LWC EmpApi does not work when there is an Aura component using EmpApi #1618

AllanOricil · 2019-11-16T13:07:10Z

Description

LWC can't subscribe to a Platform Event if there is an Aura component that is subscribing to a Platform event in the same Lightning Page.

Steps to Reproduce

Place an Aura component that subscribes to a Platform Event 1 and a LWC that subscribes to a Platform Event 2 in a Lightning Page. The Aura component subscribed without any problem. The LWC did not subscribe and also did not display any error message or exception. Once I removed the Aura component from the Lightning Page, saved it, and reloaded it, the LWC subscribed to the Platform Event. Bear in mind I did not change anything in the LWC. I just removed the Aura component from the Lightning Page.

I followed the instructions to build the LWC component from here:
https://developer.salesforce.com/docs/component-library/bundle/lightning-emp-api/documentation

And I made the correction to my component that is described here:
https://developer.salesforce.com/forums/ForumsMain?id=9062I000000Xm9eQAC

Again, the LWC code is working! but only if I remove the Aura component from the Lightning Page.

Expected Results

LWC should subscribe to the Platform Event

Actual Results

LWC does not subscribe to the Platform Event and also does not show an errror message or exception

AllanOricil · 2019-11-16T16:47:57Z

To solve my issue for now I just put my LWC into another Lightning Page. It works but an odd behavior happens.

When I load a page which has an Aura component that subscribes to a Platform Event using empApi and then move to another lightning page that has a LWC using empApi, this page throws an exception. If I reload this last lightning page the error is gone.

This is the exception that I have:

miteshmsharma · 2019-11-17T04:46:47Z

This was once happening with me and the reason for this was that upon the navigation the sequence of lifecycle events were not coordinated in the navigation logic. I used state to capture current and cleared the previous states altogether. If your component has state before the navigation I recommend to set it to the conducive state for the next component(page). The other thing which might be at play here is that you are going from an Aura component to LWC and if any of the event is set to bubble true then that might also be causing the call back within smartstore.customer bucket (Parent assumed hereas its ) that is probably due to a handled event down the container hierarchy not stopped explicitly by event.stopPropagation()

…

On Sat, Nov 16, 2019 at 10:18 PM AllanOricil ***@***.***> wrote: To solve my issue for now I just put my LWC into another Lightning Page. It works but an odd behavior happens. When I load a page which has an Aura component that subscribes to a Platform Event using empApi and then move to another lightning page that has a LWC using empApi, this page throws an exception. If I reload this last lightning page the error is gone. This is the exception that I have: [image: image] <https://user-images.githubusercontent.com/55927613/68996355-bdbfd500-0890-11ea-987b-dbd775f4faf3.png> — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#1618?email_source=notifications&email_token=ABRIU6FWRCHPDOJDRCQO3STQUAP4BA5CNFSM4JOFDGJKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEEHVQVQ#issuecomment-554653782>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABRIU6CFKF2NYURL6P5OXJ3QUAP4BANCNFSM4JOFDGJA> .

-- Regards Mitesh Sharma

AllanOricil · 2019-11-17T10:50:39Z

The components don't not communicate with each other! They are completly separated and both subscribe to different platform events. And both work when they are in separated Lightning Pages.
But if I switch from a Lightning page that has an Aura to a Lightning page that has the LWC it throws that above exception. Then if I reload the Lightning Page with the LWC the error is just gone...

My workaround was to transform my Aura to a LWC and everything worked perfectly. So my conclusion is, don't mix Aura and LWC components in a Lightning Page when they are both subscribing to Platform Events. This seems to be a bug.

joeferraro · 2020-04-06T18:48:50Z

We're having this exact same issue in console. Our steps to reproduce:

Open a console app
Open a console main tab that has a non-namespaced Aura component that subscribes to the empApi when it initializes
Open a separate console main tab that has a namespaced LWC component that subscribes to the empApi when a button is clicked
Click the button in the namespaced LWC component that subscribes to the empApi
Receive the following exception:

Method Promise.prototype.then called on incompatible receiver [object Object]

cc @cdelmoral @adamsheets89 @yippie

caridy · 2020-04-06T21:38:50Z

By looking at the error message, this seems like a problem with proxies. Promise.prototype.then expects a branded promise object, but it is receiving a proxy of it most likely, which is not branded. This could be locker service doing the wrong thing.

joeferraro · 2020-04-08T14:11:45Z

I have a suspicion this may have something to do with namespaces (at least in relation to the steps to reproduce I laid out above). I am unable to reproduce this issue when the Aura component subscribing is using the same namespace as the LWC component.

caridy · 2020-04-08T16:19:41Z

cc @seksenov @manuel-jasso to see if he can re-route this issue to the proper queue, this is definitely not LWC.

manuel-jasso · 2020-04-09T14:43:20Z

@seksenov @caridy Tracking on W-7429747

vc4u · 2020-05-30T21:24:29Z

Any updates on when this could be fixed? In my use case, I could reproduce this in Summer pre-release org as well.

