# Does the BlockingCallbackTransform dash extension work? **URL:** \ **Category:** Dash Python\ **Tags:** question\ **Created:** [November 17, 2022, 10:43pm UTC](https://community.plotly.com/t/does-the-blockingcallbacktransform-dash-extension-work/70013 "2022-11-17T22:43:34Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![ibenok](https://avatars.discourse-cdn.com/v4/letter/i/f17d59/32.png) [@ibenok](https://community.plotly.com/u/ibenok)\ **Post date:** [November 17, 2022, 10:43pm UTC](https://community.plotly.com/t/does-the-blockingcallbacktransform-dash-extension-work/70013/1 "2022-11-17T22:43:34Z")
I tried to use the extension listed here: [BlockingCallbackTransform](https://www.dash-extensions.com/pages/transforms/blocking-callback-transform) The blocking functionality works, but the context stopped working on my callbacks. Instead of giving the name of the trigger for ctx.trigger\_id, the blocking functionality causes it to delivere a different value instead. I’d like to use the extensions, but I’m concerned that I can’t because the trigger id doesn’t appear to work. ---
**Author:** ![Emil](https://sea2.discourse-cdn.com/flex024/user_avatar/community.plotly.com/emil/32/31734_2.png) [@Emil](https://community.plotly.com/u/Emil)\ **Post date:** [November 18, 2022, 12:17pm UTC](https://community.plotly.com/t/does-the-blockingcallbacktransform-dash-extension-work/70013/2 "2022-11-18T12:17:54Z")
That is true. Since the transform uses a separate triggering mechanism, the `ctx.trigger_id` will refer to that mechanism, not to the component that triggered the callback initially (which might be what you expected). ---
**Author:** ![ibenok](https://avatars.discourse-cdn.com/v4/letter/i/f17d59/32.png) [@ibenok](https://community.plotly.com/u/ibenok)\ **Post date:** [November 18, 2022, 8:07pm UTC](https://community.plotly.com/t/does-the-blockingcallbacktransform-dash-extension-work/70013/3 "2022-11-18T20:07:56Z")
Is there any way to use both the blocking callback transform extension and know what triggered the callback? If not, is it possible to setup a chain of callbacks instead? ---
**Author:** ![Emil](https://sea2.discourse-cdn.com/flex024/user_avatar/community.plotly.com/emil/32/31734_2.png) [@Emil](https://community.plotly.com/u/Emil)\ **Post date:** [November 18, 2022, 8:34pm UTC](https://community.plotly.com/t/does-the-blockingcallbacktransform-dash-extension-work/70013/4 "2022-11-18T20:34:01Z")
Not with the current implementation. But I believe it would be possible to add support for that ‘feature’ 🙃 ---
**Author:** ![jinnyzor](https://sea2.discourse-cdn.com/flex024/user_avatar/community.plotly.com/jinnyzor/32/21194_2.png) [@jinnyzor](https://community.plotly.com/u/jinnyzor)\ **Post date:** [November 18, 2022, 8:38pm UTC](https://community.plotly.com/t/does-the-blockingcallbacktransform-dash-extension-work/70013/5 "2022-11-18T20:38:14Z")
@Emil, Does blockingcallback block all other users from that same endpoint during the calculation of the one, or just that specific session? ---
**Author:** ![Emil](https://sea2.discourse-cdn.com/flex024/user_avatar/community.plotly.com/emil/32/31734_2.png) [@Emil](https://community.plotly.com/u/Emil)\ **Post date:** [November 18, 2022, 8:52pm UTC](https://community.plotly.com/t/does-the-blockingcallbacktransform-dash-extension-work/70013/6 "2022-11-18T20:52:49Z")
Just that specific session ---
**Author:** ![Emil](https://sea2.discourse-cdn.com/flex024/user_avatar/community.plotly.com/emil/32/31734_2.png) [@Emil](https://community.plotly.com/u/Emil)\ **Post date:** [November 29, 2022, 1:56pm UTC](https://community.plotly.com/t/does-the-blockingcallbacktransform-dash-extension-work/70013/7 "2022-11-29T13:56:53Z")
I have started working on a solution. Could you try to see, if `dash-extensions==0.1.8rc1` resolves your usecase?