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RPC (Remote Procedure Call) is a pretty old network protocol used to call functions on another system or web server through HTTP POST requests. It has been created decades ago and is one of the predecessor of modern Web API protocols (REST, GraphQL, etc.).

While it is a bit outdated now, there is still use-cases were XML-RPC or JSON-RPC server must be implemented. Django-modern-rpc will help you setup such a server as part of your Django project.

Getting started

Important

This library requires python 3.5 and Django 2.1. If you need to install it on older Python/Django versions, you may need to install an older release.

Installing the library and configuring a Django project to use it can be achieved in a few minutes. Follow Quickstart for very basic setup process. Later, when you will need to configure more precisely your project, follow other topics in the menu.

Quickstart

Installation

Install django-modern-rpc in your environment, using pip or equivalent tool

pip install django-modern-rpc

Add modernrpc app to settings.INSTALLED_APPS:

myproject/settings.py

 INSTALLED_APPS = [
     # ...
     'modernrpc',
 ]

Declare a procedure

Remote procedures are global Python functions decorated with @rpc_method.

myapp/remote_procedures.py

 from modernrpc.core import rpc_method

 @rpc_method
 def add(a, b):
     return a + b

@rpc_method behavior can be customized to your needs. Read Procedures registration for a full list of available options.

Locate procedures modules

Django-modern-rpc will automatically register functions decorated with @rpc_method, but needs a hint to locate them. Set settings.MODERNRPC_METHODS_MODULES variable to indicate project’s modules where remote procedures are declared.

myproject/settings.py

 MODERNRPC_METHODS_MODULES = [
     'myapp.remote_procedures'
 ]

Create an entry point

The entrypoint is a special Django view handling RPC calls. Like any other view, it must be declared in URLConf or any app specific urls.py:

myproject/urls.py

 from django.urls import path
 from modernrpc.views import RPCEntryPoint

 urlpatterns = [
     # ... other url patterns
     path('rpc/', RPCEntryPoint.as_view()),
 ]

Entry points behavior can be customized to your needs. Read Entrypoints configuration for full documentation.

Test the server

Start your project using python manage.py runserver and call your procedure using JSON-RPC or XML-RPC client, or directly with your favourite HTTP client

JSON-RPC example

 ~  $ curl -X POST localhost:8000/rpc -H "Content-Type: application/json" -d '{"id": 1, "method": "system.listMethods", "jsonrpc": "2.0"}'
 {"id": 1, "jsonrpc": "2.0", "result": ["add", "system.listMethods", "system.methodHelp", "system.methodSignature"]}

 ~  $ curl -X POST localhost:8000/rpc -H "Content-Type: application/json" -d '{"id": 2, "method": "add", "params": [5, 9], "jsonrpc": "2.0"}'
 {"id": 2, "jsonrpc": "2.0", "result": 14}

XML-RPC example

from xmlrpc.client import ServerProxy

with ServerProxy("http://localhost:8000/rpc") as proxy:
    proxy.system.listMethods()
    proxy.add(5, 9)

 # ['add', 'system.listMethods', 'system.methodHelp', 'system.methodSignature', 'system.multicall']
 # 14

Procedures registration

Introduction

Any global python function can be exposed. Simply decorate it with modernrpc.core.rpc_method:

myproject/myapp/remote_procedures.py

from modernrpc.core import rpc_method

@rpc_method
def add(a, b):
    return a + b

Django-modern-rpc will automatically register procedures at startup, as long as the containing module is listed in settings.MODERNRPC_METHODS_MODULES:

settings.py

MODERNRPC_METHODS_MODULES = [
    "myapp.remote_procedures",
]

Note

Automatic registration is performed in modernrpc.apps.ModernRpcConfig.ready(). See Django docs for additional information.

Customize registration

Without any argument, @rpc_method decorator will register the procedure with default parameters. It will be available for all entry points, any protocol (XML-RPC or JSON-RPC) and will have the function name as procedure’s “methodName”.

You can also change this behavior by adding arguments:

Procedure name

Use name to override the exposed procedure’s “methodName”. This is useful to setup a dotted name, which is not allowed in python.

Default: name = None

@rpc_method(name='math.add')
def add(a, b):
    return a + b

Protocol availability

When a procedure must be exposed only to a specific protocol, set protocol argument to Protocol.JSON_RPC or Protocol.XML_RPC.

Default: protocol = Protocol.ALL

from modernrpc.core import rpc_method, Protocol

@rpc_method(protocol=Protocol.JSON_RPC)
def add(a, b):
    return a + b

Note

Don’t forget to import modernrpc.core.Protocol enum.

Entry point

If you declared multiple entry points (see Declare multiple entry points) and want a procedure to be exposed only from one of them, provide its name using entry_point argument. You can also expose a procedure to 2 or more entry points by setting a list of strings.

Default: entry_point = modernrpc.core.ALL

# This will expose the procedure to "apiV2" entry point only"
@rpc_method(entry_point="apiV2")
def add(a, b):
    return a + b

# This will expose the procedure to 2 different entry points
@rpc_method(entry_point=["apiV2", "legacy"])
def multiply(a, b):
    return a * b

Access internal information

If you need to access some environment from your RPC method, simply adds **kwargs in function parameters. When the function will be executed, a dict will be passed as argument, providing the following information:

Current HTTP request (HttpRequest instance)

Current protocol (JSON-RPC or XML-RPC)

Current entry point name

Current handler instance

See the example to see how to access these values:

from modernrpc.core import rpc_method, REQUEST_KEY, ENTRY_POINT_KEY, PROTOCOL_KEY, HANDLER_KEY

@rpc_method
def content_type_printer(**kwargs):

    # Get the current request
    request = kwargs.get(REQUEST_KEY)

    # Other available objects are:
    # protocol = kwargs.get(PROTOCOL_KEY)
    # entry_point = kwargs.get(ENTRY_POINT_KEY)
    # handler = kwargs.get(HANDLER_KEY)

    # Return the Content-Type of the current request
    return request.content_type

Entrypoints configuration

Django-modern-rpc provides a class-based view modernrpc.views.RPCEntryPoint to handle remote procedure calls.

