From 2340f269cf5067ca2bae577c0a450a20f5583961 Mon Sep 17 00:00:00 2001
From: Ian Jenkins <ian.jenkins@boxuk.com>
Date: Wed, 30 Oct 2019 15:08:19 +0000
Subject: [PATCH] Add support for custom attributes to wc_placeholder_img().

When displaying a list of images you often want a specific class to be
attached to each image, therefore you pass through a custom class using
the attr parameter. Unfortunately this doesn't get passed through to a
placeholder image should one be needed. This means that, for example, if
you're custom class center an image or something, it won't be honoured
for placeholders, which can lead to some wonky image listings.

You can work around this currently by leverging the
`woocommerce_product_get_image` filter, but it's a bit gnarly as you
need to do some regexing or string splitting or something and checking
class names and what not. This provides a much easier way, by
supporting custom attrs on placeholder images as is the case for non
placehodler images.
---
 includes/abstracts/abstract-wc-product.php |  2 +-
 includes/wc-product-functions.php          | 25 ++++++++++++++++------
 tests/unit-tests/product/data.php          |  4 ++++
 tests/unit-tests/product/functions.php     |  4 ++++
 4 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/includes/abstracts/abstract-wc-product.php b/includes/abstracts/abstract-wc-product.php
index 50437cb570e..504fc66d466 100644
--- a/includes/abstracts/abstract-wc-product.php
+++ b/includes/abstracts/abstract-wc-product.php
@@ -1859,7 +1859,7 @@ class WC_Product extends WC_Abstract_Legacy_Product {
 		}
 
 		if ( ! $image && $placeholder ) {
-			$image = wc_placeholder_img( $size );
+			$image = wc_placeholder_img( $size, $attr );
 		}
 
 		return apply_filters( 'woocommerce_product_get_image', $image, $this, $size, $attr, $placeholder, $image );
diff --git a/includes/wc-product-functions.php b/includes/wc-product-functions.php
index 975ee6d9d57..3473da82697 100644
--- a/includes/wc-product-functions.php
+++ b/includes/wc-product-functions.php
@@ -288,26 +288,37 @@ function wc_placeholder_img_src( $size = 'woocommerce_thumbnail' ) {
  *
  * Uses wp_get_attachment_image if using an attachment ID @since 3.6.0 to handle responsiveness.
  *
- * @param string $size Image size.
+ * @param string       $size Image size.
+ * @param string|array $attr Optional. Attributes for the image markup. Default empty.
  * @return string
  */
-function wc_placeholder_img( $size = 'woocommerce_thumbnail' ) {
+function wc_placeholder_img( $size = 'woocommerce_thumbnail', $attr = '' ) {
 	$dimensions        = wc_get_image_size( $size );
 	$placeholder_image = get_option( 'woocommerce_placeholder_image', 0 );
 
+	$default_attr = array(
+		'class' => 'woocommerce-placeholder wp-post-image',
+		'alt'   => __( 'Placeholder', 'woocommerce' ),
+	);
+
+	$attr = wp_parse_args( $attr, $default_attr );
+
 	if ( wp_attachment_is_image( $placeholder_image ) ) {
 		$image_html = wp_get_attachment_image(
 			$placeholder_image,
 			$size,
 			false,
-			array(
-				'alt'   => __( 'Placeholder', 'woocommerce' ),
-				'class' => 'woocommerce-placeholder wp-post-image',
-			)
+			$attr
 		);
 	} else {
 		$image      = wc_placeholder_img_src( $size );
-		$image_html = '<img src="' . esc_attr( $image ) . '" alt="' . esc_attr__( 'Placeholder', 'woocommerce' ) . '" width="' . esc_attr( $dimensions['width'] ) . '" class="woocommerce-placeholder wp-post-image" height="' . esc_attr( $dimensions['height'] ) . '" />';
+		$hwstring   = image_hwstring( $dimensions['width'], $dimensions['height'] );
+		$attr = array_map( 'esc_attr', $attr );
+		$image_html = rtrim( '<img src="' . esc_attr( $image ) . '" ' . $hwstring );
+		foreach ( $attr as $name => $value ) {
+			$image_html .= " $name=" . '"' . $value . '"';
+		}
+		$image_html .= ' />';
 	}
 
 	return apply_filters( 'woocommerce_placeholder_img', $image_html, $size, $dimensions );
diff --git a/tests/unit-tests/product/data.php b/tests/unit-tests/product/data.php
index 86544dfe7b9..54c907e484b 100644
--- a/tests/unit-tests/product/data.php
+++ b/tests/unit-tests/product/data.php
@@ -324,6 +324,10 @@ class WC_Tests_Product_Data extends WC_Unit_Test_Case {
 		$product = new WC_Product();
 
 		$this->assertContains( wc_placeholder_img_src(), $product->get_image() );
+
+		// Test custom class attribute is honoured.
+		$image = $product->get_image( 'woocommerce_thumbnail', array( 'class' => 'custom-class' ) );
+		$this->assertContains( 'class="custom-class"', $image );
 	}
 
 	/**
diff --git a/tests/unit-tests/product/functions.php b/tests/unit-tests/product/functions.php
index 01ea4e0b40e..14b9ec2ddca 100644
--- a/tests/unit-tests/product/functions.php
+++ b/tests/unit-tests/product/functions.php
@@ -885,6 +885,10 @@ class WC_Tests_Product_Functions extends WC_Unit_Test_Case {
 	 */
 	public function test_wc_placeholder_img() {
 		$this->assertTrue( (bool) strstr( wc_placeholder_img(), wc_placeholder_img_src() ) );
+
+		// Test custom class attribute is honoured.
+		$attr = array( 'class' => 'custom-class' );
+		$this->assertContains( 'class="custom-class"', wc_placeholder_img( 'woocommerce_thumbnail', $attr ) );
 	}
 
 	/**