Wordpress Custom Metabox Checkbox Save Issue - php

Question

I have a custom metabox that I created and have been using on my website for a while, but there's a bit of an issue with how it saves. It tends to be rather volatile, meaning that when backing-up with xml or bulk-editing, it will always lose the data.
The following is the code that I use for the checkbox and to save it
function member_page_featured_meta() {
add_meta_box( 'member_page_meta', __( 'Page Template (if default, select none)', 'member_page_textdomain' ), 'member_page_meta_callback', 'page', 'side', 'low' );
}
add_action( 'add_meta_boxes', 'member_page_featured_meta' );
/**
* Outputs the content of the meta box
*/
function member_page_meta_callback( $post ) {
$values = get_post_meta( $post->ID );
$check = isset( $values['member_box_check'] ) ? esc_attr( $values['member_box_check'][0] ) : '';
wp_nonce_field( basename( __FILE__ ), 'member_page_nonce' );
$member_page_stored_meta = get_post_meta( $post->ID );
?>
<p>
<div class="member_page-row-content">
<label for="featured-checkbox">
<input type="checkbox" name="featured-checkbox" id="featured-checkbox" value="yes" <?php if ( isset ( $member_page_stored_meta['featured-checkbox'] ) ) checked( $member_page_stored_meta['featured-checkbox'][0], 'yes' ); ?> />
<?php _e( 'Member Page', 'member_page_textdomain' )?>
</label><br />
<label for="list-checkbox">
<input type="checkbox" name="list-checkbox" id="list-checkbox" value="yes" <?php if ( isset ( $member_page_stored_meta['list-checkbox'] ) ) checked( $member_page_stored_meta['list-checkbox'][0], 'yes' ); ?> />
<?php _e( 'Home List', 'member_page_textdomain' )?>
</label><br />
</div>
</p>
<?php
}
/**
* Saves the custom meta input
*/
function member_page_meta_save( $post_id ) {
// Checks save status - overcome autosave, etc.
$is_autosave = wp_is_post_autosave( $post_id );
$is_revision = wp_is_post_revision( $post_id );
$is_valid_nonce = ( isset( $_POST[ 'member_page_nonce' ] ) && wp_verify_nonce( $_POST[ 'member_page_nonce' ], basename( __FILE__ ) ) ) ? 'true' : 'false';
// Exits script depending on save status
if ( $is_autosave || $is_revision || !$is_valid_nonce ) {
return;
}
// Checks for input and saves - save checked as yes and unchecked at no
//This line of code is my hack (just keeps the boxes from saving pretty much)
//if (!empty($_POST['featured-checkbox']) && !empty($_POST['list-checkbox'])) {
if( isset( $_POST[ 'featured-checkbox' ] ) ) {
update_post_meta( $post_id, 'featured-checkbox', 'yes' );
} else {
update_post_meta( $post_id, 'featured-checkbox', 'no' );
};
if( isset( $_POST[ 'list-checkbox' ] ) ) {
update_post_meta( $post_id, 'list-checkbox', 'yes' );
} else {
update_post_meta( $post_id, 'list-checkbox', 'no' );
};
// (bracket ending the first if statement) }
}
add_action( 'save_post', 'member_page_meta_save' );
Is there any way to prevent this issue from happening or is it just something that has to be dealt with when saving check-boxes?
I've sorted out a bit of a hack that is working for now, but whenever I need to make changes to the check-boxes (which is fairly often by the nature of how they're used), I have to comment out a few lines of code, make the change, then un-comment the lines of code and it's a bit unconventional.
I mostly need to make it work when backing-up and restoring (on my backup/production website).

Answer 1

The save_post action is triggered when a post is created or updated, so quick edits and regular edits and the import of posts will trigger it too.
It is actually your script which clears the post meta when doing a quick edit or import, because the POST array does not contain the previously saved values of the checkboxes.
To solve this, you might want to know the "type of saving" currently happening, and only update the post meta when you are on the post edit screen in the admin area. A way of doing this is to check the action parameter of the POST array like the following, because the action parameter only has the value editpost when saving from a post edit screen:
if (filter_input(INPUT_POST, 'action') != 'editpost') {
return;
}
Putting this code at the beginning of the function hooked to the save_post action (member_page_meta_save in your case) will let the rest of the function run only when saving from the post edit screen.