Usage

RPCEntryPoint is a standard Django view, you can declare it in your project or app’s urls.py:

urls.py

 from django.urls import path
 from modernrpc.views import RPCEntryPoint

 urlpatterns = [
     # ... other views
     path('rpc/', RPCEntryPoint.as_view()),
 ]

Then, all requests to http://yourwebsite/rpc/ will be routed to the view. They will be inspected and parsed to be interpreted as RPC call. The result of procedure call will be encapsulated into a response according to the request’s protocol (JSON-RPC or XML-RPC).

Advanced configuration

You can modify the behavior of the entry point by passing arguments to as_view().

Restrict supported protocol

Using protocol parameter, you can make sure a given entry point will handle only JSON-RPC or XML-RPC requests. This can be used to setup protocol-specific paths.

Default: protocol = Protocol.ALL

urls.py

 from django.urls import path

 from modernrpc.core import Protocol
 from modernrpc.views import RPCEntryPoint

 urlpatterns = [
     path('json-rpc/', RPCEntryPoint.as_view(protocol=Protocol.JSON_RPC)),
     path('xml-rpc/', RPCEntryPoint.as_view(protocol=Protocol.XML_RPC)),
 ]

Declare multiple entry points

Using entry_point parameter, you can declare different entry points. Later, you will be able to configure your RPC methods to be available to one or more specific entry points (see Procedure registration - entry point)

Default: entry_point = ALL

urls.py

 from django.urls import path

 from modernrpc.views import RPCEntryPoint

 urlpatterns = [
    path('rpc/', RPCEntryPoint.as_view(entry_point='apiV1')),
    path('rpcV2/', RPCEntryPoint.as_view(entry_point='apiV2')),
 ]

HTML documentation

RPCEntryPoint view can be configured to display HTML documentation of your procedures when it receive a GET request. To enable the feature, simply set enable_doc = True in your view instance.

Default: enable_doc = False

urls.py

 from django.urls import path

 from modernrpc.views import RPCEntryPoint

 urlpatterns = [
     # ...
     path('rpc/', RPCEntryPoint.as_view(enable_doc=True)),
 ]

The view will return HTML documentation on GET requests and process remote procedure calls on POST requests.

If you want a documentation-only entry point, set enable_rpc = False on documentation entry point.

Default: enable_rpc = True

urls.py

 urlpatterns = [
     # By default, RPCEntryPoint does NOT provide documentation but handle RPC requests
     path('rpc/', RPCEntryPoint.as_view()),

     # And you can configure it to display doc without handling RPC requests.
     path('rpc-doc/', RPCEntryPoint.as_view(enable_doc=True, enable_rpc=False)),
 ]

The complete documentation is available here Procedures documentation

Reference

class modernrpc.views.RPCEntryPoint(**kwargs)[source]

This is the main entry point class. It inherits standard Django View class.

get_context_data(**kwargs)[source]: Update context data with list of RPC methods of the current entry point. Will be used to display methods documentation page

handler_classes: Return the list of handlers to use when receiving RPC requests.

post(request, *args, **kwargs)[source]

Handle an XML-RPC or JSON-RPC request.

Parameters

request – Incoming request
args – Unused
kwargs – Unused

Returns

A HttpResponse containing XML-RPC or JSON-RPC response with the result of procedure call

Error handling

Introduction

When remote procedures are executed, errors can be caused by almost anything: invalid request payload, arguments deserialization or result serialization error, exception in method execution, etc. All errors must be handled properly for 2 reasons :

An error response must be returned to RPC client (with an error code and a textual message)
Developers should be able to detect such errors (using logs, error reporting tool like Sentry, etc.)

For that reasons, django-modern-rpc handle all errors with Python builtin exception system. This allows for very flexible error handling and allows to define custom exceptions with fixed error code and message.

Builtin exceptions

Hopefully, error codes for both JSON-RPC and XML-RPC are pretty similar. The following errors are fully supported in django-modern-rpc.

Code	Message
-32700	parse error. not well formed
-32600	Invalid request
-32601	Method not found
-32602	Invalid params
-32603	Internal error

Additional errors from XML-RPC specs are less relevant in modern web application, and have not been implemented.

Custom exceptions

When any exception is raised from a remote procedure, the client will get a default Internal Error as response. If you want to return a custom error code and message instead, simply define a custom exception. Create an RPCException sub-classes and set a faultCode to RPC_CUSTOM_ERROR_BASE + N with N a unique number.

Here is an example:

class MyException1(RPCException):
    def __init__(self, message):
        super().__init__(RPC_CUSTOM_ERROR_BASE + 1, message)

class MyException2(RPCException):
    def __init__(self, message):
        super().__init__(RPC_CUSTOM_ERROR_BASE + 2, message)

Such exceptions raised from your remote procedure will be properly returned to client.

Log errors

New in version 1.0.

By default, when an exception is caught from modernrpc code, a stacktrace of the error will be printed in the default log output. This allows developer to detect such case and fix the issue if needed.

To disable this behavior, set MODERNRPC_LOG_EXCEPTIONS to False.

Settings

Django-modern-rpc behavior can be customized by defining some values in project’s settings.py.