My environment is set to use an already existing Background Utility Item Aura Component. And I'm building a new LWC component which needs to subscribe to a Change Data Event, now, both are conflicting, and LWC emp-api component is throwing the same error as mentioned above:

Method Promise.prototype.then called on incompatible receiver

AllanOricil · 2020-05-30T22:30:34Z

When I discovered this issue I wasn't using namespaces.

arneper · 2020-05-31T18:04:13Z

seeing exactly same issue even when it is only component on page. @AllanOricil
Thanks for any help!

seksenov · 2020-06-01T16:51:38Z

The Lightning Locker team is tracking and investigating the issue. When we have an update to share on potential resolutions and timeline we will do so.

arneper · 2020-06-01T17:20:44Z

@seksenov thanks! It is appreciated

manuel-jasso · 2020-07-09T20:52:37Z

Hi @AllanOricil, I am from Locker team, I would like to reproduce this issue, is there an environment you can point me to and steps to reproduce? Ideally, I would like to do that on my local, do you have a repo with code that I can clone and run? I understand this may be part of a large app, I'm just trying to see if we can narrow it down. Also looks like others like @joeferraro may have a similar/simpler way to reproduce?

AllanOricil · 2020-07-09T21:16:51Z

Hi @AllanOricil, I am from Locker team, I would like to reproduce this issue, is there an environment you can point me to and steps to reproduce? Ideally, I would like to do that on my local, do you have a repo with code that I can clone and run? I understand this may be part of a large app, I'm just trying to see if we can narrow it down. Also looks like others like @joeferraro may have a similar/simpler way to reproduce?

HI @manuel-jasso. I did it a long time ago. I will try to find the environment. But you can follow these steps to get the error.

Create Platform Event 1 and Platform Event 2.
Create a Lightning Page.
Add an Aura Component that subscribes to Platform Event 1 to this page.
Add a LWC that subscribes to Platform Event 2 to this page. Don't forget to apply the fix that was posted here to your LWC.
Check that the Aura Component subscribed and the LWC did not. Also, the LWC didn't display any error message.

To understand that this was a problem caused by mixing LWC and Aura components to the same lightning page, and not my code, I placed both in separate Lightning Pages, and both worked perfectly fine. But then an unexpected behavior started to happen.

To reproduce this one do the following:

Go to your Lightning Page 1, which has the Aura component that subscribes to the Platform Event 1.
Then "navigate to" the Lightning Page 2, that has a LWC that subscribes to the Platform Event 2.
The error message will appear.
Reload the Lightning Page 2 and check that the error is gone.

manuel-jasso · 2020-07-09T21:54:12Z

Thanks @AllanOricil, kudos to @p-wu-214 (also from Locker) who was able to repro internally, so we can debug...

AllanOricil · 2020-07-10T03:01:07Z

Thanks @AllanOricil, kudos to @p-wu-214 (also from Locker) who was able to repro internally, so we can debug...

@manuel-jasso no problem. I hope it is not too hard to fix it. But you guys can do it! Good luck. Hope to hear the issue was solved soon.

arcadeteddy · 2020-07-21T22:23:15Z

@AllanOricil Hey! An update: We debugged the problem, which was an unwrapped promise, and have a fix. Once the fix is in, we will repro the error you are running into and make sure it is working. Will keep you updated when it is tested in the environment and we backport it to an earlier release. Thank you!

AllanOricil · 2020-07-21T23:18:42Z

@AllanOricil Hey! An update: We debugged the problem, which was an unwrapped promise, and have a fix. Once the fix is in, we will repro the error you are running into and make sure it is working. Will keep you updated when it is tested in the environment and we backport it to an earlier release. Thank you!

@arcadeteddy nice! well done guys.

gyadav4 · 2020-08-04T07:28:22Z

Hey there, any updates?

arcadeteddy · 2020-08-05T16:25:55Z

@gyadav4 Hey, so the fixes are in! We decided on not back porting it because it touches a critical part of the filtering mechanism.

AllanOricil · 2020-08-05T20:23:48Z

@gyadav4 Hey, so the fixes are in! We decided on not back porting it because it touches a critical part of the filtering mechanism.

What do you mean "not back porting"? Does it mean we can't work with aura and lwc on the same page when using the emp api?

caridy · 2020-08-05T20:32:12Z

@AllanOricil it means that we will not fix it in current production code, but in the upcoming release only, which might take a while to hit production.

AllanOricil · 2020-08-06T00:13:38Z

@AllanOricil it means that we will not fix it in current production code, but in the upcoming release only, which might take a while to hit production.

Thanks for clarifying it @caridy
I understood it wrong. Sorry for that.

iarecuezero · 2020-08-31T19:20:10Z

Can this issue also occur when a custom LWC component uses emp-api and and an Aura component uses emp-api where the Aura component is in a managed package?

