From ee7e05f9368ba1dbb5217c502e86667d12b51c98 Mon Sep 17 00:00:00 2001
From: Andrew Welch <andrew@nystudio107.com>
Date: Sat, 19 Oct 2024 19:33:56 -0400
Subject: [PATCH] feat: Allow for empty `alt` tags for screen readers as per
 WCAG ([411](https://github.com/nystudio107/craft-imageoptimize/issues/411))

---
 src/models/BaseTag.php        | 19 +++++++++++++++++++
 src/models/ImgTag.php         |  9 ++-------
 src/models/LinkPreloadTag.php |  2 +-
 src/models/PictureTag.php     |  9 ++-------
 4 files changed, 24 insertions(+), 15 deletions(-)

diff --git a/src/models/BaseTag.php b/src/models/BaseTag.php
index 1874439e..5ee1eec4 100644
--- a/src/models/BaseTag.php
+++ b/src/models/BaseTag.php
@@ -23,6 +23,11 @@ abstract class BaseTag extends Model implements TagInterface
 {
     use TagTrait;
 
+    /**
+     * Attributes that are allowed to be an empty string
+     */
+    protected const ALLOWED_EMPTY_ATTRS = ['alt'];
+
     /**
      * @return string
      */
@@ -40,4 +45,18 @@ public function render(): Markup
     {
         return Template::raw('');
     }
+
+    /**
+     * Filter out attributes with empty values in them, so they don't get rendered
+     *
+     * @param array $attrs
+     * @return array
+     */
+    public function filterEmptyAttributes(array $attrs): array
+    {
+        return array_filter($attrs, static function($value, $key) {
+            // Keep certain attributes even if they are empty
+            return in_array($key, self::ALLOWED_EMPTY_ATTRS, true) || !empty($value);
+        }, ARRAY_FILTER_USE_BOTH);
+    }
 }
diff --git a/src/models/ImgTag.php b/src/models/ImgTag.php
index d5ecdc1c..67a5c9c6 100644
--- a/src/models/ImgTag.php
+++ b/src/models/ImgTag.php
@@ -106,13 +106,8 @@ public function render(): Markup
         if ($this->loadingStrategy !== 'eager') {
             $attrs = $this->swapLazyLoadAttrs($this->loadingStrategy, $this->placeholder, $attrs);
         }
-
-        // Remove any empty attributes except the alt attribute
-        $attrs = array_filter($attrs, function($value, $key) {
-            // Keep the 'alt' attribute even if it's empty
-            return $key === 'alt' || !empty($value);
-        }, ARRAY_FILTER_USE_BOTH);
-        
+        // Remove any empty attributes
+        $attrs = $this->filterEmptyAttributes($attrs);
         // Render the tag
         $tag = Html::tag('img', '', $attrs);
 
diff --git a/src/models/LinkPreloadTag.php b/src/models/LinkPreloadTag.php
index 753574ee..042f6e54 100644
--- a/src/models/LinkPreloadTag.php
+++ b/src/models/LinkPreloadTag.php
@@ -70,7 +70,7 @@ public function render(): Markup
     {
         $attrs = $this->linkAttrs;
         // Remove any empty attributes
-        $attrs = array_filter($attrs);
+        $attrs = $this->filterEmptyAttributes($attrs);
         // Render the tag
         $tag = Html::tag('link', '', $attrs);
 
diff --git a/src/models/PictureTag.php b/src/models/PictureTag.php
index 846be1a8..9792959c 100644
--- a/src/models/PictureTag.php
+++ b/src/models/PictureTag.php
@@ -174,13 +174,8 @@ public function render(): Markup
         if ($this->loadingStrategy !== 'eager') {
             $attrs = $this->swapLazyLoadAttrs($this->loadingStrategy, $this->placeholder, $attrs);
         }
-
-        // Remove any empty attributes except the alt attribute
-        $attrs = array_filter($attrs, function($value, $key) {
-            // Keep the 'alt' attribute even if it's empty
-            return $key === 'alt' || !empty($value);
-        }, ARRAY_FILTER_USE_BOTH);
-
+        // Remove any empty attributes
+        $attrs = $this->filterEmptyAttributes($attrs);
         // Render the tag
         $content .= Html::tag('img', '', $attrs);
         // Handle the <picture> tag