Development
This section describes the steps you need to take to start development on Paperless-ngx.
Check out the source from GitHub. The repository is organized in the following way:
main
always represents the latest release and will only see changes when a new release is made.dev
contains the code that will be in the next release.feature-X
contains bigger changes that will be in some release, but not necessarily the next one.
When making functional changes to Paperless-ngx, always make your changes
on the dev
branch.
Apart from that, the folder structure is as follows:
docs/
- Documentation.src-ui/
- Code of the front end.src/
- Code of the back end.scripts/
- Various scripts that help with different parts of development.docker/
- Files required to build the docker image.
Contributing to Paperless-ngx
Maybe you've been using Paperless-ngx for a while and want to add a feature or two, or maybe you've come across a bug that you have some ideas how to solve. The beauty of open source software is that you can see what's wrong and help to get it fixed for everyone!
Before contributing please review our code of conduct and other important information in the contributing guidelines.
Code formatting with pre-commit hooks
To ensure a consistent style and formatting across the project source,
the project utilizes Git pre-commit
hooks to perform some formatting and linting before a commit is allowed.
That way, everyone uses the same style and some common issues can be caught
early on.
Once installed, hooks will run when you commit. If the formatting isn't
quite right or a linter catches something, the commit will be rejected.
You'll need to look at the output and fix the issue. Some hooks, such
as the Python linting and formatting tool ruff
, will format failing
files, so all you need to do is git add
those files again
and retry your commit.
General setup
After you forked and cloned the code from GitHub you need to perform a first-time setup.
Note
Every command is executed directly from the root folder of the project unless specified otherwise.
-
Install prerequisites + pipenv as mentioned in Bare metal route.
-
Copy
paperless.conf.example
topaperless.conf
and enable debug mode within the file viaPAPERLESS_DEBUG=true
. -
Create
consume
andmedia
directories: -
Install the Python dependencies:
Note
Using a virtual environment is highly recommended. You can spawn one via
pipenv shell
. -
Install pre-commit hooks:
-
Apply migrations and create a superuser for your development instance:
-
You can now either ...
-
install redis or
-
use the included
scripts/start_services.sh
to use docker to fire up a redis instance (and some other services such as tika, gotenberg and a database server) or -
spin up a bare redis container
-
-
Continue with either back-end or front-end development – or both :-).
Back end development
The back end is a Django application. PyCharm as well as Visual Studio Code work well for development, but you can use whatever you want.
Configure the IDE to use the src/
-folder as the base source folder.
Configure the following launch configurations in your IDE:
python3 manage.py runserver
python3 manage.py document_consumer
celery --app paperless worker -l DEBUG
(or any other log level)
To start them all:
# src/
$ python3 manage.py runserver & \
python3 manage.py document_consumer & \
celery --app paperless worker -l DEBUG
You might need the front end to test your back end code. This assumes that you have AngularJS installed on your system. Go to the Front end development section for further details. To build the front end once use this command:
Testing
- Run
pytest
in thesrc/
directory to execute all tests. This also generates a HTML coverage report. When runnings test,paperless.conf
is loaded as well. However, the tests rely on the default configuration. This is not ideal. But for now, make sure no settings except for DEBUG are overridden when testing.
Note
The line length rule E501 is generally useful for getting multiple
source files next to each other on the screen. However, in some
cases, its just not possible to make some lines fit, especially
complicated IF cases. Append # noqa: E501
to disable this check
for certain lines.
Front end development
The front end is built using AngularJS. In order to get started, you need Node.js (version 14.15+) and
npm
.
Note
The following commands are all performed in the src-ui
-directory. You will need a running back end (including an active session) to connect to the back end API. To spin it up refer to the commands under the section above.
-
Install the Angular CLI. You might need sudo privileges to perform this command:
-
Make sure that it's on your path.
-
Install all necessary modules:
-
You can launch a development server by running:
This will automatically update whenever you save. However, in-place compilation might fail on syntax errors, in which case you need to restart it.
By default, the development server is available on
http://localhost:4200/
and is configured to access the API athttp://localhost:8000/api/
, which is the default of the backend. If you enabledDEBUG
on the back end, several security overrides for allowed hosts, CORS and X-Frame-Options are in place so that the front end behaves exactly as in production.
Testing and code style
The front end code (.ts, .html, .scss) use prettier
for code
formatting via the Git pre-commit
hooks which run automatically on
commit. See above for installation instructions. You can also run this via the CLI with a
command such as
Front end testing uses Jest and Playwright. Unit tests and e2e tests, respectively, can be run non-interactively with:
Playwright also includes a UI which can be run with:
Building the frontend
In order to build the front end and serve it as part of Django, execute:
This will build the front end and put it in a location from which the Django server will serve it as static content. This way, you can verify that authentication is working.
