Woocommerce: save_post hook is not being triggered - php

Question

I have a meta box I'm coding for the product post type that comes with woocommerce. I've run into a problem I can't pass in that the 'save_post' hook does not seem to be working at all with products. It works perfectly for posts, but since I've changed my code to work for products it does nothing. The save_post function I've hooked to does absolutely nothing at the moment. I've added all sorts of code to it and it doesn't matter, the script just doesn't seem to get that far. am I missing something obvious?
Edit: as an aside, I added
?> <script type="text/javascript">
var post_id = '<?php $post_id ?>';
console.log("id is: " + post_id );
</script><?php
But it returns absolutely nothing.
<?php
/*
* Represents the plugin's Meta Box
*
* #since 0.0.1
* #package BBPlugin
* #subpackage BBPlugin
* #author Christopher Dando <captaindando#gmail.com>
*/
/*
* Represents the plugin's Meta Box
*
* Register's the meta box with the WordPress API, sets its properties,
* by including the markup from its associated view
*
* #package BBPlugin
* #subpackage BBPlugin/admin
* #author Christopher Dando <captaindando#gmail.com>
*/
class BBPlugin_Meta_Box{
/*
* Register this class with the wordpress API
*
* #since 0.0.1
*/
public function initialize_hooks(){
//add_action( 'add_meta_boxes_product', array( $this, 'add_meta_box' ) );
add_action( 'add_meta_boxes', array( $this, 'BBadd_meta_box' ) );
// This checks when wordpress is saving or
// updating a post.
add_action( 'save_post', array( $this, 'save_post' ) );
$junk = $post_id;
?> <script type="text/javascript">
var post_id = '<?php global $post; echo $post->ID; ?>';
console.log("id is: " + post_id );
</script><?php
}
// add_meta_boxes is the wordpress function. add_meta_box is our new function
/*
* The function responsible for creating the actual meta box.
*
* #since 0.0.1
*/
public function BBadd_meta_box(){
?> <script>console.log("meta box added");</script><?php
add_meta_box(
'BBPlugin',
"Brave Books",
array( $this, 'display_meta_box' ),
'product',
'normal',
'default'
);
}
// This defines the properties of the meta box.
/*
* Renders the content of the meta box.
*
* #since 0.0.1
*/
public function display_meta_box(){
include_once( 'views/BBPlugin-navigation.php' );
}
/**
* Sanitizes and serializes the information associated with this post.
*
* #since 0.0.1
*
* #param int $post_id The ID of the post that's currently being edited.
*/
// strangely, this calls if the meta box does not render
public function save_post( $post_id ) {
?><script>alert("post saved");</script><?php
/* If we're not working with a 'product' post type or the
user doesn't have permission to save,
then we exit the function.
*/
if ( ! $this->user_can_save( $post_id, 'BBPlugin_nonce', 'BBPlugin_save' ) ) {
return;
}
/*
We need to 'Sanitise' our information before
we can save it to the database. What this means
is that we must strip it of html tags
and extract the text itself.
*/
// If the 'Resources' inputs exist, iterate through them and sanitize them
if ($this->value_exists( 'BBPlugin-resources' ) ) {
// This is all divs with the id of meta-box-resources
$this->update_post_meta(
$post_id,
'BBPlugin-resources',
$this->sanitize_data( 'BBPlugin-resources', true )
);
}
else {
// leaving an input blank on the front end will remove that specific input.
$this->delete_post_meta( $post_id, 'BBPlugin-resources' );
}
}
/**
* Determines whether or not a value exists in the $_POST collection
* identified by the specified key.
*
* #since 0.0.1
*
* #param string $key The key of the value in the $_POST collection.
* #return bool True if the value exists; otherwise, false.
*/
private function value_exists( $key ) {
return ! empty( $_POST[ $key ] );
}
/**
* Deletes the specified meta data associated with the specified post ID
* based on the incoming key.
*
* #since 0.0.1
* #access private
* #param int $post_id The ID of the post containing the meta data
* #param string $meta_key The ID of the meta data value
*/
private function delete_post_meta( $post_id, $meta_key ) {
if ( '' !== get_post_meta( $post_id, $meta_key, true ) ) {