Basic settings

MODERNRPC_METHODS_MODULES

Required: Yes
Default: [] (Empty list)

Define the list of python modules containing RPC methods. You must set this list with at least one module. At startup, the list is looked up to register all python functions decorated with @rpc_method.

MODERNRPC_LOG_EXCEPTIONS

Required: No
Default: True

Set to False if you want to disable logging on exception catching

MODERNRPC_DOC_FORMAT

Required: No
Default: "" (Empty string)

Configure the format of the docstring used to document your RPC methods.

Possible values are: "", rst or markdown.

Note

The corresponding package is not automatically installed. You have to ensure library markdown or docutils is installed in your environment if set to a non-empty value

MODERNRPC_HANDLERS

Required: No
Default: ['modernrpc.handlers.JSONRPCHandler', 'modernrpc.handlers.XMLRPCHandler']

List of handler classes used by default in any RPCEntryPoint instance. If you defined your custom handler for any protocol, you can replace the default class used

MODERNRPC_DEFAULT_ENTRYPOINT_NAME

Required: No
Default: "__default_entry_point__"

Default name used for anonymous RPCEntryPoint

Protocol specific

You can configure how JSON-RPC handler will serialize and unserialize data:

MODERNRPC_JSON_DECODER

Required: No
Default: "json.decoder.JSONDecoder"

Decoder class used to convert JSON data to python values.

MODERNRPC_JSON_ENCODER

Required: No
Default: "django.core.serializers.json.DjangoJSONEncoder"

Encoder class used to convert python values to JSON data. Internally, modernrpc uses the default Django JSON encoder, which improves the builtin python encoder by adding support for additional types (DateTime, UUID, etc.).

MODERNRPC_XMLRPC_USE_BUILTIN_TYPES

Required: No
Default: True

Control how builtin types are handled by XML-RPC serializer and deserializer. If set to True (default), dates will be converted to datetime.datetime by XML-RPC deserializer. If set to False, dates will be converted to XML-RPC DateTime instances (or equivalent for Python 2).

This setting will be passed directly to ServerProxy instantiation.

MODERNRPC_XMLRPC_ALLOW_NONE

Required: No
Default: True

Control how XML-RPC serializer will handle None values. If set to True (default), None values will be converted to <nil>. If set to False, the serializer will raise a TypeError when encountering a None value.

MODERNRPC_XMLRPC_DEFAULT_ENCODING

Required: No
Default: None

Configure the default encoding used by XML-RPC serializer.

MODERNRPC_XML_USE_BUILTIN_TYPES

Deprecated. Define MODERNRPC_XMLRPC_USE_BUILTIN_TYPES instead.

Implementation details

XML-RPC

The most recent XML-RPC specification page used as reference for django-modern-rpc development is http://xmlrpc.com/spec.md. It is part of xmlrpc.com, a website created by Dave Winer in 2019 to propose updated tools around XML-RPC standard.

The original website (xmlrpc.scripting.com) has also been archived with a new URL: 1998.xmlrpc.com

System introspection methods

System introspection methods (listMethods, methodHelp, methodSignature) were not part of the original standard but were proposed in an unofficial addendum. Here is a list of references pages:

Multicall

Multicall was first proposed by Eric Kidd on 2001-01. Since the original article is now gone from the internet, it has been archived at https://mirrors.talideon.com/articles/multicall.html

JSON-RPC

Since JSON-RPC specification is more recent, available documentation is easier to find. The main specification is available at https://www.jsonrpc.org/specification

The current official standard for JSON format is RFC 8259.

Types support

Most of the time, django-modern-rpc will serialize and unserialize

RPC Data type	XML-RPC	JSON-RPC	Python conversion
null	✓ (1)	✓	None
string	✓	✓	str
int	✓	✓	int
float	✓	✓	float
boolean	✓	✓	bool
array	✓	✓	list
struct	✓	✓	dict
date	✓	✗ (2)	See (2)
bas64	✓ (3)	N/A	See (3)

(1) null and NoneType

By default, both JSON-RPC and XML-RPC handlers can serialize None and deserialize null value. The XML handler will convert such values to <nil/> special argument, JSON one will convert to JSON null.

But some old XML-RPC clients may misunderstand the <nil/> value. If needed, you can disable its support by setting MODERNRPC_XMLRPC_ALLOW_NONE to False. The XML-RPC marshaller will raise an exception on None serialization or <nil/> deserialization.

(2) Date types

JSON transport has no specific support of dates, they are transmitted as string formatted with ISO 8601 standard. The behavior of default encoder and decoder classes is:

Input date (RPC method argument)
- Dates are transmitted as standard string. Decoder will NOT try to recognize dates to apply specific treatment
Output date (RPC method return type)
- datetime.datetime objects will be automatically converted to string (format ISO 8601), so JSON-RPC clients will be able to handle it as usual. This behavior is due to the use of DjangoJSONEncoder as default encoder.

If you need to customize behavior of JSON encoder and/or decoder, you can specify another classes in settings.py:

MODERNRPC_JSON_DECODER = 'json.decoder.JSONDecoder'
MODERNRPC_JSON_ENCODER = 'django.core.serializers.json.DjangoJSONEncoder'

XML-RPC transport defines a type to handle dates and date/times: dateTime.iso8601. Conversion is done as follow:

Input date (RPC method argument)
- If settings.MODERNRPC_XMLRPC_USE_BUILTIN_TYPES = True (default), the date will be converted to datetime.datetime
- If settings.MODERNRPC_XMLRPC_USE_BUILTIN_TYPES = False, the date will be converted to xmlrpc.client.DateTime (Python 3) or xmlrpclib.DateTime (Python 2)
Output date (RPC method return type)
- Any object of type datetime.datetime, xmlrpclib.DateTime or xmlrpc.client.DateTime will be converted to dateTime.iso8601 in XML response

To simplify dates handling in your procedures, you can use get_builtin_date() helper to convert any input into a buildin datetime.datetime.

modernrpc.helpers.get_builtin_date(date: Union[str, datetime.datetime, xmlrpc.client.DateTime], date_format: str = '%Y-%m-%dT%H:%M:%S', raise_exception: bool = False) → Optional[datetime.datetime][source]

Try to convert a date to a builtin instance of datetime.datetime. The input date can be a str, a datetime.datetime, a xmlrpc.client.Datetime or a xmlrpclib.Datetime instance. The returned object is a datetime.datetime.