Localization
Paperless-ngx is available in many different languages. Since Paperless-ngx consists both of a Django application and an AngularJS front end, both these parts have to be translated separately.
Front end localization
- The AngularJS front end does localization according to the Angular documentation.
- The source language of the project is "en_US".
- The source strings end up in the file
src-ui/messages.xlf
. - The translated strings need to be placed in the
src-ui/src/locale/
folder. - In order to extract added or changed strings from the source files,
call
ng extract-i18n
.
Adding new languages requires adding the translated files in the
src-ui/src/locale/
folder and adjusting a couple files.
-
Adjust
src-ui/angular.json
: -
Add the language to the
LANGUAGE_OPTIONS
array insrc-ui/src/app/services/settings.service.ts
: -
Import and register the Angular data for this locale in
src-ui/src/app/app.module.ts
:
Back end localization
A majority of the strings that appear in the back end appear only when the admin is used. However, some of these are still shown on the front end (such as error messages).
- The django application does localization according to the Django documentation.
- The source language of the project is "en_US".
- Localization files end up in the folder
src/locale/
. - In order to extract strings from the application, call
python3 manage.py makemessages -l en_US
. This is important after making changes to translatable strings. - The message files need to be compiled for them to show up in the
application. Call
python3 manage.py compilemessages
to do this. The generated files don't get committed into git, since these are derived artifacts. The build pipeline takes care of executing this command.
Adding new languages requires adding the translated files in the
src/locale/
-folder and adjusting the file
src/paperless/settings.py
to include the new language:
LANGUAGES = [
("en-us", _("English (US)")),
("en-gb", _("English (GB)")),
("de", _("German")),
("nl-nl", _("Dutch")),
("fr", _("French")),
("pt-br", _("Portuguese (Brazil)")),
# Add language here.
]
Building the documentation
The documentation is built using material-mkdocs, see their documentation. If you want to build the documentation locally, this is how you do it:
-
Have an active pipenv shell (
pipenv shell
) and install Python dependencies: -
Build the documentation
alternatively...
-
Serve the documentation. This will spin up a copy of the documentation at http://127.0.0.1:8000 that will automatically refresh every time you change something.
Building the Docker image
The docker image is primarily built by the GitHub actions workflow, but it can be faster when developing to build and tag an image locally.
Make sure you have the docker-buildx
package installed. Building the image works as with any image:
Extending Paperless-ngx
Paperless-ngx does not have any fancy plugin systems and will probably never have. However, some parts of the application have been designed to allow easy integration of additional features without any modification to the base code.
Making custom parsers
Paperless-ngx uses parsers to add documents. A parser is responsible for:
- Retrieving the content from the original
- Creating a thumbnail
- optional: Retrieving a created date from the original
- optional: Creating an archived document from the original
Custom parsers can be added to Paperless-ngx to support more file types. In order to do that, you need to write the parser itself and announce its existence to Paperless-ngx.
The parser itself must extend documents.parsers.DocumentParser
and
must implement the methods parse
and get_thumbnail
. You can provide
your own implementation to get_date
if you don't want to rely on
Paperless-ngx' default date guessing mechanisms.
class MyCustomParser(DocumentParser):
def parse(self, document_path, mime_type):
# This method does not return anything. Rather, you should assign
# whatever you got from the document to the following fields:
# The content of the document.
self.text = "content"
# Optional: path to a PDF document that you created from the original.
self.archive_path = os.path.join(self.tempdir, "archived.pdf")
# Optional: "created" date of the document.
self.date = get_created_from_metadata(document_path)
def get_thumbnail(self, document_path, mime_type):
# This should return the path to a thumbnail you created for this
# document.
return os.path.join(self.tempdir, "thumb.webp")
If you encounter any issues during parsing, raise a
documents.parsers.ParseError
.
The self.tempdir
directory is a temporary directory that is guaranteed
to be empty and removed after consumption finished. You can use that
directory to store any intermediate files and also use it to store the
thumbnail / archived document.
After that, you need to announce your parser to Paperless-ngx. You need to
connect a handler to the document_consumer_declaration
signal. Have a
look in the file src/paperless_tesseract/apps.py
on how that's done.
The handler is a method that returns information about your parser:
def myparser_consumer_declaration(sender, **kwargs):
return {
"parser": MyCustomParser,
"weight": 0,
"mime_types": {
"application/pdf": ".pdf",
"image/jpeg": ".jpg",
}
}
parser
is a reference to a class that extendsDocumentParser
.weight
is used whenever two or more parsers are able to parse a file: The parser with the higher weight wins. This can be used to override the parsers provided by Paperless-ngx.mime_types
is a dictionary. The keys are the mime types your parser supports and the value is the default file extension that Paperless-ngx should use when storing files and serving them for download. We could guess that from the file extensions, but some mime types have many extensions associated with them and the Python methods responsible for guessing the extension do not always return the same value.