Flask-Registry is an extension for Flask that allow frameworks to dynamically assemble your Flask application from reusable packages consisting of blueprints, extensions, and configuration.

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User’s Guide¶

This part of the documentation will show you how to get started in using Flask-Registry with Flask.

Installation¶

Install Flask-Registry with pip

pip install flask-registry

The development version can be downloaded from its page at GitHub.

git clone https://github.com/inveniosoftware/flask-registry.git
cd flask-registry
python setup.py develop
source run-tests.sh

Requirements¶

Flask-Registry has the following dependencies:

Flask
six

Flask-Registry requires Python version 2.6, 2.7 or 3.3+

Quickstart¶

This guide assumes you have successfully installed Flask-Registry and a working understanding of Flask. If not, follow the installation steps and read about Flask at http://flask.pocoo.org/docs/.

A Minimal Example¶

A minimal Flask-Registry usage example looks like this. First create the application and initialize the extension:

>>> from flask import Flask
>>> from flask_registry import Registry
>>> from flask_registry import ListRegistry
>>> app = Flask('myapp')
>>> r = Registry(app=app)

Then, we can create a simple ListRegistry that just keeps a list of objects:

>>> r['my_namespace'] = ListRegistry()
>>> r['my_namespace'].register("something")
>>> r['my_namespace'].register("something else")
>>> for obj in r['my_namespace']:
...     print(obj)
something
something else

Application Discovery Example¶

Flask-Registry also has support for dynamically discovering Python modules, resources, entry points and the like. All this can be put together in your Flask application factory to create and easily extensible application.

Following is a small example how a Flask application can be assemble from reusable packages that each provides configuration, extensions and blueprints:

from flask import Flask
from flask_registry import Registry, PackageRegistry, ExtensionRegistry, \
    ConfigurationRegistry, BlueprintAutoDiscoveryRegistry


class Config(object):
    PACKAGES = ['tests']
    EXTENSIONS = ['tests.mockext']
    USER_CFG = True


def create_app(config):
    app = Flask('myapp')
    app.config.from_object(config)
    r = Registry(app=app)
    r['packages'] = PackageRegistry(app)
    r['extensions'] = ExtensionRegistry(app)
    r['config'] = ConfigurationRegistry(app)
    r['blueprints'] = BlueprintAutoDiscoveryRegistry(app=app)
    return app

if __name__ == '__main__':
    config = Config()
    app = create_app(config)
    app.run(debug=True)

Save this in a file named app.py next to the tests folder in the Flask-Registry distribution and run it using your Python interpreter.

$ python app.py
 * Running on http://127.0.0.1:5000/
$ curl http://localhost:5000
Hello from Flask-Registry

The blueprint is loaded from tests.views and only works if the extension tests.mockext and the configuration in tests.config has been loaded.

See Application Discovery for full explanation on what is happening in the example.

Flask extension.

Flask-Registry is initialized like this:

>>> from flask import Flask
>>> from flask_registry import Registry, ListRegistry
>>> app = Flask('myapp')
>>> r = Registry(app=app)

A simple usage example of ListRegistry looks like this:

>>> app.extensions['registry']['my.namespace'] = ListRegistry()
>>> len(app.extensions['registry'])
1
>>> app.extensions['registry']['my.namespace'].register("something")
>>> app.extensions['registry']['my.namespace'].register("something else")
>>> len(app.extensions['registry']['my.namespace'])
2
>>> for obj in app.extensions['registry']['my.namespace']:
...     print(obj)
something
something else

Module Discovery¶

The module discovery registries provide discovery functionality useful for searching a list of Python packages for a specific module name, and afterwards registering the module. This is used to e.g. load and register Flask blueprints by BlueprintAutoDiscoveryRegistry.

Assume e.g. we want to discover the helpers module from the tests package. First we initialize the registry:

>>> from flask import Flask
>>> from flask_registry import Registry, ModuleDiscoveryRegistry
>>> from flask_registry import ImportPathRegistry
>>> app = Flask('myapp')
>>> r = Registry(app=app)

We then create the list of packages to search through using an ImportPathRegistry:

>>> r['mypackages'] = ImportPathRegistry(initial=['tests'])

Then, initialize the ModuleDiscoveryRegistry and run the discovery:

>>> r['mydiscoveredmodules'] = ModuleDiscoveryRegistry(
...     'helpers', registry_namespace='mypackages')
>>> len(r['mydiscoveredmodules'])
0
>>> r['mydiscoveredmodules'].discover(app=app)
>>> len(r['mydiscoveredmodules'])
1