Parameters

date – The date object to convert.
date_format – If the given date is a str, format is passed to strptime to parse it
raise_exception – If set to True, an exception will be raised if the input string cannot be parsed

Returns

A valid datetime.datetime instance

base64

base64 is not specifically supported, but you should be able to serialize and unserialize base64 encoded data as string.

Logging

Internally, django-modern-rpc use Python logging system. While messages are usually hidden by default Django logging configuration, you can easily show them if needed.

You only have to configure settings.LOGGING to handle log messages from modernrpc module. Here is a basic example of such a configuration:

settings.py

 LOGGING = {
     'version': 1,
     'disable_existing_loggers': False,
     'formatters': {
         # Your formatters configuration...
     },
     'handlers': {
         'console': {
             'level': 'DEBUG',
             'class': 'logging.StreamHandler',
         },
     },
     'loggers': {
         # your other loggers configuration
         'modernrpc': {
             'handlers': ['console'],
             'level': 'DEBUG',
             'propagate': True,
         },
     }
 }

All information about logging configuration can be found in official Django docs.

Note

Logging configuration is optional. If not configured, the errors will still be visible in logs unless you set MODERNRPC_LOG_EXCEPTIONS to False. See Logging errors

System methods

XML-RPC specification doesn’t provide default methods to achieve introspection tasks, but some people proposed a standard for such methods. The original document is now offline, but has been retrieved from Google cache and is now hosted here.

system.listMethods

Return a list of all methods available.

system.methodSignature

Return the signature of a specific method

system.methodHelp

Return the documentation for a specific method.

system.multicall

Like 3 others, this system method is not part of the standard. But its behavior has been well defined by Eric Kidd. It is now implemented most of the XML-RPC servers and supported by number of clients (including Python’s ServerProxy).

This method can be used to make many RPC calls at once, by sending an array of RPC payload. The result is a list of responses, with the result for each individual request, or a corresponding fault result.

It is available only to XML-RPC clients, since JSON-RPC protocol specify how to call multiple RPC methods at once using batch request.

Authentication

django-modern-rpc provides a mechanism to check authentication before executing a given RPC method. It implemented at request level and is always checked before executing procedure.

Changed in version 1.0.0: In previous releases, authentication failures caused the view to return a 403 status code on response to standard (single) request, while batch requests / multicall always returned a 200 status with an error message. For consistency with XML-RPC specs, an authentication failure now returns a 200 response with a proper error (`error: -32603, message: Authentication failed when calling "<method_name>"`).

HTTP Basic Auth

django-modern-rpc comes with a builtin support for HTTP Basic Authentication. It provides a set of decorators to directly extract user information from request and test this user against Django authentication system.

from modernrpc.auth.basic import (
    http_basic_auth_login_required,
    http_basic_auth_superuser_required,
    http_basic_auth_permissions_required,
    http_basic_auth_any_of_permissions_required,
    http_basic_auth_group_member_required,
    http_basic_auth_all_groups_member_required
)
from modernrpc.core import rpc_method


@rpc_method
@http_basic_auth_login_required
def logged_user_required(x):
    """Access allowed only to logged users"""
    return x

@rpc_method
@http_basic_auth_superuser_required
def logged_superuser_required(x):
    """Access allowed only to superusers"""
    return x

@rpc_method
@http_basic_auth_permissions_required(permissions='auth.delete_user')
def delete_user_perm_required(x):
    """Access allowed only to users with specified permission"""
    return x

@rpc_method
@http_basic_auth_any_of_permissions_required(permissions=['auth.add_user', 'auth.change_user'])
def any_permission_required(x):
    """Access allowed only to users with at least 1 of the specified permissions"""
    return x

@rpc_method
@http_basic_auth_permissions_required(permissions=['auth.add_user', 'auth.change_user'])
def all_permissions_required(x):
    """Access allowed only to users with all the specified permissions"""
    return x

@rpc_method
@http_basic_auth_group_member_required(groups='A')
def in_group_A_required(x):
    """Access allowed only to users contained in specified group"""
    return x

@rpc_method
@http_basic_auth_group_member_required(groups=['A', 'B'])
def in_group_A_or_B_required(x):
    """Access allowed only to users contained in at least 1 of the specified group"""
    return x

@rpc_method
@http_basic_auth_all_groups_member_required(groups=['A', 'B'])
def in_groups_A_and_B_required_alt(x):
    """Access allowed only to users contained in all the specified group"""
    return x

Custom authentication system

To provide authentication features, django-modern-rpc introduce concept of “predicate”. This example will show you how to build a custom authentication system to restrict RPC method execution to clients that present a User-Agent different from a known list of bots.

def forbid_bots_access(request):
    """Return True when request has a User-Agent different from provided list"""
    if "User-Agent" not in request.headers:
        # No User-Agent provided, the request must be rejected
        return False

    forbidden_bots = [
        'Googlebot',  # Google
        'Bingbot',  # Microsoft
        'Slurp',  # Yahoo
        'DuckDuckBot',  # DuckDuckGo
        'Baiduspider',  # Baidu
        'YandexBot',  # Yandex
        'facebot',  # Facebook
    ]

    req_user_agent = request.headers["User-Agent"].lower()
    for bot_user_agent in [ua.lower() for ua in forbidden_bots]:
        # If we detect the caller is one of the bots listed above...
        if bot_user_agent in req_user_agent:
            # ... forbid access
            return False

    # In all other cases, allow access
    return True

Note

A predicate always takes a request as argument and returns a boolean value

It is associated with RPC method using @set_authentication_predicate decorator.

from modernrpc.core import rpc_method
from modernrpc.auth import set_authentication_predicate
from myproject.myapp.auth import forbid_bots_access

@rpc_method
@set_authentication_predicate(forbid_bots_access)
def my_rpc_method(a, b):
    return a + b

Now, the RPC method becomes unavailable to callers if User-Agent is not provided or if it has an invalid value.

