Fixes cancels to work with multiple blocks (#2530)

* fixes cancels to work with multiple blocks

* formatting and changelog

* formatting and test

* skip test in 3.7

CHANGELOG.md

@@ -50,8 +50,9 @@ inference time of 80 seconds).
 
 ## Bug Fixes:
 * Fixes issue where plotly animations, interactivity, titles, legends, were not working properly. [@dawoodkhan82](https://github.com/dawoodkhan82) in [PR 2486](https://github.com/gradio-app/gradio/pull/2486)
-* Prevent requests to the `/api` endpoint from skipping the queue if the queue is enabled for that event 
-   by [@freddyaboulton](https://github.com/freddyaboulton) in [PR 2493](https://github.com/gradio-app/gradio/pull/2493)
+* Prevent requests to the `/api` endpoint from skipping the queue if the queue is enabled for that event by [@freddyaboulton](https://github.com/freddyaboulton) in [PR 2493](https://github.com/gradio-app/gradio/pull/2493)
+* Fixes a bug with `cancels` in event triggers so that it works properly if multiple
+Blocks are rendered by [@abidlabs](https://github.com/abidlabs) in [PR 2530](https://github.com/gradio-app/gradio/pull/2530)  
 
 ## Documentation Changes:
 * Added an example interactive dashboard to the "Tabular & Plots" section of the Demos page by [@freddyaboulton](https://github.com/freddyaboulton) in [PR 2508](https://github.com/gradio-app/gradio/pull/2508)

gradio/blocks.py

@@ -621,6 +621,7 @@ class Blocks(BlockContext):
 
             Context.root_block.blocks.update(self.blocks)
             Context.root_block.fns.extend(self.fns)
+            dependency_offset = len(Context.root_block.dependencies)
             for dependency in self.dependencies:
                 api_name = dependency["api_name"]
                 if api_name is not None:
@@ -635,6 +636,9 @@ class Blocks(BlockContext):
                             )
                         )
                         dependency["api_name"] = api_name_
+                dependency["cancels"] = [
+                    c + dependency_offset for c in dependency["cancels"]
+                ]
                 Context.root_block.dependencies.append(dependency)
             Context.root_block.temp_dirs = Context.root_block.temp_dirs | self.temp_dirs
 

test/test_blocks.py

@@ -760,6 +760,40 @@ class TestCancel:
         captured = capsys.readouterr()
         assert "HELLO FROM LONG JOB" not in captured.out
 
+    @pytest.mark.skipif(
+        sys.version_info < (3, 8),
+        reason="Tasks dont have names in 3.7",
+    )
+    @pytest.mark.asyncio
+    async def test_cancel_function_with_multiple_blocks(self, capsys):
+        async def long_job():
+            await asyncio.sleep(10)
+            print("HELLO FROM LONG JOB")
+
+        with gr.Blocks() as demo1:
+            textbox = gr.Textbox()
+            button1 = gr.Button(value="Start")
+            button1.click(lambda x: x, textbox, textbox)
+        with gr.Blocks() as demo2:
+            button2 = gr.Button(value="Start")
+            click = button2.click(long_job, None, None)
+            cancel = gr.Button(value="Cancel")
+            cancel.click(None, None, None, cancels=[click])
+
+        with gr.Blocks() as demo:
+            with gr.Tab("Demo 1"):
+                demo1.render()
+            with gr.Tab("Demo 2"):
+                demo2.render()
+
+        cancel_fun = demo.fns[-1].fn
+
+        task = asyncio.create_task(long_job())
+        task.set_name("foo_0")
+        await asyncio.gather(task, cancel_fun("foo"), return_exceptions=True)
+        captured = capsys.readouterr()
+        assert "HELLO FROM LONG JOB" not in captured.out
+
     def test_raise_exception_if_cancelling_an_event_thats_not_queued(self):
         def iteration(a):
             yield a