Lazy discovery¶

Using RegistryProxy you may lazily discover modules. Above example using lazy loading looks like this:

>>> from flask_registry import RegistryProxy
>>> app = Flask('myapp')
>>> r = Registry(app=app)
>>> pkg_proxy = RegistryProxy('mypackages', ImportPathRegistry,
...     initial=['tests'])
>>> mod_proxy = RegistryProxy('mydiscoveredmodules',
...     ModuleDiscoveryRegistry,
...     'helpers',
...     registry_namespace=pkg_proxy)
>>> 'mypackages' in r
False
>>> 'mydiscoveredmodules' in r
False
>>> with app.app_context():
...     mod_proxy.discover(app=app)
>>> 'mypackages' in r
True
>>> 'mydiscoveredmodules' in r
True

Application Discovery¶

The application discovery registries provide discovery functionality useful for dynamically constructing Flask applications based on configuration variables. This allows a developer to package config, blueprints and extensions into isolated and reusable packages which a framework can dynamically install into a Flask application.

Such a package (named tests) could look like:

tests.views – contains blueprints which should be registered on the application object.

tests.mockext – contains a setup_app() method which be used to install any Flask extensions on the application object.

tests.config – contains configuration variables specific for this module.

Following is a simplified example of a Flask application factory, that will load config, extensions and blueprints:

>>> from flask import Flask, Blueprint
>>> from flask_registry import Registry, PackageRegistry
>>> from flask_registry import ExtensionRegistry
>>> from flask_registry import ConfigurationRegistry
>>> from flask_registry import BlueprintAutoDiscoveryRegistry
>>> class Config(object):
...     PACKAGES = ['tests']
...     EXTENSIONS = ['tests.mockext']
...     USER_CFG = True
>>> def create_app(config):
...     app = Flask('myapp')
...     app.config.from_object(config)
...     r = Registry(app=app)
...     r['packages'] = PackageRegistry(app)
...     r['extensions'] = ExtensionRegistry(app)
...     r['config'] = ConfigurationRegistry(app)
...     r['blueprints'] = BlueprintAutoDiscoveryRegistry(app=app)
...     return app
>>> config = Config()
>>> app = create_app(config)

Packages¶

The config variable PACKAGES specifies the list of Python packages, which ConfigurationRegistry and BlueprintAutoDiscoveryRegistry will search for config.py and views.py modules inside.

>>> for pkg in app.extensions['registry']['packages']:
...     print(pkg)
tests

Extensions¶

The config variable EXTENSIONS specifies the list of Python packages, which the ExtensionRegistry will load and call setup_app(app) on, to dynamically initialize Flask extensions.

>>> for pkg in app.extensions['registry']['extensions']:
...     print(pkg)
tests.mockext

Configuration¶

The ConfigurationRegistry will merge any package defined config, with the application config without overwriting already set variables in the application config:

>>> config.USER_CFG
True
>>> import tests.config
>>> tests.config.USER_CFG
False
>>> app.config['USER_CFG']
True

Blueprints¶

The BlueprintAutoDiscoveryRegistry will search for blueprints defined inside a views module in each package defined in PACAKGES. It will also register the discovered blueprints on the Flask application. Each views module should define either a single blueprint in the variable blueprint and/or multiple blueprints in the variable blueprints:

>>> from tests import views
>>> isinstance(views.blueprint, Blueprint)
True
>>> len(views.blueprints)
2
>>> for k in sorted(app.blueprints.keys()):
...     print(k)
test
test1
test2

Package Resources¶

Package resource registries may be used to discover e.g. package resources as well as loading entry points.

Entry points¶

setuptools entry points are a simple way for packages to “advertise” Python objects, so that frameworks can search for these entry points. setup.py files for instance allows you to specify console_scripts entry points, which will install scripts into system path for you.

The EntryPointRegistry allows you to easily register these entry points into your Flask application:

>>> from flask import Flask
>>> from flask_registry import Registry, EntryPointRegistry
>>> app = Flask('myapp')
>>> r = Registry(app=app)
>>> r['scripts'] = EntryPointRegistry('console_scripts')
>>> 'easy_install' in r['scripts']
True

Entry points are specified in you setup.py, e.g.:

setup(
    # ...
    entry_points={
        'flask_registry.test_entry': [
            'testcase = flask_registry:RegistryBase',
        ]
    },
    # ...
)

>>> r['entrypoints'] = EntryPointRegistry(
...     'flask_registry.test_entry', load=True)
>>> 'testcase' in r['entrypoints']
True
>>> from flask_registry import RegistryBase
>>> r['entrypoints']['testcase'][0] == RegistryBase
True

See http://pythonhosted.org/setuptools/pkg_resources.html#entry-points for more information on entry points.