In addition, you can provide arguments to your predicate using params:

@rpc_method
@set_authentication_predicate(my_predicate_with_params, params=('param_1', 42))
def my_rpc_method(a, b):
    return a + b

It is possible to declare multiple predicates for a single method. In such case, all predicates must return True to allow access to the method.

@rpc_method
@set_authentication_predicate(forbid_bots_access)
@set_authentication_predicate(my_predicate_with_params, params=('param_1', 42))
def my_rpc_method(a, b):
    return a + b

Procedures documentation

Django-modern-rpc can optionally process the docstring attached to your RPC methods and display it in a web page. This article will explain how generated documentation can bu used and customized.

Enable documentation

RPCEntryPoint class can be configured to provide HTML documentation of your RPC methods. To enable the feature, simply set enable_doc = True in your view instance

urlpatterns = [

    # Configure the RPCEntryPoint directly by passing some arguments to as_view() method
    path('rpc/', RPCEntryPoint.as_view(enable_doc=True)),
]

If you prefer provide documentation on a different URL than the one used to handle RPC requests, you just need to specify two different URLConf.

urlpatterns = [

    # By default, RPCEntryPoint does NOT provide documentation but handle RPC requests
    path('rpc/', RPCEntryPoint.as_view()),

    # And you can configure it to display doc without handling RPC requests.
    path('rpc-doc/', RPCEntryPoint.as_view(enable_doc=True, enable_rpc=False)),
]

Customize rendering

You can customize the documentation page by setting your own template. RPCEntryPoint inherits django.views.generic.base.TemplateView, so you have to set view’s template_name attribute:

urlpatterns = [
    # RPCEntryPoint can be configured with arguments passed to as_view()
    path(
      'rpc/',
      RPCEntryPoint.as_view(
        enable_doc=True,
        template_name='my_app/my_custom_doc_template.html'
      )
    ),
]

In the template, you will get a list of modernrpc.core.RPCMethod instance (one per registered RPC method). Each instance of this class has some methods and properties to retrieve documentation.

By default, documentation will be rendered using HTML5 vanilla tags with default classes and ids.

Changed in version 1.0.0: In previous releases, the default template was based on Bootstrap 4 with collapse components and accordion widgets. To use this BS4 template, simply set `template_name='modernrpc/bootstrap4/doc_index.html'` when instantiating the view.

Write documentation

The documentation is generated directly from RPC methods docstring

@rpc_method(name="util.printContentType")
def content_type_printer(**kwargs):
    """
    Inspect request to extract the Content-Type header if present.
    This method demonstrates how a RPC method can access the request object.
    :param kwargs: Dict with current request, protocol and entry_point information.
    :return: The Content-Type string for incoming request
    """
    # The other available variables are:
    # protocol = kwargs.get(MODERNRPC_PROTOCOL_PARAM_NAME)
    # entry_point = kwargs.get(MODERNRPC_ENTRY_POINT_PARAM_NAME)

    # Get the current request
    request = kwargs.get(REQUEST_KEY)
    # Return the content-type of the current request
    return request.META.get('Content-Type', '')

If you want to use Markdown or reStructuredText syntax in your RPC method documentation, you have to install the corresponding package in you environment.

pip install Markdown

pip install docutils

Then, set settings.MODERNRPC_DOC_FORMAT to indicate which parser must be used to process your docstrings

# In settings.py
MODERNRPC_DOC_FORMAT = 'markdown'

# In settings.py
MODERNRPC_DOC_FORMAT = 'rst'

New in version 1.0.0: Typehints are now supported to generate arguments and return type in documentation

Changelog

v1.0.0

Release date: 2023-01-03

After months of work, the 1.0 milestone is a major refactoring of the library. Many parts of the project have been modernized to improve readability and robustness, and a few issues were fixed.

Improvements

Type hinting is now supported in RPC methods. Auto-generated documentation will use it when it is defined. Old-style “doctypes” are still supported.
Dependency to six have been completely removed

Breaking Changes

When an authentication error is raised, the returned status code is now 200 instead of 403 for consistency with batch and system.multicall requests (#35)
Django < 2.1 and Python < 3.5 support have been dropped.

