PHP trying to understand how to generate thumbnail from directory - php

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.