61 lines
2.9 KiB
Markdown
61 lines
2.9 KiB
Markdown
FoodsoftPrinter
|
|
=================
|
|
|
|
This plugin adds a printer queue to allow mebers to print PDF with one click.
|
|
Usually a mini computer with a printer at a room in the foodcoop will wait for
|
|
new printer jobs and prints them.
|
|
|
|
This plugin is not enabled by default. To install it, add uncomment the
|
|
corresponding line in the `Gemfile`, or add:
|
|
|
|
```Gemfile
|
|
gem 'foodsoft_printer', path: 'plugins/foodsoft_printer'
|
|
```
|
|
|
|
This plugin introduces the foodcoop config option `printer_token`, which takes
|
|
a random string for authentication at the endpoint. Additionally a set of
|
|
PDF files can be selected, which will be generated when a print is triggered.
|
|
|
|
The communication with the printer client happens via two endpoints, which both
|
|
require the `printer_token` as `Bearer` token in the `Authorization` header.
|
|
* `/:foodcoop/printer/socket`: main WebSocket communication
|
|
* `/:foodcoop/printer/:id`: HTTP GET for documents
|
|
|
|
The main communication happens via JSON messages via an WebSocket connection,
|
|
which sends an array of docuement ids to the client, which need to be printed.
|
|
Addionally the docuemnt can be downloaded as PDF via a separate endpoint.
|
|
The client can updated the status of the documents by sending an object with
|
|
the following keys to the server:
|
|
* `id` (NBR, REQUIRED): id of the document, which should be updated
|
|
* `state` (ENUM): the current sate of the printing progress.
|
|
* `message` (STR, REQUIRES `state`): detailed description of the current state
|
|
(e.g. download progress)
|
|
* `finish` (BOOL): when set to `true` the job will be marked as done
|
|
|
|
The following values are valid for the `state` property:
|
|
* `queued`: the document is not yet ready for printing
|
|
* `ready`: the document is ready to be downloaded
|
|
* `downloading`: transfer of the document is in progress
|
|
* `pending`: download completed, waiting for the printer
|
|
* `held`: e.g., for "PIN printing"
|
|
* `processing`: printing is in progress
|
|
* `stopped`: out of paper, etc.)
|
|
* `cancelled`: the user stopped the action
|
|
* `aborted`: the printer stopped the action
|
|
* `completed`: print was successful
|
|
|
|
**Example**:
|
|
A server sending `{"unfinished_jobs":[12,16]}` via WebSocket indicates that the
|
|
two documents `12` and `16` are ready for printing. The client will request the
|
|
first document from `/foodcoop/printer/12` and send it to the printer. The
|
|
status can be updated by sending `{"id":12,"state":"pending"}` via WebSocket to
|
|
the server. Sending `{"id":12,"state":"completed","finish":true}` as soon as
|
|
when the printing succeded will mark the job done.
|
|
|
|
To use this plugin the webserver must support WebSockets. The current
|
|
implementation uses socket hijack, which is not supported by `thin`. `puma`
|
|
supports that, but might lead to other problems, since it's not well tested
|
|
in combination with foodsoft. Please be careful when switching the webserver!
|
|
|
|
This plugin is part of the foodsoft package and uses the AGPL-3 license (see
|
|
foodsoft's LICENSE for the full license text).
|