Other API changes

A new modernrpc.core.Protocol enum has been introduced to enforce correct protocol value when needed. (#29, #30). This new class replaces modernrpc.core.JSONRPC_PROTOCOL and modernrpc.core.XMLRPC_PROTOCOL but aliases were created for backward compatibility.
RPCUnknownMethod exception has been renamed to RPCMethodNotFound. An alias has been created for backward compatibility

Fixes

Initialization process updated: exceptions are now raised on startup for invalid RPC modules. In addition, Django check system is used to notify common errors. This was requested multiple times (#2, #13, #34).
JSON-RPC notification behavior has been fixed to respect standard. Requests without id are handled as notifications but requests with null id are considered invalid and will return an error
Batch request behavior has been fixed when one or more results failed to be serialized
Builtin system.methodSignature behavior have been updated to respect standard. It now returns a list of list and unknown types are returned as “undef” (see http://xmlrpc-c.sourceforge.net/introspection.html)

Misc

Added support for Python 3.9, 3.10 and 3.11
Added support for Django 3.2, 4.0 and 4.1
Documentation tree was completely reworked for clarity and simplicity. A new theme (Book) is now used to improve readability. See https://django-modern-rpc.rtfd.io.
Poetry is now used to configure project dependencies and build distributions. The new pyproject.toml file replaces setup.py, setup.cfg, MANIFEST.in and requirements.txt to centralize all dependencies, external tools settings (pytest, flake8, etc.) and packaging configuration
Black is now used to automatically format code
Mypy is now used to verify type hints consistency
Tox configuration now includes pylama, mypy, pylint and black environments
All tests have been rewritten to have a strong separation between unit and functional tests. Test classes where created to group tests by similarities. Many fixtures have been added, with more parameterization, resulting in about 350 tests executed covering more than 95% of the code.

v0.12.1

Release date: 2020-06-11

Fixes

Fix ImportError with Django 3.1

v0.12.0

Release date: 2019-12-05

Misc

Django 2.1, 2.2 and 3.0 are now officially supported. Thanks to @atodorov for 3.0 compatibility
Added Python 3.7 and 3.8 support
Dropped Python 3.3 support

Improvements

To ensure compatibility with JSON-RPC 1.2, 2 more “Content-Type” values are supported by JSON-RPC Handler: “application/json-rpc” and “application/jsonrequest” (#24). Thanks to @dansan

v0.11.1

Release date: 2018-05-13

Improvements

Last release introduced some undocumented breaking API changes regarding RPC registry management. Old API has been restored for backward compatibility. The following global functions are now back in the API:

modernrpc.core.register_rpc_method()
modernrpc.core.get_all_method_names()
modernrpc.core.get_all_methods()
modernrpc.core.get_method()
modernrpc.core.reset_registry()

In addition, some improvements have been applied to unit tests, to make sure test environment is the same after each test function. In addition, some exclusion patterns have been added in .coveragerc file to increase coverage report accuracy.

v0.11.0

Release date: 2018-04-25

Improvements

Django 2.0 is now officially supported. Tox and Travis default config have been updated to integrate Django 2.0 in existing tests environments.
Method’s documentation is generated only if needed and uses Django’s @cached_property decorator
HTML documentation default template has been updated: Bootstrap 4.1.0 stable is now used, and the rendering has been improved.
Many units tests have been improved. Some tests with many calls to LiveServer have been split into shorter ones.

API Changes

Class RPCRequest has been removed and replaced by method execute_procedure(name, args, kwargs) in RPCHandler class. This method contains common logic used to retrieve an RPC method, execute authentication predicates to make sure it can be run, execute the concrete method and return the result.
HTML documentation content is not marked as “safe” anymore, using django.utils.safestring.mark_safe(). You have to use Django decorator safe in your template if you display this value.

Settings

The kwargs dict passed to RPC methods can have customized keys (#18). Set the following values:
- settings.MODERNRPC_KWARGS_REQUEST_KEY
- settings.MODERNRPC_KWARGS_ENTRY_POINT_KEY
- settings.MODERNRPC_KWARGS_PROTOCOL_KEY
- settings.MODERNRPC_KWARGS_HANDLER_KEY

to override dict keys and prevent conflicts with your own methods arguments.

v0.10.0

Release date: 2017-12-06

Improvements

Logging system / error management
- In case of error, current exception stacktrace is now passed to logger by default. This allows special handler like django.utils.log.AdminEmailHandler or raven.handlers.logging.SentryHandler to use it to report more useful information (#13)
- Error messages have been rewritten to be consistent across all modules and classes
- Decrease log verbosity: some INFO log messages now have DEBUG level (startup methods registration)
Documentation has been updated
- Added a page to explain how to configure RPC methods documentation generation, and add a note to explicitly state that markdown or docutils package must be installed if settings.MODERNRPC_DOC_FORMAT is set to non-empty value (#16)
- Added a page to list implemented system introspection methods
- Added a bibliography page, to list all references used to write the library
Default template for generated RPC methods documentation now uses Bootstrap 4.0.0-beta.2 (previously 4.0.0-alpha.5)

v0.9.0

Release date: 2017-10-03

This is a major release with many improvements, protocol support and bug fixes. This version introduces an API break, please read carefully.

Improvements

Class RPCException and its subclasses now accept an additional data argument (#10). This is used by JSON-RPC handler to report additional information to user in case of error. This data is ignored by XML-RPC handler.
JSON-RPC: Batch requests are now supported (#11)
JSON-RPC: Named parameters are now supported (#12)
JSON-RPC: Notification calls are now supported. Missing “id” in a payload is no longer considered as invalid, but is correctly handled. No HTTP response is returned in such case, according to the standard.
XML-RPC: exception raised when serializing data to XML are now caught as InternalError and a clear error message

API Changes

Both modernrpc.handlers.JSONRPC and modernrpc.handlers.XMLRPC constants were moved and renamed. They become respectively modernrpc.core.JSONRPC_PROTOCOL and modernrpc.core.XMLRPC_PROTOCOL
RPCHandler class updated, as well as subclasses XMLRPCHandler and JSONRPCHandler. RPCHandler.parse_request() is now RPCHandler.process_request(). The new method does not return a tuple (method_name, params) anymore. Instead, it executes the underlying RPC method using new class RPCRequest. If you customized your handlers, please make sure you updated your code (if needed).