Resource files¶

The PkgResourcesDirDiscoveryRegistry will search a list of Python packages for a specific resource directory and register all files found in the directories.

Assume e.g. a package tests have a directory resources with one file in it called testresource.cfg. This file can be discovered in the following manner:

>>> import os
>>> app = Flask('myapp')
>>> r = Registry(app=app)
>>> from flask_registry import ImportPathRegistry
>>> from flask_registry import PkgResourcesDirDiscoveryRegistry
>>> r['packages'] = ImportPathRegistry(initial=['tests'])
>>> r['res'] = PkgResourcesDirDiscoveryRegistry('resources', app=app)
>>> os.path.basename(r['res'][0]) == 'testresource.cfg'
True

Extending Flask-Registry¶

You can easily create your own type of registries by subclassing one of the existing registries found in the modules under flask_registry.registries.

If you for instance want to create a list registry that only accepts integers, you could create it like this:

>>> from flask import Flask
>>> from flask_registry import Registry, RegistryError, ListRegistry
>>> class IntListRegistry(ListRegistry):
...     def register(self, item):
...         if not isinstance(item, int):
...             raise ValueError("Object must be of type int")
>>> app = Flask('myapp')
>>> r = Registry(app=app)
>>> r['myns'] = IntListRegistry()
>>> r['myns'].register(1)
>>> r['myns'].register("some string")
Traceback (most recent call last):
  File "/usr/lib/python2.7/doctest.py", line 1289, in __run
    compileflags, 1) in test.globs
  File "<doctest default[7]>", line 1, in <module>
    r['myns'].register("some string")
  File "<doctest default[2]>", line 4, in register
    raise ValueError("Object must be of type int")
ValueError: Object must be of type int

API Reference¶

If you are looking for information on a specific function, class or method, this part of the documentation is for you.

API Docs¶

Flask extension.

Flask-Registry is initialized like this:

>>> from flask import Flask
>>> from flask_registry import Registry, ListRegistry
>>> app = Flask('myapp')
>>> r = Registry(app=app)

A simple usage example of ListRegistry looks like this:

>>> app.extensions['registry']['my.namespace'] = ListRegistry()
>>> len(app.extensions['registry'])
1
>>> app.extensions['registry']['my.namespace'].register("something")
>>> app.extensions['registry']['my.namespace'].register("something else")
>>> len(app.extensions['registry']['my.namespace'])
2
>>> for obj in app.extensions['registry']['my.namespace']:
...     print(obj)
something
something else

class flask_registry.Registry(app=None)¶

Flask extension.

Initialization of the extension:

>>> from flask import Flask
>>> from flask_registry import Registry
>>> app = Flask('myapp')
>>> r = Registry(app)
>>> app.extensions['registry']
<Registry ()>

or alternatively using the factory pattern:

>>> app = Flask('myapp')
>>> r = Registry()
>>> r.init_app(app)
>>> r
<Registry ()>

init_app(app)¶

Initialize a Flask application.

Only one Registry per application is allowed.

Parameters:	app (flask.Flask) – Flask application
Raises:	RegistryError – if the registry is already initialized

class flask_registry.RegistryProxy(namespace, registry_class, *args, **kwargs)¶

Lazy proxy object to a registry in the current_app

Allows you to define a registry in your local module without needing to initialize it first. Once accessed the first time, the registry will be initialized in the current_app, thus you must be working in either the Flask application context or request context.

>>> from flask import Flask
>>> app = Flask('myapp')
>>> from flask_registry import Registry, RegistryProxy, RegistryBase
>>> r = Registry(app=app)
>>> proxy = RegistryProxy('myns', RegistryBase)
>>> 'myns' in app.extensions['registry']
False
>>> with app.app_context():
...     print(proxy.namespace)
...
myns
>>> 'myns' in app.extensions['registry']
True

Parameters:	namespace – Namespace for registry registry_class – The registry class - i.e. a sublcass of `RegistryBase`. args – Arguments passed to `registry_class` on initialization. kwargs – Keyword arguments passed to `registry_class` on initialization.

class flask_registry.RegistryBase¶

Abstract base class for all registries.

