API - receive json data and write to file

[nekton]

Trying to figure out how to receive data from external source, write it into a file and process with an external script. First time approaching something like that, I would deeply appreciate some guidance. This is how I see it at present:

• Step One - transport to Nextcloud

  • Establish API endpoint:
    I have played with GET requests using curl via OCS API as user but no clue how to access a specific file to write? https://docs.nextcloud.com/server/latest/developer_manual/client_apis/OCS/ocs-api-overview.html#direct-download
    Do I need to create a separate app to receive data using REST by creating routes in PHP? REST APIs — Nextcloud latest Developer Manual latest documentation or should I follow the JavaScript way with axios? JavaScript APIs — Nextcloud latest Developer Manual latest documentation
  • POST/PUT JSON (or x-www-form-urlencoded?) data with custom header options to URL - do I need to authenticate as a user like with OSC API or can I generate a dedicated authentication token? Could I use PUT in order to append an existing file (.csv) rather than POST to create a new file?

• Step Two - process the file

  • Upon modifying/creating the file, trigger an external script via Flow https://github.com/nextcloud/workflow_script - I have written the python code I run locally on .csv. Don’t know how to reference my main.py file (presumably to be placed on the same machine) - as a bash script typed into the ‘Run script’ input field, providing the absolute path?
  • Output a spreadsheet file - since this is an external script I can write to the local Nextcloud path and the Files app will acknowledge it? If so, is that a bad practice?

[Larry_Boyd]

You can actually combine step 1 and 2, there is no need to load a file first and then call some script to process it. You can just send the data to a script that processes it.

Develop for Nextcloud – Nextcloud

What you do is you create a route (appinfo/routes.php) which calls a php function in a controller (lib/Controller/Whatever.php) – Tutorial — Nextcloud latest Developer Manual latest documentation

The data you provide via GET/POST/PUT will be provided to the function in the controller as parameters, which you can then process. You can add flags to your function based on the kind of security / access control you want, which by default will require an authenticated administrator, but, for example, you can flag @NoAdminRequired to change that to ANY authenticated user, or @PublicPage to open the script to the public and/or perform your own security checks, etc.

For example, postdata=“data=something&username=jimmy” → public function myfunction(string $data, string $username){…}
The variables in the postdata will be available via corresponding variables in the controller’s function.

You can also upload a file to your controller and access it directly rather than having it broken up as parameters;
https://docs.nextcloud.com/server/latest/developer_manual/basics/controllers.html#reading-headers-files-cookies-and-environment-variables