Admin custom checkbox array not saving to the database [closed]

Question

Using the following code for the custom checkbox to save an array of values. When the [] is left off everything works, when it's added back to save the value as an array it does not work. Any ideas...?

$posts = get_posts("post_type=test&orderby=title&order=ASC&numberposts=1000");
foreach ($posts as $postv) {
$postname = $postv->post_title;
$postslug = $postv->post_name;

<input type="checkbox" name="' . $this->prefix . $customField['name'] . '[]"
value="' . $postslug . '" ';
$sponsorselected = get_post_meta($post->ID, 'eventsponsor', $single = true);
if ((!empty($sponsorselected))&&(in_array($postslug,$sponsorselected))
{echo 'checked '; } 
echo 'style="width: auto;border:0;" />

foreach ( $this->customFields as $customField ) {
if ( current_user_can( $customField['capability'], $post_id ) ) {
if ( isset( $_POST[ $this->prefix . $customField['name'] ] ) && trim( $_POST[ 
$this->prefix . $customField['name'] ] ) ) {
update_post_meta( $post_id, $this->prefix . $customField[ 'name' ], $_POST[ 
$this->prefix . $customField['name'] ] );
} else {
delete_post_meta( $post_id, $this->prefix . $customField[ 'name' ] );
}
}
}

Answer 1

Thanks for your response, I like the more concise code, unfortunately it still does not work. It all looks correct when viewing the source...

<input type='checkbox'  name='eventsponsor[]' value='yes' style='width:
auto;border:0;' />

However nothing is saved to the database after clicking the update button. Any additional guidance would be greatly appreciated.

Answer 2

Looks like a simple syntax error. I've tidied up the code a bit and use WordPress' checked function. Try:

$sponsorselected = get_post_meta($post->ID, 'eventsponsor', $single = true);
$check =  (!empty($sponsorselected) && in_array($postslug,$sponsorselected) ? true : false);

echo "<input type='checkbox' ".checked($check,true,false)." name='{$this->prefix}{$customField['name']}[]' value='{$postslug}' style='width: auto;border:0;' />"

I've left the styling in, but I'm not sure it does anything..