Handle stock for self and children, as well as syncing status with the children

includes/class-wc-product-variable.php

@@ -22,9 +22,8 @@ class WC_Product_Variable extends WC_Product {
 	public $total_stock;
 
 	/**
-	 * __construct function.
+	 * Constructor
 	 *
-	 * @access public
 	 * @param mixed $product
 	 */
 	public function __construct( $product ) {
@@ -51,24 +50,20 @@ class WC_Product_Variable extends WC_Product {
      * @return int
      */
     public function get_total_stock() {
-
         if ( empty( $this->total_stock ) ) {
-
         	$transient_name = 'wc_product_total_stock_' . $this->id;
 
         	if ( false === ( $this->total_stock = get_transient( $transient_name ) ) ) {
-		        $this->total_stock = $this->stock;
+		        $this->total_stock = max( 0, intval( $this->stock ) );
 
 				if ( sizeof( $this->get_children() ) > 0 ) {
 					foreach ( $this->get_children() as $child_id ) {
+						if ( 'yes' === get_post_meta( $child_id, '_manage_stock', true ) ) {
 							$stock = get_post_meta( $child_id, '_stock', true );
-
+							$this->total_stock += max( 0, intval( $stock ) );
-						if ( $stock != '' ) {
-							$this->total_stock += intval( $stock );
 						}
 					}
 				}
-
 				set_transient( $transient_name, $this->total_stock, YEAR_IN_SECONDS );
 			}
 		}
@@ -82,14 +77,50 @@ class WC_Product_Variable extends WC_Product {
 	 * @param string $mode can be set, add, or subtract
 	 * @return int Stock
 	 */
-	function set_stock( $amount = null, $mode = 'set' ) {
+	public function set_stock( $amount = null, $mode = 'set' ) {
-		// Empty total stock so its refreshed
 		$this->total_stock = '';
-
+		delete_transient( 'wc_product_total_stock_' . $this->id );
-		// Call parent set_stock
 		return parent::set_stock( $amount, $mode );
 	}
 
+	/**
+	 * Performed after a stock level change at product level
+	 */
+	protected function check_stock_status() {
+		$set_child_stock_status = '';
+
+		if ( ! $this->backorders_allowed() && $this->get_stock_quantity() <= get_option( 'woocommerce_notify_no_stock_amount' ) ) {
+			$set_child_stock_status = 'outofstock';
+		} elseif ( $this->backorders_allowed() || $this->get_stock_quantity() > get_option( 'woocommerce_notify_no_stock_amount' ) ) {
+			$set_child_stock_status = 'instock';
+		}
+
+		if ( $set_child_stock_status ) {
+			foreach ( $this->get_children() as $child_id ) {
+				if ( 'yes' !== get_post_meta( $child_id, '_manage_stock', true ) ) {
+					wc_update_product_stock_status( $child_id, $set_child_stock_status );
+				}
+			}
+
+			// Children statuses changed, so sync self
+			self::sync_stock_status( $this->id );
+		}
+	}
+
+	/**
+	 * set_stock_status function.
+	 *
+	 * @access public
+	 * @return void
+	 */
+	public function set_stock_status( $status ) {
+		$status = ( 'outofstock' === $status ) ? 'outofstock' : 'instock';
+
+		if ( update_post_meta( $this->id, '_stock_status', $status ) ) {
+			do_action( 'woocommerce_product_set_stock_status', $this->id, $status );
+		}
+	}
+
 	/**
 	 * Return the products children posts.
 	 *
@@ -97,11 +128,9 @@ class WC_Product_Variable extends WC_Product {
 	 * @return array of children ids
 	 */
 	public function get_children( $visible_only = false ) {
-		$variable = $visible_only ? 'visible_children' : 'children';
+		if ( ! is_array( $this->children ) ) {
-
+			$this->children = array();
-		if ( ! is_array( $this->$variable ) ) {
+			$transient_name = 'wc_product_children_ids_' . $this->id;
-			$this->$variable = array();
-			$transient_name  = 'wc_product_' . $variable . '_ids_' . $this->id;
 
         	if ( false === ( $this->children = get_transient( $transient_name ) ) ) {
 		        $args = array(
@@ -114,23 +143,28 @@ class WC_Product_Variable extends WC_Product {
 					'numberposts' => -1
 		        );
 
-				if ( $visible_only && 'yes' === get_option( 'woocommerce_hide_out_of_stock_items' ) ) {
+				$this->children = get_posts( $args );
-					$args['meta_query'] = array(
-						array(
-							'key'     => '_stock_status',
-							'value'   => 'instock',
-							'compare' => '='
-					    )
-					);
-				}
 
-				$this->$variable = get_posts( $args );
+				set_transient( $transient_name, $this->children, YEAR_IN_SECONDS );
-
-				set_transient( $transient_name, $this->$variable, YEAR_IN_SECONDS );
 			}
 		}
 
-		return $this->$variable;
+		if ( $visible_only ) {
+			$children = array();
+			foreach( $this->children as $child_id ) {
+				if ( 'yes' === get_post_meta( $child_id, '_manage_stock', true ) ) {
+					if ( 'instock' === get_post_meta( $child_id, '_stock_status', true ) ) {
+						$children[] = $child_id;
+					}
+				} elseif ( $this->is_in_stock() ) {
+					$children[] = $child_id;
+				}
+			}
+		} else {
+			$children = $this->children;
+		}
+
+		return $children;
 	}
 
 
@@ -396,7 +430,10 @@ class WC_Product_Variable extends WC_Product {
 
 			$variation = $this->get_child( $child_id );
 
-			if ( ! empty( $variation->variation_id ) ) {
+			if ( empty( $variation->variation_id ) || ( 'yes' === get_option( 'woocommerce_hide_out_of_stock_items' ) && ! $variation->is_in_stock() ) ) {
+				continue;
+			}
+				
 			$variation_attributes 	= $variation->get_variation_attributes();
 			$availability 			= $variation->get_availability();
 			$availability_html 		= empty( $availability['availability'] ) ? '' : apply_filters( 'woocommerce_stock_html', '<p class="stock ' . esc_attr( $availability['class'] ) . '">'. wp_kses_post( $availability['availability'] ).'</p>', wp_kses_post( $availability['availability'] ) );
@@ -439,7 +476,6 @@ class WC_Product_Variable extends WC_Product {
 				'is_sold_individually' => $variation->is_sold_individually() ? 'yes' : 'no',
 			), $this, $variation );
 		}
-		}
 
 		return $available_variations;
     }
@@ -469,6 +505,33 @@ class WC_Product_Variable extends WC_Product {
 		}
 	}
 
+	/**
+	 * Sync variable product stock status with children
+	 * @param  int $product_id
+	 */
+	public static function sync_stock_status( $product_id ) {
+		$children = get_posts( array(
+			'post_parent' 	=> $product_id,
+			'posts_per_page'=> -1,
+			'post_type' 	=> 'product_variation',
+			'fields' 		=> 'ids',
+			'post_status'	=> 'publish'
+		) );
+
+		$stock_status = 'outofstock';
+		
+		foreach ( $children as $child_id ) {
+			$child_stock_status = get_post_meta( $child_id, '_stock_status', true );
+			$child_stock_status = $child_stock_status ? $child_stock_status : 'instock';
+			if ( 'instock' === $child_stock_status ) {
+				$stock_status = 'instock';
+				break;
+			}
+		}
+
+		wc_update_product_stock_status( $product_id, $stock_status );
+	}
+
 	/**
 	 * Sync the variable product with it's children
 	 */