Saving data from meta box checkboxes generated in a loop - php

Question

I'm trying to save data from dynamically generated checkboxes in Wordpress meta boxes. For now it almost works - but as you can see each checkbox has the same name and ID which is being used later on, so it cannot be like that.
This is how I create checkboxes:
<?php
$args = array( 'post_type' => 'teachers');
$loop = new WP_Query( $args );
while ( $loop->have_posts() ) : $loop->the_post();
?>
<label for="meta-checkbox-two">
<input type="checkbox" name="meta-checkbox-two" id="meta-checkbox-two" value="yes" <?php if ( isset ( $prfx_stored_meta['meta-checkbox-two'] ) ) checked( $prfx_stored_meta['meta-checkbox-two'][0], 'yes' ); ?> />
<?php the_title() ?>
</label>
<?php endwhile; ?>
And here's saving:
// Checks for input and saves
if( isset( $_POST[ 'meta-checkbox-two' ] ) ) {
update_post_meta( $post_id, 'meta-checkbox-two', 'yes' );
} else {
update_post_meta( $post_id, 'meta-checkbox-two', '' );
}
As I said it almost works - it saves everything called "meta-checkbox-two" - meaning everything, which is not the goal.
This is where I'm getting lost. I'm trying to make each name and ID end with the post ID that the loop is retrieving. Here's how the code looks then:
Generating checkboxes:
<?php
$args = array( 'post_type' => 'teachers');
$loop = new WP_Query( $args );
while ( $loop->have_posts() ) : $loop->the_post();
?>
<label for="meta-checkbox-two">
<input type="checkbox" name="meta-checkbox-<?php the_ID() ?>" id="meta-checkbox-<?php the_ID() ?>" value="yes" <?php if ( isset ( $prfx_stored_meta['meta-checkbox-' . the_ID()] ) ) checked( $prfx_stored_meta['meta-checkbox-'] . the_ID(), 'yes' ); ?> />
<?php the_title() ?>
</label>
<?php endwhile; ?>
Saving them:
$args = array( 'post_type' => 'teachers');
$loop = new WP_Query( $args );
while ( $loop->have_posts() ) : $loop->the_post();
// Checks for input and saves
if( isset( $_POST[ 'meta-checkbox-'.the_ID()] ) ) {
update_post_meta( $post_id, 'meta-checkbox-'.the_ID(), 'yes' );
} else {
update_post_meta( $post_id, 'meta-checkbox-'.the_ID(), '' );
}
endwhile;
But in the second case the data is not saved. What am I doing wrong?

Answer 1

Just try code below - not tested but should work - I just changed input name on array as you can see name="meta-checkbox-two[]" and that is the point also did unique input id like you did.
<?php
$args = array( 'post_type' => 'teachers');
$loop = new WP_Query( $args );
while ( $loop->have_posts() ) : $loop->the_post();
?>
<label for="meta-checkbox-two">
<input type="checkbox" name="meta-checkbox-two[]" id="meta-checkbox-two-<?php the_ID() ?>" value="yes" <?php if ( isset ( $prfx_stored_meta['meta-checkbox-two'] ) ) checked( $prfx_stored_meta['meta-checkbox-two'][0], 'yes' ); ?> />
<?php the_title() ?>
</label>
<?php
endwhile;
?>