Fix validate url (#2957)

* Fix validate url

* Add unit test + fix impl

* Fix CHANGELOG

* Use head instead of get to check url

* Add head route for files

Co-authored-by: Abubakar Abid <abubakar@huggingface.co>

CHANGELOG.md

@@ -12,6 +12,7 @@ No changes to highlight.
 * Fixes bug where png files were not being recognized when uploading images by [@abidlabs](https://github.com/abidlabs) in [PR 3002](https://github.com/gradio-app/gradio/pull/3002) 
 * Fixes bug where temporary uploaded files were not being added to temp sets by [@abidlabs](https://github.com/abidlabs) in [PR 3005](https://github.com/gradio-app/gradio/pull/3005)
 * Fixes issue where markdown support in chatbot breaks older demos [@dawoodkhan82](https://github.com/dawoodkhan82) in [PR 3006](https://github.com/gradio-app/gradio/pull/3006) 
+* Fix bug where the Image component could not serialize image urls by [@freddyaboulton](https://github.com/freddyaboulton) in [PR 2957](https://github.com/gradio-app/gradio/pull/2957)  
 
 ## Documentation Changes:
 * SEO improvements to guides by[@aliabd](https://github.com/aliabd) in [PR 2915](https://github.com/gradio-app/gradio/pull/2915)

gradio/routes.py

@@ -255,6 +255,7 @@ class App(FastAPI):
             else:
                 return FileResponse(blocks.favicon_path)
 
+        @app.head("/file={path:path}", dependencies=[Depends(login_check)])
         @app.get("/file={path:path}", dependencies=[Depends(login_check)])
         async def file(path: str, request: fastapi.Request):
             abs_path = str(Path(path).resolve())

gradio/serializing.py

@@ -80,8 +80,10 @@ class ImgSerializable(Serializable):
         """
         if x is None or x == "":
             return None
+        is_url = utils.validate_url(x)
+        path = x if is_url else Path(load_dir) / x
         return processing_utils.encode_url_or_file_to_base64(
-            Path(load_dir) / x, encryption_key=encryption_key
+            path, encryption_key=encryption_key
         )
 
     def deserialize(

gradio/utils.py

@@ -710,7 +710,10 @@ def append_unique_suffix(name: str, list_of_names: List[str]):
 def validate_url(possible_url: str) -> bool:
     headers = {"User-Agent": "gradio (https://gradio.app/; team@gradio.app)"}
     try:
-        return requests.get(possible_url, headers=headers).ok
+        head_request = requests.head(possible_url, headers=headers)
+        if head_request.status_code == 405:
+            return requests.get(possible_url, headers=headers).ok
+        return head_request.ok
     except Exception:
         return False
 

test/test_components.py

@@ -668,6 +668,12 @@ class TestImage:
         image_output = gr.Image(type="numpy")
         assert image_output.postprocess(y_img).startswith("data:image/png;base64,")
 
+    @pytest.mark.flaky
+    def test_serialize_url(self):
+        img = "https://gradio.app/assets/img/header-image.jpg"
+        expected = processing_utils.encode_url_or_file_to_base64(img)
+        assert gr.Image().serialize(img) == expected
+
     def test_in_interface_as_input(self):
         """
         Interface, process, interpret