AllanOricil · 2020-09-03T08:06:16Z

Can this issue also occur when a custom LWC component uses emp-api and and an Aura component uses emp-api where the Aura component is in a managed package?

@iarecuezero This can happen if you place both components on the same page.

fredgaume · 2020-10-29T08:36:59Z

@caridy Hi there. Seems that we still have the issue. Could you confirm that it has not been fixed in the Winter release? Or am I wrong?

pazhukh · 2021-04-13T07:45:40Z

Can this issue also occur when a custom LWC component uses emp-api and and an Aura component uses emp-api where the Aura component is in a managed package?

Looks like I have the same problem :(

AllanOricil · 2021-04-13T11:03:33Z

Can this issue also occur when a custom LWC component uses emp-api and and an Aura component uses emp-api where the Aura component is in a managed package?

Looks like I have the same problem :(

If your Aura component is simple, migrate it to LWC. Just don't mix both "frameworks" and you will never have this problem

KeithClarke · 2021-12-24T11:02:30Z

Just added a wrapping Aura component to implement lightning:isUrlAddressable for navigation purposes and no longer receiving a platform event in an LWC in the same managed package namespace located in a different page that was previously working. No subscription in the Aura component.

@AllanOricil, I think there may be no work-around for this case?

AllanOricil · 2021-12-24T11:12:21Z

No subsc
@KeithClarke
Don't mix aura with lwc in the same lighting page

KeithClarke · 2021-12-24T11:21:39Z

Hi @AllanOricil,

My point was that there is no way to use the documented lightning:isUrlAddressable technique without Aura as well and LWC.

But came back here to delete my comment as this is now all working correctly in a new scratch org so my problem was not this and the Aura/LWC mix is working for me. Sorry for the noise.

berginrp · 2022-07-24T06:33:29Z

I have a similar problem.
My lwc is wrapped by an aura component, and is placed within an existing VF page in Service Cloud console.

I'm trying to subscribe to platform event using empApi in my lwc component, but its not subscribing.
When I put the exact thing in a lwc within a Lightning page, the subscription to the event works.

My requirement is to take action based on the event received.

With my usecase, I have to put this lwc into an VF page and have to use aura component to achieve this.
Is there any workaround? any help in this regard is appreciated. thank you!

ChuckJonas · 2025-03-08T05:22:42Z

Can this issue also occur when a custom LWC component uses emp-api and and an Aura component uses emp-api where the Aura component is in a managed package?

If your Aura component is simple, migrate it to LWC. Just don't mix both "frameworks" and you will never have this problem

@AllanOricil That's not how Salesforce works... If the Aura component is part of a managed package, you obviously cannot migrate it...

pmdartus added the External: Lightning Web Security / Locker Categorizes issue or PR as related to LWS or Lightning Locker. label May 27, 2020

AllanOricil closed this as not planned Won't fix, can't repro, duplicate, stale Mar 3, 2023

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LWC EmpApi does not work when there is an Aura component using EmpApi #1618

LWC EmpApi does not work when there is an Aura component using EmpApi #1618

AllanOricil commented Nov 16, 2019 •

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LWC EmpApi does not work when there is an Aura component using EmpApi #1618

LWC EmpApi does not work when there is an Aura component using EmpApi #1618

Comments

AllanOricil commented Nov 16, 2019 • edited Loading

Description

Steps to Reproduce

Expected Results

Actual Results

AllanOricil commented Nov 16, 2019

miteshmsharma commented Nov 17, 2019 via email

AllanOricil commented Nov 17, 2019 • edited Loading

joeferraro commented Apr 6, 2020 • edited Loading

caridy commented Apr 6, 2020

joeferraro commented Apr 8, 2020

caridy commented Apr 8, 2020

manuel-jasso commented Apr 9, 2020

vc4u commented May 30, 2020 • edited Loading

AllanOricil commented May 30, 2020

arneper commented May 31, 2020

seksenov commented Jun 1, 2020

arneper commented Jun 1, 2020

manuel-jasso commented Jul 9, 2020

AllanOricil commented Jul 9, 2020 • edited Loading

manuel-jasso commented Jul 9, 2020

AllanOricil commented Jul 10, 2020

arcadeteddy commented Jul 21, 2020 • edited Loading

AllanOricil commented Jul 21, 2020

gyadav4 commented Aug 4, 2020

arcadeteddy commented Aug 5, 2020

AllanOricil commented Aug 5, 2020

caridy commented Aug 5, 2020

AllanOricil commented Aug 6, 2020 • edited Loading

iarecuezero commented Aug 31, 2020

AllanOricil commented Sep 3, 2020

fredgaume commented Oct 29, 2020

pazhukh commented Apr 13, 2021

AllanOricil commented Apr 13, 2021

KeithClarke commented Dec 24, 2021 • edited Loading

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