File Access Endpoint implemented by your system allows rollApp to download the file for editing by the user. And later, when the user is done with edits, upload updated file back to your system.
How rollApp downloads a file
Before the application is started we will download the file into the application container on one of our cloud servers. To do that we will make a GET request to the File Access Endpoint URL you've given.
GET https://www.example.com/case/123/attachments/overview.docx
...
X-Access-Token: 1234567890
X-Access-Token header will have the access_token value you've given us, when initiating file editing using rollMyFile.editFile().
This request can be redirected by your system to another URL using 302 Moved Temporarily.
How rollApp uploads a file
When the file is saved by the application, rollApp will upload the updated file to the File Access Endpoint. This happens, when users saves the file in the application (e.g. by clicking File->Save, clicking the Save icon in the toolbar) or the application initiates saving of the file (e.g. through autosave) itself.
The file is uploaded using multipart POST request. X-Access-Token header will have the access_token value you've given us, when initiating file editing using rollMyFile.editFile().
POST https://www.example.com/case/123/attachments/overview.docx
...
X-Access-Token: 1234567890
Content-Type: multipart/form-data; boundary=----------------------------1234567890ab
------------------------------1234567890ab
Content-Disposition: form-data; name="file"; filename="overview.docx"
Content-Type: application/octet-stream
<file content>
------------------------------1234567890ab
File can be saved multiple times
The user or the application can save the file multiple times during file editing session. Each file saving operation will result in upload of the updated file to the File Access Endpoint.