Custom App - download of multiple files not working in Teams 2.0 desktop app

[pFritsch]

Hello,

we have a working custom app which users can use to navigate files in a storage solution. It worked perfectly in the old Teams, however since the "New Teams" was published we got a problem regarding downloading files. Downloading a single file is working as intended, however downloading multiple files with one single click runs into nothing. The download is not started and our client-code also doesn't run into any error - it seems like it works as intended even while debugging and stepping over each line of code. However, the download doesn't get started. 

It is working in the web version of Teams 2.0 if the user accepts the pop-up which asks if multiple downloads should be allowed (this is a one-time thing and is prompted by the browser). Therefore, our guess is that the Teams 2.0 desktop client would need to prompt for this security setting too, but doesn't and therefore "blocks" all downloads.

Our download is realized through creating an iframe, setting its source to the download url and appending it to the document body. We also tried to use this npm package, but it didn't help with our problem: https://www.npmjs.com/package/file-saver

Hope you can help us.

Best Regards

Patrick

[#2]

@pFritsch - Could you please provide any sample code repo or document you followed, so that we can repro this at our end? If you have the app deployed, please do share the manifest, it would be super helpful. Thanks!

[#3]

@Prasad_Das-MSFT We have created a minimal example for you to test via the VSCode Microsoft Teams Toolkit. It works in the browser as the popup for multiple downloads appear, but just like our real app it fails when hosted in the desktop client. 

You can check it out here: https://github.com/corner4-Information-Technology-GmbH/teams-tab-example

[#4]

@pFritsch - Thanks for sharing this. We will test this and will get back to you.

[#5]

@pFritsch - Although we ran into some certification issue and not able to repro, we have raised a bug for this issue. We will inform you once we get any further update from engineering team.

Thanks, 

Prasad Das

------------------------------------------------------------------------------------------ 

If the response is helpful, please click "**Mark as Best Response**" and like it. You can share your feedback via Microsoft Teams Developer Feedback link. Click here to escalate.

[#6]

@Prasad_Das-MSFT - Thanks for raising a bug - sorry to here you were not able to repo. However, all custom code needed is in the teams-tab-example/src/views/hello.html file , so it should at least be easier to see whats going wrong. Im eager waiting to hearing back from the engineering team.

[#7]

Any update on this matter?

[#8]

@pFritsch - Engineering team is working on the fix. Currently there is no ETA to share. However, we will inform you once we hear any update. Thanks!

[#9]

@Prasad_Das-MSFT - Hi! It has now been over a month since the last response. Is there any update on this matter? This is still an ongoing issue which affects our product.

[#10]

@Prasad_Das-MSFT Hi, this is still an issue! Any update on this matter?