How can I list content of sharded folder that has not mounted yet?

[23W]

How can I list content of sharded folder that has not been mounted yet?

[Greg-DB · Accepted solution]

The Dropbox API functionality for listing folders is generally only meant for mounted content, but you can technically list the contents of an unmounted folder by calling /2/files/list_folder with the 'preview_url' (e.g., from the shared folder metadata) as the 'shared_link.url' parameter, like:

curl -X POST https://api.dropboxapi.com/2/files/list_folder \
    --header "Authorization: Bearer <ACCESS_TOKEN>" \
    --header "Content-Type: application/json" \
    --data "{\"path\": \"\", \"shared_link\": {\"url\": \"<PREVIEW_URL>\"}}"

[23W]

@Greg-DB, thank you. It really works.

But next question appears: if such folder contains sub-folders, how to browse them?

"/2/files/lits_folder" returns list of sub-folders with theirs Ids. Direct attempt to use one of them with "/2/files/lits_folder" returns error "path not found". If i try to use "/2/sharing/get_folder_metadata" with sub-folder's id, i receive error "invalid id".
All those Ids have prefix like "id:_XXXXXX".

[Greg-DB]

The "id" values for the listed items, starting file "id:", is the "file ID", which is different than a "shared folder ID", so you can't use that for /2/sharing/get_folder_metadata, 

You can use the "path" parameter to list a subfolder when accessing a shared link via /2/files/list_folder though. That would look like:

curl -X POST https://api.dropboxapi.com/2/files/list_folder \
    --header "Authorization: Bearer <ACCESS_TOKEN>" \
    --header "Content-Type: application/json" \
    --data "{\"path\": \"/subfoldername\", \"shared_link\": {\"url\": \"<PREVIEW_URL>\"}}"

[23W]

@Greg-DB 
Thank you. So if I for example have following structure in shared folder:

• Shared Folder
  • Sub Folder 1
    • Sub Folder 2
    • file 1 in Sub Folder 1
    • file 2 in Sub Folder 1
  • file 1 in Shared Foder

And I want to browse contenten of "Sub Folder 1", I have to use "/2/files/list_folder" endpoint with "shared_link" of "Shared Folder" and "path" equal to "/Sub Folder 1".

If I want to do the same but for "Sub Folder 2", "path" parameter should be "/Sub Folder1/Sub Folder 2". Am I right?

It is not convenient way as for me because in my application it's possible that I know only "id" of "Sub Folder 2" and "shared id" of "Shared Folder", so I don't know exact relative path from "Shared Folder" to "Sub Folder 2". 😞

From other side, I've found that I can use "namespace" of "Shared Folder" to browse it content and use "id"s of files and folder directly as "path" parameter, without building "shared_link" url from PreviewUrl of "Shared Folder". As soon as I'm using your C# SDK, I build client via following method:

client = client.WithPathRoot(new Dropbox.Api.Common.PathRoot.NamespaceId(sharedFolder.SharedFolderId));

And looks like it works.
So can I use this method to work with Shared Folders that are NOT mounted to the user's storage? "Work" in this case means browse, upload, download, delete files, create sub folders and so on.

As I understand from documentation this method is suitable for Team Folders also, correct?

[Greg-DB]

For the first way, note that you can determine the relative nested path from the responses from /2/files/list_folder. For example:

• call /2/files/list_folder with the 'shared_link', and 'path:""' => the result shows the "Sub Folder 1"
• call /2/files/list_folder with the 'shared_link', and 'path:"/Sub Folder 1"' => the result shows the "Sub Folder 2"
•  call /2/files/list_folder with the 'shared_link', and 'path:"/Sub Folder 1/Sub Folder 2"' => the result shows the contents of "Sub Folder 2".

And yes, if that other way works for your use case, that's fine too. You can find more information on that functionality in the Namespace Guide.

[23W]

@Greg-DB 
Thank you, using Namesapces works fine. With the same code I can now browse both team folders and shared but not mounted folders. If such folder is editable I can create\delete\rename subfolders, I can download\delete and rename files of the folder and from any deep subfolder.

But there is one strange issue. I can create\upload new file to team folder but if I try to create\upload file to shared folder (not mounted to account space), I receive 503 error.
Example of such request headers (body is file content):

POST /2/files/upload HTTP/1.1
Authorization: Bearer XXXXXXXXXXXXXXXXXXXXXXXXXXX
User-Agent: MindManager/OfficialDropboxDotNetSDKv2/4.0.0.0
Dropbox-Api-Path-Root: {".tag":"namespace_id","namespace_id":"6428536912"}
Dropbox-API-Arg: {"path":"id:ZRivQP0OLRAAAAAAAAAALA","mode":{".tag":"overwrite"},"autorename":false,"mute":false,"strict_conflict":false}
Content-Type: application/octet-stream
Host: content.dropboxapi.com
Content-Length: 38669
Expect: 100-continue

And server's responce on it:

HTTP/1.1 503 Service Unavailable
Server: nginx
Date: Wed, 09 Oct 2019 16:29:49 GMT
Content-Type: text/plain; charset=utf-8
Transfer-Encoding: chunked
Connection: keep-alive
Content-Security-Policy: sandbox allow-forms allow-scripts
X-Dropbox-Request-Id: ec718807718c7913cbdd755f9e36c08c
X-Robots-Tag: noindex, nofollow, noimageindex

Could you help me find the bug? Because as for me, it looks like issue on server side or bug in C# Dropbox SDK.

[Greg-DB]

Attempting to upload to an unmounted shared folder will fail. The shared folder needs to be mounted for an app to make changes in it.

We should return a better error message in this case though. I'll ask the team to update the API to return a useful error when this is attempted. Thanks!

[23W]

@Greg-DB 
Thanks, it's a bit disappointing but expected. Can you say, only upload operation is forbidden for such type of shared folder or I should avoid other modification operation like renaming, creating\deleting sub-folders? Currently they work fine, can I use them in production?

[Greg-DB]

Some other kinds of changes may work, but I can't guarantee if that's officially supported. I'll ask the team to confirm this and document it explicitly.