Fixes

Code has been improved to prepare future compatibility with Django 2.0

v0.8.1

Release date: 2017-10-02

important

This version is a security fix. Upgrade is highly recommended

Security fix

Authentication backend is correctly checked when executing method using system.multicall()

v0.8.0

Release date: 2017-07-12

Fixes

Fixed invalid HTML tag rendered from RPC Method documentation. Single new lines are converted to space since they are mostly used to limit docstrings line width. See pull request #7, thanks to @adamdonahue
Signature of auth.set_authentication_predicate has been fixed. It can now be used as decorator (#8). See the documentation for details. Thanks to @aplicacionamedida

v0.7.1

Release date: 2017-06-24

Fixes

Removed useless settings variable introduced in last 0.7.0 release. Logging capabilities are now enabled by simply configuring a logger for modernrpc.* modules, using Django variable LOGGING. The documentation has been updated accordingly.

v0.7.0

Release date: 2017-06-24

Improvements

Default logging behavior has changed. The library will not output any log anymore, unless MODERNRPC_ENABLE_LOGGING is set to True. See docs for details

v0.6.0

Release date: 2017-05-13

Improvements

Django cache system was previously used to store the list of available methods in the current project. This was useless, and caused issues with some cache systems (#5). Use of cache system has been removed. The list of RPC methods is computed when the application is started and kept in memory until it is stopped.

v0.5.2

Release date: 2017-04-18

Improvements

HTTP Basic Authentication backend: User instance is now correctly stored in current request after successful authentication (#4)
Unit testing with Django 1.11 is now performed against release version (Beta and RC are not tested anymore)
Various Documentation improvements

v0.5.1

Release date: 2017-03-25

Improvements

When RPC methods are registered, if a module file contains errors, a python warning is produced. This ensures the message will be displayed even if the logging system is not configured in a project (#2)
Python 2 strings standardization. Allow to configure an automatic conversion of incoming strings, to ensure they have the same type in RPC method, no matter what protocol was used to call it. Previously, due to different behavior between JSON and XML deserializers, strings were received as str when method was called via XML-RPC and as unicode with JSON-RPC. This standardization process is disabled by default, and can be configured for the whole project or for specific RPC methods.
Tests are performed against Django 1.11rc1
modernrpc.core.register_method() function was deprecated since version 0.4.0 and has been removed.

v0.5.0

Release date: 2017-02-18

Improvements

Typo fixes
JSON-RPC 2.0 standard explicitly allows requests without ‘params’ member. This doesn’t produce error anymore.
Setting variable MODERNRPC_XML_USE_BUILTIN_TYPES is now deprecated in favor of MODERNRPC_XMLRPC_USE_BUILTIN_TYPES
Unit tests are now performed with python 3.6 and Django 1.11 alpha, in addition to supported environment already tested. This is a first step to full support for these environments.
HTTP “Basic Auth” support: it is now possible to define RPC methods available only to specific users. The control can be done on various user attributes: group, permission, superuser status, etc. Authentication backend can be extended to support any method based on incoming request.

v0.4.2

Release date: 2016-11-20

Improvements

Various performance improvements
Better use of logging system (python builtin) to report errors & exceptions from library and RPC methods
Rewritten docstring parser. Markdown and reStructured formatters are still supported to generate HTML documentation for RPC methods. They now have unit tests to validate their behavior.
@rpc_method decorator can be used with or without the parenthesis (and this feature is tested)
System methods have been documented

v0.4.1

Release date: 2016-11-17

Improvements

Method arguments documentation keep the same order as defined in docstring
API change: MODERNRPC_ENTRY_POINTS_MODULES setting have been renamed to MODERNRPC_METHODS_MODULES.
A simple warning is displayed when MODERNRPC_METHODS_MODULES is not set, instead of a radical ImproperlyConfigured exception.
Some traces have been added to allow debugging in the module easily. It uses the builtin logging framework.

v0.4.0

Release date: 2016-11-17

API Changes

New unified way to register methods. Documentation in progress
XMl-RPC handler will now correctly serialize and unserialize None values by default. This behavior can be configured using MODERNRPC_XMLRPC_ALLOW_NONE setting.

Fixes

When django use a persistent cache (Redis, memcached, etc.), ensure the registry is up-to-date with current sources at startup

v0.3.2

Release date: 2016-10-26

Fixes

Include missing templates in pypi distribution packages

v0.3.1

Release date: 2016-10-26

Improvements

HTML documentation automatically generated for an entry point
system.multicall is now supported, only in XML-RPC
Many tests added

v0.3.0

Release date: 2016-10-18

API Changes

Settings variables have been renamed to limit conflicts with other libraries. In the future, all settings will have the same prefix.
- JSONRPC_DEFAULT_DECODER becomes MODERNRPC_JSON_DECODER
- JSONRPC_DEFAULT_ENCODER becomes MODERNRPC_JSON_ENCODER
See https://github.com/alorence/django-modern-rpc/blob/master/modernrpc/conf/default_settings.py for more details
Many other settings added, to make the library more configurable. See https://django-modern-rpc.rtfd.io/en/latest/basic_usage/settings.html

Improvements

RPC methods can now declare the special **kwargs parameter. The dict will contain information about current context (request, entry point, protocol, etc.)
About 12 tests added to increase coverage
Many documentation improvements
system.methodHelp is now supported

v0.2.3

Release date: 2016-10-13

Fixes

Packages modernrpc.tests and testsite were excluded from Pypi distribution (both binary and source). This action was forgotten in the last release

v0.2.2

Release date: 2016-10-13

Fixes

Packages modernrpc.tests and testsite were excluded from Pypi distribution (both binary and source)

v0.2.1

Release date: 2016-10-12

Improvements

Project is now configured to report tests coverage. See https://coveralls.io/github/alorence/django-modern-rpc
Some documentation have been added, to cover more features of the library. See https://django-modern-rpc.rtfd.io/
Many unit tests added to increase coverage
RPCEntryPoint class can now be configured to handle only requests from a specific protocol

v0.2.0

Release date: 2016-10-05

Improvements

Added very basic documentation: https://django-modern-rpc.rtfd.io/
system.listMethods is now supported
system.methodSignature is now supported
Error reporting has been improved. Correct error codes and messages are returned on usual fail cause. See module modernrpc.exceptions for more information.
Many unit tests have been added to increase test coverage of the library

v0.1.0

Release date: 2016-10-02

This is the very first version of the library. Only a subset of planned features were implemented

