Prevent duplicate posts within foreach - php

Question

Hello all, I'm currently working on a foreach loop that pulls images from a gallery from the backend of Wordpress. The gallery is working fine and as expected, however, I would like to prevent duplicate photos from appearing.
<?php if () $query->have_posts() ):
$thumbs = [];
?>
<?php
foreach( $query->posts as $gallery ):
$images = get_field('gallery_images', $gallery->ID);
if( $images ):
foreach( $images as $image ):
$cropped_img = aq_resize( $image['url'], 1024, 576, true, true, true );
$img_id[] = $image['ID'];
$thumbs[] = $cropped_img;
?>
Unrelated HTML to the Problem
<?php endforeach; endif; endforeach; ?>
<?php foreach($thumbs as $thumbnail): ?>
<div class="gallery__thumb"><img src="<?= $thumbnail; ?>"></div>
<?php endforeach; ?>
Here is essentially what I'm trying to work out. I've thought to add two variables for the image ID so that they aren't duplicated in the first block of code. So that first if/foreach state looks like:
<?php if( $images ):
foreach( $images as $image ):
$cropped_img = aq_resize( $image['url'], 1024, 576, true, true, true );
$img_id[] = $image['ID'];
$do_not_duplicate[] = $image['ID'];
$thumbs[] = $cropped_img;
?>
Followed by the followed foreach for the thumbnails
<?php foreach($thumbs as $thumbnail): ?>
<?php foreach($img_id as $img): ?>
<?php if ($img == $do_not_duplicate) : ?>
//do nothing
<?php else : ?>
<div class="gallery__thumb"><img src="<?= $thumbnail; ?>"></div>
<?php endif; ?>
<?php endforeach; endforeach; ?>
The problem I'm experiencing with this is I'm getting 22 images outputed 23 times because there are 22 images being pulled(with 1 duplicate). Essentially I'm trying to accomplish 22 images with no duplicates.
Any insight would be greatly appreciated, thank you in advance.

Answer 1

Simply edit your php code like that:
$thumbs[$image['ID']] = $cropped_img;
It will be an associative array in which the images are stored with ids as keys, so if an doubled image is pushed to array, it will just override the old one

Answer 2

Based on your code, it should be:
<?php if( $images ):
foreach( $images as $image ):
$cropped_img = aq_resize( $image['url'], 1024, 576, true, true, true );
$img_id[] = $image['ID'];
$thumbs['url'][] = $cropped_img;
$thumbs['id'][] = $image['ID']
?>
then
<?php foreach($thumbs as $thumbnail): ?>
<?php if (!in_array($thumbnail['do_not_duplicate'], $img_id)): ?>
<div class="gallery__thumb"><img src="<?= $thumbnail['url']; ?>"></div>
<?php endif; ?>
<?php endforeach; ?>

Answer 3

You could check if the image id already exists in the $img_id array before adding it.
I modified your code below
<?php if () $query->have_posts() ):
$thumbs = [];
?>
<?php
foreach( $query->posts as $gallery ):
$images = get_field('gallery_images', $gallery->ID);
if( $images ):
// Initialize $img_id[]
$img_id = [];
foreach( $images as $image ):
// Only add to the $img_id array and $thumbs array if
// $image['ID'] is not in $img_id array
if( ! in_array($image['ID'], $img_id)):
$cropped_img = aq_resize( $image['url'], 1024, 576, true, true, true );
$img_id[] = $image['ID'];
$thumbs[] = $cropped_img;
?>
Hope this helps!
Depending on what your $image['ID'] values are, you may need to pass use the third argument of in_array() to do strict checking.
Reference: http://php.net/manual/en/function.in-array.php