add chained events

myapp/app.py

@@ -1,3 +1,4 @@
+from functools import partial
 from pathlib import Path
 from tempfile import NamedTemporaryFile
 from typing import Any
@@ -24,26 +25,25 @@ with gr.Blocks() as demo:
             text = gr.Textbox(
                 "https://wheelingvultures.bandcamp.com/album/ep", label="Text"
             )
-            prompt = gr.TextArea("A vulture in black and white", label="Prompt")
+            prompt = gr.TextArea("A psychedelic vulture", label="Prompt")
             button = gr.Button("Generate")
         with gr.Column():
             background = gr.Image(visible=False, type="filepath")
             scale = gr.Slider(3, 15, 9, step=1, label="Scale")
             output = gr.Image()
 
-    @gr.on(
-        triggers=[button.click, prompt.submit],
+    gr.on(
+        [button.click, prompt.submit],
+        partial(gr.update, interactive=False),
+        outputs=button,
+    ).then(
+        partial(client.text_to_image, width=400, height=400),
         inputs=prompt,
-        outputs=[button, background],
+        outputs=background,
+    ).then(
+        partial(gr.update, interactive=True),
+        outputs=button,
     )
-    def generate_background(prompt):
-        yield gr.update(interactive=False), None
-        response = None
-
-        try:
-            response = client.text_to_image(prompt, width=400, height=400)
-        finally:
-            yield gr.update(interactive=True), response
 
     @gr.on(
         triggers=[text.submit, background.change, scale.change],
@@ -51,7 +51,7 @@ with gr.Blocks() as demo:
         outputs=output,
     )
     def generate_code(data: dict[Component, Any]):
-        if data[background] is None:
+        if data.get(background) is None:
             return None
 
         qr_code = segno.make(data[text], error="h")