PHP trying to understand how to generate thumbnail from directory

Question

This is currently what I have. When I include it in my index.php and then call the function on pageload, I get a blank page. So something is wrong here, but I don't know what. I feel like I'm really close though. I just want to create thumbnails of images in a directory, and then show them in HTML as a list of images you can click that trigger lightboxes.

I'm still really shaky in PHP. I'm trying to wrap my head around editing images in a directory.

<?php
function buildThumbGallery(){

    $h = opendir('/Recent_Additions/'); //Open the current directory
    while (false !== ($curDir = readdir($h))) {
        if (!file_exists('/Recent_Additions/thumbs/')) {
            $thumbDir = mkdir('/Recent_Additions/thumbs/', 0777, true);
        }else{
            $thumbDir = '/Recent_Additions/thumbs/';
        }
        $width = 200;
        $height = 200;
        foreach ($curDir as $image) {
            $filePath = $curDir."/".$image;
            $genThumbImg = $image->scaleImage($width, $height, true);
            $newThumb = imagejpeg($genThumbImg, $thumbDir, 100);

            echo '<li> <a class="fancybox" data-fancybox-group="'.basename($curDir).'" href="'.$filePath.'" title="'.basename($curDir)." ".strpbrk(basename($filePath, ".jpg"), '-').'"><img src="'.$newThumb.'"/>'.basename($curDir).'</a>';
            imagedestroy($newThumb);
        }echo '</li>';
}
?>

Answer 1

You are doing several things wrong:

• You're not closing the while loop.
• Readdir already loops through a directory, your foreach is not doing anything.
• You are missing quotes in your echo.
• You are calling the method scaleImage on a string, I think you meant to call the function imagescale.

You're missing and misunderstanding a lot of stuff, take a look at how to create a thumbnail here: https://stackoverflow.com/a/11376379/4193448 Also see if you can enable PHP errors, getting a blank page while your code is full of errors is not really helping is it?

Answer 2

::EDIT::

With help from @swordbeta, I got my script working properly. Here is the code for future reference:

<?php
function buildThumbGallery(){

    $curDir = "./Recent_Additions/";
    $thumbsPath = $curDir."thumbs/";

    if (!file_exists($thumbsPath)) {
        mkdir($thumbsPath, 0777, true);
    }
    foreach(scandir($curDir) as $image){
        if ($image === '.' || $image === '..' || $image === 'thumbs') continue;
        if(!file_exists($thumbsPath.basename($image, ".jpg")."_thumb.jpg")){
            // Max vert or horiz resolution
            $maxsize=200;

            // create new Imagick object
            $thumb = new Imagick($curDir.$image);  //'input_image_filename_and_location'

            $thumb->setImageFormat('jpg'); 

            // Resizes to whichever is larger, width or height
            if($thumb->getImageHeight() <= $thumb->getImageWidth()){
            // Resize image using the lanczos resampling algorithm based on width
                $thumb->resizeImage($maxsize,0,Imagick::FILTER_LANCZOS,1);
            }else{
                // Resize image using the lanczos resampling algorithm based on height
                $thumb->resizeImage(0,$maxsize,Imagick::FILTER_LANCZOS,1);
            }

            // Set to use jpeg compression
            $thumb->setImageCompression(Imagick::COMPRESSION_JPEG);
            $thumb->setImageCompressionQuality(100);
            // Strip out unneeded meta data
            $thumb->stripImage();
            // Writes resultant image to output directory
            $thumb->writeImage($thumbsPath.basename($image, ".jpg")."_thumb.jpg");  //'output_image_filename_and_location'
            // Destroys Imagick object, freeing allocated resources in the process
            $thumb->destroy();
        }else{
            echo '<a class="fancybox" data-fancybox-group="'.basename($curDir).'" href="'.$curDir.basename($image, "_thumb.jpg").'" title="Recent Addition - '.basename($image, ".jpg").'"><img src="'.$thumbsPath.basename($image, ".jpg")."_thumb.jpg".'"/></a>';
            echo '<figcaption>'.basename($image, ".jpg").'</figcaption>' . "<br/>";   
        }
    } 
}
?>

::Original Post::

Ok, after going back and doing some more research and suggestions from @swordbeta, i've got something that works. My only issue now is I can't get the images to show in my index.php. I'll style the output in CSS later, right now I just want to see the thumbnails, and then later build them into lightbox href links:

<?php
function buildThumbGallery(){

    $curDir = "./Recent_Additions/";
    $thumbsPath = $curDir."/thumbs/";

    if (!file_exists($thumbsPath)) {
        mkdir($thumbsPath, 0777, true);
    }

    $width = 200;

    foreach(scandir($curDir) as $image){
        if ($image === '.' || $image === '..') continue;
        if(file_exists($thumbsPath.basename($image)."_thumb.jpg")){
            continue;
        }else{
            // Max vert or horiz resolution
            $maxsize=200;

            // create new Imagick object
            $thumb = new Imagick($curDir.$image);  //'input_image_filename_and_location'

            // Resizes to whichever is larger, width or height
            if($thumb->getImageHeight() <= $thumb->getImageWidth()){
            // Resize image using the lanczos resampling algorithm based on width
                $thumb->resizeImage($maxsize,0,Imagick::FILTER_LANCZOS,1);
            }else{
                // Resize image using the lanczos resampling algorithm based on height
                $thumb->resizeImage(0,$maxsize,Imagick::FILTER_LANCZOS,1);
            }

            // Set to use jpeg compression
            $thumb->setImageCompression(Imagick::COMPRESSION_JPEG);
            $thumb->setImageCompressionQuality(100);
            // Strip out unneeded meta data
            $thumb->stripImage();
            // Writes resultant image to output directory
            $thumb->writeImage($thumbsPath.basename($image)."_thumb.jpg");  //'output_image_filename_and_location'
            // Destroys Imagick object, freeing allocated resources in the process
            $thumb->destroy();
        }
    }   echo '<img src="'.$thumbsPath.basename($image)."_thumb.jpg".'" />' . "<br/>";
}
?>

At the moment, the output from the echo isn't showing anything, but the rest of the script is working properly (i.e. generating thumbnail images in a thumbs directory).

I'm guessing i'm not formatting my echo properly. This script is called in my index.php as <?php buildThumbGallery(); ?> inside a styled <div> tag.