOPIC_URL.'" title="'.htmlentities($tag->TOPIC_NAME).'">#'.$tag->TOPIC_NAME.'</a>', $content);
}

Getting this: It replaces only love not the other string.

Trying to replace/Make these hashtags clickable.

Any help would be much appriciated.

CodePudding user response：

The reason is simple. You have hashtags which are substrings of other hashtags. To avoid this overlapping issue, you can sort your array in a non-increasing fashion replacing longer strings first and shorter strings later, completely avoid the overlapping issue, like below:

<?php

usort($tags,function($a,$b){
   return strlen($b->TOPIC_NAME) <=> strlen($a->TOPIC_NAME);
});

Update:

Your hashtag text inside <a></a> is causing the str_ireplace to reconsider it. For this you need to pass the array values and their respective replacements in an array, or, instead of adding a #, you can use a HTML character entity # which will be ignored by str_ireplace() and would work properly, like below:

'<a ...>&#35;'.$tag->TOPIC_NAME.'</a>';

Updated Snippet:

<?php

usort($tags,function($a,$b){
   return strlen($b->TOPIC_NAME) <=> strlen($a->TOPIC_NAME);
});

foreach($tags as $tag){
    $content = str_ireplace('#'.$tag->TOPIC_NAME, '<a href="'.$tag->TOPIC_URL.'" title="'.htmlentities($tag->TOPIC_NAME).'">&#35;'. $tag->TOPIC_NAME.'</a>', $content);
}

CodePudding user response：

I would use the regular expression /#(\w*)/ (hashtag and whitespace) and preg_replace() to replace all occurrences.

Something like this:

$content = "#Love #Lovestories #Lovewalapyar";
$pattern = '/#(\w*)/';
$replacement = '<a href="#$1">$1</a>';
preg_replace($pattern, $replacement, $content);

this will give you:

<a href="#Love">Love</a> 
<a href="#Lovestories">Lovestories</a> 
<a href="#Lovewalapyar">Lovewalapyar</a>

You can test that regex online here.

If you need some advanced logic as Magnus Eriksson mentioned in comments you can use preg_match_all and iterate over your found matches.

Something like this:

$content = "#Love #Lovestories #Lovewalapyar";
$pattern = '/#(\w*)/';
preg_match_all($pattern, $content, $matches);
foreach ($matches[1] as $key => $match) {
    // do whatever you need here, you might want to use $tag = $tags[$key];
}