Aggregating HTML files

Question

I am using PHP to keep my webpage organized.

The directory looks like this:

root/folder/file1
root/folder/file2
root/folder/file3
root/index.php

Each file is very simple html doc with content containing a title tag, which I use to create a nav bar.

I want index.php to aggregate all the content from file1, file2 and file3, in addition to creating a nav bar up at the top.

The code I have achieves this successfully, but I'm not sure if I'm doing this in a practical way.

$domain = "domain/"
$dir = "folder/";
$files = scandir($dir);

// loop over all the files, saving their contents and ids to arrays
$contents = Array();
$titles = Array();
$ids = Array();
for ($x = 0; $x < sizeof($files); $x++) {   
  if ($files[$x] != "." && $files[$x] != "..") {
    $filename = $domain . $dir . $files[$x];
    $file = fopen($filename, "r");
    $data = file_get_contents($filename);
    array_push($contents, $data);

    $regex = '#<title>(.*?)<\/title>#';  
    preg_match($regex, $data, $match);
    $title = $match[1];
    array_push($titles, $title);

    $regex2 = '#( |-|,)#';
    $id = preg_split($regex2, $title)[0];   
    array_push($ids, $id);
  }
}

// the first loop sets the nav bar
echo "<div id='navigation'>";
echo "<ul>";
for ($x = 0; $x < sizeof($contents); $x++) {
    echo "<li><a href='#" . $ids[$x] . "'>" . $titles[$x] . "</a></li>";    
}
echo "</ul>";
echo "</div>";

// this second loop sets the contents
echo "<div id='content'>";
for ($x = 0; $x < sizeof($contents); $x++) {
    echo "<div id='" . $ids[$x] . "'>" . $contents[$x] . "</div>";    
}
echo "</div>";

I like the idea of having all the content on one big page and the nav bar helps a lot when I'm viewing it on my phone.

Questions

1. Are there any obvious problems with the way I am aggregating my files?
2. Are there challenges I may encounter that I have not yet experienced?
3. Is there a generally accepted way of doing this while achieving the same result?

Answer 1

Basically you need to remove the unused fopen() call and change ponderous operators to handy ones as for some reason you made a peculiar choice in favor of the former, like for vs. foreach, array_push vs simple assignment, etc. Also consider a cleaner way to output HTML

<?php
$pattern = "domain/folder/*.*";
$files = glob($pattern);

// loop over all the files, saving their contents and ids to arrays

$contents = [];
$titles = [];
$ids = [];
foreach ($files as $filename)
{
    $data = file_get_contents($filename);
    $contents[] = $data;

    preg_match('#<title>(.*?)<\/title>#', $data, $match);
    $titles[] = $match[1];

    $ids[] = preg_split('#( |-|,)#', $match[1])[0];
}
?>
<div id='navigation'>
<ul>
<?php foreach ($titles as $x => $title): ?>
    <li><a href="#<?=$ids[$x]?>"><?=$title?></a></li>
<?php endforeach ?>
</ul>
</div>

<div id='content'>
<?foreach ($contents as $x => $content): ?>
    <div id="<?=$ids[$x]?>"><?=$content?></div>
<?php endforeach ?>
</div>