### Use cases:

* List Begin of the insertionfiles that belong to aEnd of the insertion work Begin of the insertionpackageEnd of the insertion Begin of the deletion packagesEnd of the deletion in a separate "Files" Begin of the insertiontab.End of the insertion Begin of the deletion tab of a work package.End of the deletion
* The tab lists all conventional work package attachments in one section, and
* Begin of the insertionin another section it listsEnd of the insertion all Begin of the insertionlinksEnd of the insertion Begin of the deletion "file links"End of the deletion to Begin of the insertionrelated files that reside within an external _file storage_. We call these links _file links._ In the first implementationEnd of the insertion a Begin of the insertion_file storage_End of the insertion Begin of the deletion "file storage" (A specific Nextcloud instanceEnd of the deletion is Begin of the deletion suchEnd of the deletion a Begin of the insertionspecific Nextcloud instance.End of the insertion Begin of the deletion "file storage")End of the deletion
* The tab shows a number indicating the amount of files (attachments + file links) in the tab handle, similar to the "Watchers" tab.
* Begin of the insertionOn each listed _file link_
* A click on theEnd of the insertion Begin of the deletion Quick access buttons or menu entries perEnd of the deletion file Begin of the insertionname opens the file (opens file in Nextcloud file editor/viewer)End of the insertion Begin of the deletion forEnd of the deletion
* Begin of the insertionA _download_ button will startEnd of the insertion downloading file to hard drive (can be deactivated per storage in admin settings)
* Begin of the insertionA _folder_ button will open theEnd of the insertion Begin of the deletion OpenEnd of the deletion file Begin of the deletion (opens fileEnd of the deletion in Begin of the deletion Nextcloud file editor/viewer)
* Show file inEnd of the deletion its location (opens the directory in Nextcloud where the file is located)
* Delete file link Begin of the insertion(removes the link but does not delete the file)End of the insertion
* Show meta information per file
* File type _(PDF, JPG,_ etc.)
* File size (_2.8 MB_)
* Last modified Begin of the insertiontime stamp
* Last modifiedEnd of the insertion by (name) if available through Nextcloud API
* Created by (name) if available through Nextcloud API
* Owner (name) if available through Nextcloud API
* Path if feasible (a shared file can have multiple paths)
* Create a link between a work package and an existing file in Nextcloud.
* Clicking a button in the "Files" tab will show a file picker with the Nextcloud file structure for that user Begin of the insertion(Keep in mind that everyEnd of the insertion Begin of the deletion (EveryEnd of the deletion Nextcloud user has a different file structure)
* To achieve this, the current OpenProject user will need to request authorization from Nextcloud via OAuth, so that OpenProject consequently can make personalized API requests to Nextcloud.
* Upload a file from within a work package in Begin of the insertionOpenProject
* Chose aEnd of the insertion Begin of the deletion OpenProject, choseEnd of the deletion location in Begin of the insertionNextcloud via a _location picker_
* SaveEnd of the insertion Begin of the deletion Nextcloud, saveEnd of the deletion the file in Begin of the insertionNextcloudEnd of the insertion Begin of the deletion Nextcloud, create linkEnd of the deletion
* Begin of the insertionCreate a _file link_ between the work package 
* End of the insertion **Out of scope:** Upload of entire directories, as normal Form uploads do not allow this. So only the upload of individual files will be Begin of the insertionsupported in the first version.End of the insertion Begin of the deletion supported.End of the deletion
* Delete Begin of the insertion_file links_End of the insertion Begin of the deletion file linksEnd of the deletion from a work package (without deleting it in Nextcloud).

### Implementation blocks:

* Files tab in for work packages.
* OAuth reverse direction (authorize OpenProject users in Nextcloud) with refreshing mechanism.
* File picker for selecting link targets (files and directories). Queries Nextcloud with the user's access token Begin of the insertion(probablyEnd of the insertion via Begin of the insertionWebDAV).End of the insertion Begin of the deletion WEBDAV.End of the deletion
* Location picker for upload targets (a target is always a directory). Queries Nextcloud with the user's access token Begin of the insertion(probablyEnd of the insertion via Begin of the insertionWebDAV).End of the insertion Begin of the deletion WEBDAV.End of the deletion
* If possible, direct upload of files to Nextcloud without tunneling through OpenProject server. This requires some sort of one-time upload tokens, which can get exposed to the Begin of the insertionOpenProjectEnd of the insertion frontend. Fallback could be tunneling all uploaded files through OpenProject.
* Remove file links from OpenProject when files get deleted in Nextcloud (either some sort of callback triggered by Nextcloud or through Begin of the insertionpolling when user opens the _Files_ tab).End of the insertion Begin of the deletion some periodic polling).End of the deletion

### Begin of the insertionImplementation decisions:End of the insertion Begin of the deletion Open technical questions:End of the deletion

* Begin of the insertionTheEnd of the insertion Begin of the deletion WhatEnd of the deletion file name Begin of the deletion doEnd of the deletion we Begin of the insertionpresent in OpenProject is the name of the file that the file's owner sees. Apparently inEnd of the insertion Begin of the deletion show? InEnd of the deletion Nextcloud a file Begin of the deletion apparentlyEnd of the deletion can have multiple names and Begin of the insertionpaths every time a file gets shared. To have a "canonical" name for all OpenProject users we will always showEnd of the insertion Begin of the deletion paths. It is not clear which isEnd of the deletion the Begin of the insertionfile name that the file's owner sees.End of the insertion Begin of the deletion _canonical_ name. Needs to get clarified soon.End of the deletion
* Begin of the insertionOpenProject updatesEnd of the insertion Begin of the deletion How do we know when to updateEnd of the deletion the Begin of the insertion"cached"End of the insertion Begin of the deletion cachedEnd of the deletion file name in Begin of the insertionOpenProject when a user open the _Files_ tab.End of the insertion Begin of the deletion OpenProject?End of the deletion

### Out of scope:

* Syncing of access rights to the files in Nextcloud according to the roles and privileges of members in a OpenProject project. This would require two things
* OpenProject is somehow owning directories and files and can share them with (read or read/write permissions with other Nextcloud users).
* All users and groups are in sync between OpenProject and Nextcloud. It seems a good idea to use LDAP as the single source of truth. However, the timing, when all users and groups have completed syncing with both systems, OpenProject and Nextcloud, does not seem trivial.
* Linking between a OpenProject project (instead of work packages) and files in Nextcloud. That is feasible and intended to built in a later stage. The outlook could be a possible replacement for the current "Documents" module.

### Wire frames (to sketch the idea. Not final design)

Listing attachments and file links in a separate :work package tab

<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/29264/content"></div></figure>

Linked file&#39;s meta data

<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/29263/content"></div></figure>

Uploading files via drag&#39;n drop (early concept sketch)

<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/29265/content"></div></figure>

File picker

<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/29266/content"></div></figure>