Display Binary as download link

RE: Display Binary as download link

Stefan Helzle — Tue, 18 Mar 2025 20:30:22 GMT

Like Mike Schmitt already said, if you want to download a file through Appian, the file has to be stored in Appian first.

If that is a problem, store the files in a temporary folder and clean that up in a certain interval.

RE: Display Binary as download link

sirishar0001 — Tue, 18 Mar 2025 20:28:06 GMT

Actual document resides in the external system. We cannot acquire a URL unfortunately. We have a getFile integration call that gives us the byte Array corresponding to the document contents. We need a way to display that in Appian UI (preferably all this happens when you click a link on document name :()

RE: Display Binary as download link

Mike Schmitt — Tue, 18 Mar 2025 18:04:07 GMT

[quote userid="67455" url="~/discussions/f/integrations/38721/display-binary-as-download-link/146337"]if we get back the binary of the document?[/quote]

Can you specify what this means? For instance what exactly do you mean by "get back"? Where is the actual document going to be residing when you want it downloaded? If it's only going to be located on the external system (since you say you're not allowed to temporarily send it to the Appian filesystem), you would need a way to acquire a URL to the document download from within that external system (assuming that's even possible), and transfer said URL into Appian, which you could then display in Appian via a SafeLink, for example.

RE: Display Binary as download link

sirishar0001 — Tue, 18 Mar 2025 16:44:27 GMT

Ok if we cannot use Document Download Link is there another way to provide a document download from external system if we get back the binary of the document?

RE: Display Binary as download link

Mike Schmitt — Tue, 18 Mar 2025 16:25:24 GMT

Then your requirements seem to be in conflict with each other - you will need to decide which path you want to take, because you can not do both things at once.

If you really can't store the document in Appian (even temporarily), then you won't be able to use Document Download Link at all, since it is only for documents stored in the Appian filesystem. The best you'll be able to do is have Appian display a valid URL to download the document from its original (external) location.

RE: Display Binary as download link

sirishar0001 — Tue, 18 Mar 2025 16:15:02 GMT

Our use case is documents are stored in another content management system and when we view a record (like vendor/customer record) we only need to show links to the documents and clicking on the link should download the document from the external content management system. We cannot store document in Appian and delete since we do not know how long we need it for.

RE: Display Binary as download link

Mike Schmitt — Tue, 18 Mar 2025 16:03:59 GMT

Note if you have a valid Appian Document ID, the document is already stored within the Appian filesystem, and using todocument() on it is irrelevant. Also there is no need to wrap the document ID in todocument() for use in a!documentDownloadLink, all that's required is a valid ID.

If you're getting an "ID not found" error, your issue is something deeper, which you will need to address. And there is no way to provide a download link without making a valid copy into Appian - if you don't want the file to persist, I suggest incorporating a timer in your process that handles the copy, which auto-deletes the downloaded document after some amount of time has passed (after which you can assume the user has had plenty of time to download a copy on-form).