Current features

Work with Python 2.7, 3.3, 3.4 (Django 1.8 only) and 3.5
Work with Django 1.8, 1.9 and 1.10
JSON-RPC and XML-RPC simple requests support
Multiple entry-points with defined list of methods and supported protocols

Not implemented yet

No authentication support
Unit tests doesn’t cover all the code
RPC system methods utility (listMethods, methodSignature, etc.) are not yet implemented
There is no way to provide documentation in HTML form
The library itself doesn’t have any documentation (apart from the README.md)

Get involved

You can contribute to the project in multiple ways. Developer or not, all contributions are welcome.

Report issues, suggest enhancements

If you find a bug, want to ask question about configuration or suggest an improvement to the project, feel free to use the issue tracker. You will need a GitHub account. Please be kind and respectful, this project is maintained on free time by a single developer.

Submit a pull request

If you improved something or fixed a bug by yourself in a fork, you can submit a pull request. We will be happy to review it before doing a merge. The next page, Setup environment will explain how to configure a development environment in order to work on project source code.

Setup environment

Since 1.0, django-modern-rpc uses poetry as main tool to manage project dependencies, environments and packaging. It must be installed globally on your system.

Install poetry

There is multiple way to install poetry. Refer to official documentation and choose your preferred method.

If you already use pipx, installation is very quick and clean.

$ pipx install poetry

Alternatively, you can use the official get-poetry.py install script.

$ curl -sSL https://install.python-poetry.org | python3 -

Install dependencies

Dependencies are configured in pyproject.toml file. In addition, poetry.lock file contains resolved dependency tree. To install basic development environment, simply run

$ poetry install

Note

This command will automatically create a new environment if needed. You do not need to create it manually.

This will install everything needed to develop and test the library. In addition, optional group may be specified to enable other toolset (See below)

Run tests

The project have a lot of unit and functional tests to avoid regressions across new releases. They are automatically run on CI/CD platform (currently GitHub Actions) on each push, pull request and before every release.

But you should run tests on you development machine before submitting a new pull request.

System interpreter

To run test with your current python interpreter, simply run pytest inside poetry environment.

poetry run pytest

Python / Django versions matrix

If you have multiple python versions on your system, or if you have pyenv installed, you can setup tox and perform tests against multiple python / django versions

$ poetry install --with tox
$ pyenv local system 3.8 3.6 3.5
$ poetry run tox

To speedup tests run, you can use -p option to parallelize environment specific tests

$ poetry run tox -p 4

Caution

Don’t run too much parallel threads or you may slow down or completely freeze your machine !

Build docs

If you need to update documentation, first install required dependencies

poetry install --with docs

Then, cd into docs directory and use Makefile pre-defined commands.

To build docs with required options:

from docs/ directory

poetry run make html

The built files are stored inside dist/docs folder.

To simplify the writing process, you can run autobuild which automatically watch changes on files, rebuild docs and enable LiveServer on compatible browsers

from docs/ directory

poetry run make serve

Code quality

The project uses linting and formatting tools to unify source code definition and remove most of the typo and typing issues. You can run any tool directly inside poetry environment, or run them directly using tox (to unify command lines options used).

poetry install --with black,pylint,mypy,pylama
poetry run tox -e black,pylint,mypy,pylama

Important

These tools are run on GitHub Actions and will break the build on errors. Don’t forget to run the before submitting a pull request.

Home

Navigation

Home

Getting started

Quickstart

Installation

Declare a procedure

Locate procedures modules

Create an entry point

Test the server

Procedures registration

Introduction

Customize registration

Procedure name

Protocol availability

Entry point

Access internal information

Entrypoints configuration

Usage

Advanced configuration

Restrict supported protocol

Declare multiple entry points

HTML documentation

Reference

Error handling

Introduction

Builtin exceptions

Custom exceptions

Log errors

Settings

Basic settings

MODERNRPC_METHODS_MODULES

MODERNRPC_LOG_EXCEPTIONS

MODERNRPC_DOC_FORMAT

MODERNRPC_HANDLERS

MODERNRPC_DEFAULT_ENTRYPOINT_NAME

Protocol specific

MODERNRPC_JSON_DECODER

MODERNRPC_JSON_ENCODER

MODERNRPC_XMLRPC_USE_BUILTIN_TYPES

MODERNRPC_XMLRPC_ALLOW_NONE

MODERNRPC_XMLRPC_DEFAULT_ENCODING

MODERNRPC_XML_USE_BUILTIN_TYPES

Implementation details

XML-RPC

System introspection methods

Multicall

Other useful links

JSON-RPC

Types support

Logging

System methods

system.listMethods

system.methodSignature

system.methodHelp

system.multicall

Authentication

HTTP Basic Auth

Custom authentication system

Procedures documentation

Enable documentation

Customize rendering

Write documentation

Changelog

v1.0.0

Improvements

Breaking Changes

Other API changes

Fixes

Misc

v0.12.1

Fixes

v0.12.0

Misc

Improvements

v0.11.1

Improvements

v0.11.0

Improvements

API Changes