PHP Function "opendir()" in Wordpress. Works in one file, but not in other

Question

Alright, this will need a long explanation. Sorry if it's too long:

/////////////// INTRODUCTION ///////////////

There doesn't seem to be much information around about using opendir() within Wordpress and the way it should be implemented. However, after a couple hours of research, trial and error, I got it working on a custom page template.

I need it to fetch game thumbnail images from folders and output them as a grid, divided by categories (each folder is a category).

/////////////// MY APPROACH ///////////////

I created a function in functions.php that opens and reads a folder using the following relative path:

"wp-content/games/".$category."/"

Where $category is the argument of the function (defined by the user).

This is how my function looks like now:

function fetch_game_images($category){
    //$category = 'featured';
    $imageFiles = array();
    $extensions = array('.JPG','.PNG');
    $directory = "wp-content/games/".$category."/"; 
    $openDir = opendir($directory);

    while ($imgFile = readdir($openDir))
        {
        if ($imgFile <> '.' and $imgFile <> '..')
            {
            $extension = strtoupper(substr($imgFile, strrpos($imgFile, '.')));
            if (in_array($extension, $extensions))
                {
                $imageFiles[] = $imgFile;
                }
            }
        }

    closedir($openDir);

    foreach ($imageFiles as $k => $v)
    {
        $withoutExt = preg_replace("/\\.[^.\\s]{3,4}$/", "", $v);
        $hyphenlessName = str_replace("-"," ",$withoutExt);
        $formattedName = strlen($hyphenlessName) > 24 ? substr($hyphenlessName,0,24)."..." : $hyphenlessName;

        if ($category == 'featured'){
        if (strpos($formattedName,'netent') !== false) {$finalName = trim($formattedName, 'netent');}
        else if (strpos($formattedName,'mg') !== false) {$finalName = trim($formattedName, 'mg');}
        else { $finalName = $formattedName;}
        }
        else { $finalName = $formattedName;}

        echo '<div class="games-list-item"><div class="game-container">';
        echo '<a href=""><img src="'.get_bloginfo('url').'/'.$directory.'/'.$v.'" alt=""/>';
        echo '<h3>'.$finalName.'</h3></a>';
        echo '<div class="game-hover">';
        echo '<img src="'.get_bloginfo('url').'/'.$directory.'/'.$v.'" alt=""/>';
        echo '<div class="game-buttons-holder"><a class="play_now_btns" href="">Play Now</a><a class="free_play_btns" href="">Free Play</a></div></div><!--.game-hover-->';
        echo '</div><!--.game-container--></div><!--.games-list-item-->';
    }
}

/////////////// MY APPROACH RESULTS ///////////////

When I load the Wordpress Page using the Page Template that calls this function, it loads the images flawlessly.

But then, I have to change the games category dynamically using jQuery, I take the category/folder name, save it in a JavaScript variable and send it to a php that grabs it and passes it to the fetch_game_images(); function.

My jQuery GET looks like this:

    $('#sidebar-list-menu li a').live('click', function(){
        event.preventDefault();
        var category = $(this).data('category');
        //alert(cat);
            //$('div.games-grid').html('<span class="loadingNotification">LOADING</span>');
            $.get("<?php bloginfo('template_directory'); ?>/games-list-loader.php?category="+category,
                    function(data){
                    //alert(data);
                    //$('span.loadingNotification').remove();
                    $('div.games-grid').html(data); 
                }); 

    });

And the PHP File (located in the same theme directory) looks like this:

<?php $parse_uri = explode( 'wp-content', $_SERVER['SCRIPT_FILENAME'] );
require_once( $parse_uri[0] . 'wp-load.php' );


                $cat = $_REQUEST['category'];
                fetch_game_images($cat);


?>
                    <div class="clear"></div>

/////////////// THE ISSUE ///////////////

The issue is that when I click on the sidebar link that triggers the GET call and tries to fetch the data from the PHP, it outputs the following error:

Warning: opendir(wp-content/games/featured/) [function.opendir]: failed to open dir: No such file or directory in [...]

Which shouldn't happen at all, since both my Page Template and my custom PHP file are in the same directory and load Wordpress core to use functions.php.

/////////////// THE QUESTION ///////////////

Does anybody know what could be the reason behind this behaviour? I read most of the google results I could find about this opendir() error, but most of them seem to point at a wrong path, but mine seem to be correct.

Others say that it might be a permissions issue. But I got my folders set to 755 and the files to 644.

So, any help would be great! Thank you.

<======== /////////// EDIT ///////// =========>

Thanks to the help by @CBroe, I figured it out:

Instead of using a loose path like

"wp-content/games/".$category."/"

I changed it to a server-relative one

ABSPATH . "/wp-content/games/".$category."/"

And then I just changed the output to match the changes:

echo '<img src="'.get_bloginfo('url').'/wp-content/games/'.$category.'/'.$v.'" alt=""/>';

This works from both locations and solved the GET issue.

Answer 1

Most likely your relative path is not the correct one – usually happens when scripts are run from two different physical locations.

Making a debug output of getcwd() directly before calling opendir will show you what directory the scripts are actually running in in both cases – and that location is the one used to “complete” the relative path, so if those don’t match it’s only natural one of them will fail.

Relative paths are always tricky that way. It’s usually preferable to use a path relative to the server root (starting with a /) to avoid such issues.