Add default_alt_text to the state dictionary returned by ImageChooser view and used by AdminImageChooser widget

client/src/components/ChooserWidget/ImageChooserWidget.js

@@ -34,6 +34,9 @@ export class ImageChooser extends Chooser {
         width: this.previewImage.getAttribute('width'),
         height: this.previewImage.getAttribute('height'),
       };
+      state.default_alt_text = this.previewImage.getAttribute(
+        'data-default-alt-text',
+      );
     }
     return state;
   }
@@ -42,6 +45,10 @@ export class ImageChooser extends Chooser {
     super.renderState(newState);
     this.previewImage.setAttribute('src', newState.preview.url);
     this.previewImage.setAttribute('width', newState.preview.width);
+    this.previewImage.setAttribute(
+      'data-default-alt-text',
+      newState.default_alt_text,
+    );
   }
 }
 

wagtail/images/templates/wagtailimages/widgets/image_chooser.html

@@ -3,5 +3,5 @@
 
 {% block chosen_icon %}
     {# Empty alt because the chosen item’s title is already displayed next to the image. #}
-    <img class="chooser__image show-transparency" data-chooser-image alt="" decoding="async" height="{{ preview.height|unlocalize }}" src="{{ preview.url }}" width="{{ preview.width|unlocalize }}">
+    <img class="chooser__image show-transparency" data-chooser-image alt="" data-default-alt-text="{{ default_alt_text }}" decoding="async" height="{{ preview.height|unlocalize }}" src="{{ preview.url }}" width="{{ preview.width|unlocalize }}">
 {% endblock chosen_icon %}

wagtail/images/tests/test_admin_views.py

@@ -1876,6 +1876,7 @@ class TestImageChooserChosenView(WagtailTestUtils, TestCase):
         self.image = Image.objects.create(
             title="Test image",
             file=get_test_image_file(),
+            description="Test description",
         )
 
     def get(self, params={}):
@@ -1890,6 +1891,12 @@ class TestImageChooserChosenView(WagtailTestUtils, TestCase):
         response_json = json.loads(response.content.decode())
         self.assertEqual(response_json["step"], "chosen")
         self.assertEqual(response_json["result"]["title"], "Test image")
+        self.assertEqual(
+            set(response_json["result"]["preview"].keys()), {"url", "width", "height"}
+        )
+        self.assertEqual(
+            response_json["result"]["default_alt_text"], "Test description"
+        )
 
     def test_with_multiple_flag(self):
         # if 'multiple' is passed as a URL param, the result should be returned as a single-item list
@@ -1900,6 +1907,13 @@ class TestImageChooserChosenView(WagtailTestUtils, TestCase):
         self.assertEqual(response_json["step"], "chosen")
         self.assertEqual(len(response_json["result"]), 1)
         self.assertEqual(response_json["result"][0]["title"], "Test image")
+        self.assertEqual(
+            set(response_json["result"][0]["preview"].keys()),
+            {"url", "width", "height"},
+        )
+        self.assertEqual(
+            response_json["result"][0]["default_alt_text"], "Test description"
+        )
 
 
 class TestImageChooserChosenMultipleView(WagtailTestUtils, TestCase):
@@ -1910,15 +1924,18 @@ class TestImageChooserChosenMultipleView(WagtailTestUtils, TestCase):
         self.image1 = Image.objects.create(
             title="Test image",
             file=get_test_image_file(),
+            description="Test description",
         )
         self.image2 = Image.objects.create(
             title="Another test image",
             file=get_test_image_file(),
+            description="Another test description",
         )
 
         self.image3 = Image.objects.create(
             title="Unchosen test image",
             file=get_test_image_file(),
+            description="Unchosen test description",
         )
 
     def get(self, params={}):
@@ -1940,6 +1957,8 @@ class TestImageChooserChosenMultipleView(WagtailTestUtils, TestCase):
         self.assertEqual(len(response_json["result"]), 2)
         titles = {item["title"] for item in response_json["result"]}
         self.assertEqual(titles, {"Test image", "Another test image"})
+        alt_texts = {item["default_alt_text"] for item in response_json["result"]}
+        self.assertEqual(alt_texts, {"Test description", "Another test description"})
 
 
 class TestImageChooserSelectFormatView(WagtailTestUtils, TestCase):

wagtail/images/views/chooser.py

@@ -43,6 +43,7 @@ class ImageChosenResponseMixin(ChosenResponseMixin):
             "width": preview_image.width,
             "height": preview_image.height,
         }
+        response_data["default_alt_text"] = image.default_alt_text
         return response_data
 
 

wagtail/images/widgets.py

@@ -31,11 +31,13 @@ class AdminImageChooser(BaseChooser):
             "width": preview_image.width,
             "height": preview_image.height,
         }
+        data["default_alt_text"] = instance.default_alt_text
         return data
 
     def get_context(self, name, value_data, attrs):
         context = super().get_context(name, value_data, attrs)
         context["preview"] = value_data.get("preview", {})
+        context["default_alt_text"] = value_data.get("default_alt_text", "")
         return context
 
     @property