delete_post_meta( $post_id, '$meta_key' );
}
}
private function update_post_meta( $post_id, $meta_key, $meta_value ) {
if ( is_array( $_POST[ $meta_key ] ) ) {
$meta_value = array_filter( $_POST[ $meta_key ] );
}
/*
Update_post_meta also adds to a database if there is nothing there already.
parameters are as follows:
1. The post ID used to associate this information with the post.
2. A meta key that's used to uniquely identify the value.
3. The actual value associated with the meta key.
*/
update_post_meta( $post_id, $meta_key, $meta_value );
}
/**
* Sanitizes the data in the $_POST collection identified by the specified key
* based on whether or not the data is text or is an array.
*
* #since 1.0.0
* #access private
* #param string $key The key used to retrieve the data from the $_POST collection.
* #param bool $is_array Optional. True if the incoming data is an array.
* #return array|string The sanitized data.
*/
private function sanitize_data( $key, $is_array = false ) {
$sanitized_data = null;
if ( $is_array ) {
$resources = $_POST[ $key ];
$sanitized_data = array();
foreach ( $resources as $resource ) {
$resource = esc_url( strip_tags( $resource ) );
if ( ! empty( $resource ) ) {
$sanitized_data[] = $resource;
}
}
}
else {
$sanitized_data = '';
$sanitized_data = trim( $_POST[ $key ] );
$sanitized_data = esc_textarea( strip_tags( $sanitized_data ) );
}
return $sanitized_data;
}
/**
* Verifies that the post type that's being saved is actually a post (versus a page or another
* custom post type.
*
*
* #since 0.0.1
* #access private
* #return bool Return if the current post type is a post; false, otherwise.
*/
private function is_valid_post_type() {
return ! empty( $_POST['post_type'] ) && 'post' == $_POST['post_type'];
}
/**
* Determines whether or not the current user has the ability to save meta data associated with this post.
*
* #since 0.0.1
* #access private
* #param int $post_id The ID of the post being save
* #param string $nonce_action The name of the action associated with the nonce.
* #param string $nonce_id The ID of the nonce field.
* #return bool Whether or not the user has the ability to save this post.
*/
private function user_can_save( $post_id, $nonce_action, $nonce_id ) {
$is_autosave = wp_is_post_autosave( $post_id );
$is_revision = wp_is_post_revision( $post_id );
$is_valid_nonce = ( isset( $_POST[ $nonce_action ] ) && wp_verify_nonce( $_POST[ $nonce_action ], $nonce_id ) );
// Return true if the user is able to save; otherwise, false.
return ! ( $is_autosave || $is_revision ) && $this->is_valid_post_type() && $is_valid_nonce;
}
}
?>

Answer 1

In Wordpress, save_post isn't a destination in itself; it is an action carried out effectively 'between' pages: you hit Update, and Wordpress will carry out a series of actions behind the scenes before returning you to the appropriate page (invariably the post you were just editing, with a notification about the status of that save).
As such, you will never see the results of an echo, print_r, or JS alert or console.log, because save_post isn't a user-facing action.
If you want to see if your save_post action is being carried out in this way, I would recommend throwing in a die(), like so:
public function save_post($post_id) {
?><script>alert("post saved");</script><?php
die();
}
If the save_post action is being fired correctly, then you should see the JS alert over a blank page. If you want to see if your function is carrying out any actual Wordpress-style functionality, I'd recommend a simple update_post_meta to confirm:
public function save_post($post_id) {
// Insert some actual logic to ensure you're not doing this on every post all the time
update_post_meta($post_id, 'i_am_saved', 'totes saved to post #' . $post_id);
}
You can then check the database (or click to view the custom fields within that post) to see if your custom metadata has been added.
I would also recommend attaching your save_post action specifically to the product post type that's used by WooCommerce:
add_action('save_post_product', array($this, 'save_post'));
That will save some redundancy checking later.