Each subclass must implement the register() method. Each subclass may implement the unregister() method.

Once a registry is registered in the Flask application, the namespace under which it is available is injected into it self.

Please see flask_registry.registries.core for simple examples of subclasses.

namespace¶: Namespace. Used only by the Flask extension to inject the namespace under which this instance is registered in the Flask application. Defaults to None if not registered in a Flask application.

register(*args, **kwargs)¶: Abstract method which MUST be overwritten by subclasses. A subclass does not need to take the same number of arguments as the abstract base class.

unregister(*args, **kwargs)¶: Abstract method which MAY be overwritten by subclasses. A subclass does not need to take the same number of arguments as the abstract base class.

class flask_registry.RegistryError¶

Exception class raised for user errors.

e.g. creating two registries in the same namespace)

Core Registries¶

The core registries are useful to use as subclasses for other more advanced registries. The provide the basic functionality for list and dict style registries, as well as simple import path and module style registries.

class flask_registry.registries.core.ListRegistry¶

Basic registry that just keeps a list of objects. Provides normal list-style access to the registry:

>>> from flask import Flask
>>> from flask_registry import Registry, ListRegistry
>>> app = Flask('myapp')
>>> r = Registry(app=app)
>>> r['myns'] = ListRegistry()
>>> r['myns'].register("something")
>>> len(r['myns'])
1
>>> r['myns'][0]
'something'
>>> "something" in r['myns']
True
>>> for obj in r['myns']:
...     print(obj)
something

register(item)¶

Register a new object

Parameters:	item – Object to register

unregister(item)¶

Unregister an existing object. Raises a ValueError in case object does not exists. If the same object was registered twice, only the first registered object will be unregister.

Parameters:	item – Object to unregister

class flask_registry.registries.core.DictRegistry¶

Basic registry that just keeps a key, value pairs. Provides normal dict-style access to the registry:

>>> from flask import Flask
>>> from flask_registry import Registry, DictRegistry
>>> app = Flask('myapp')
>>> r = Registry(app=app)
>>> r['myns'] = DictRegistry()
>>> r['myns'].register("mykey", "something")
>>> len(r['myns'])
1
>>> r['myns']["mykey"]
'something'
>>> "mykey" in r['myns']
True
>>> for k, v in r['myns'].items():
...     print("%s: %s" % (k,v))
mykey: something

register(key, value)¶

Register a new object under a given key.

Parameters:	key – Key to register object under item – Object to register

unregister(key)¶: Unregister an object under a given key. Raises KeyError in case the given key doesn’t exists.

class flask_registry.registries.core.SingletonRegistry¶

Basic registry that just keeps a single object.

>>> from flask import Flask
>>> from flask_registry import Registry, SingletonRegistry
>>> app = Flask('myapp')
>>> r = Registry(app=app)
>>> r['singleton'] = SingletonRegistry()
>>> r['singleton'].register("test string")
>>> r['singleton'].get()
'test string'
>>> r['singleton'].register("another string")
Traceback (most recent call last):
    ...
RegistryError: Object already registered.
>>> r['singleton'].unregister()
>>> r['singleton'].get() is None
True
>>> r['singleton'].unregister()
Traceback (most recent call last):
    ...
RegistryError: No object to unregister.

get()¶: Get the registered object

register(obj)¶

Register a new singleton object

Parameters:	obj – The object to register

unregister()¶: Unregister the singleton object

class flask_registry.registries.core.ImportPathRegistry(initial=None, exclude=None, load_modules=False)¶

Registry of Python import paths. Supports simple discovery of modules without loading them.

>>> from flask import Flask
>>> from flask_registry import Registry, ImportPathRegistry
>>> app = Flask('myapp')
>>> r = Registry(app=app)
>>> r['myns'] = ImportPathRegistry(initial=[
... 'flask_registry.registries.*',
... 'flask_registry'])
>>> for imp_path in r['myns']:
...     print(imp_path)
flask_registry.registries.appdiscovery
flask_registry.registries.core
flask_registry.registries.modulediscovery
flask_registry.registries.pkgresources
flask_registry

When using star imports it is sometimes useful to exclude certain imports:

>>> r['myns2'] = ImportPathRegistry(
... initial=['flask_registry.registries.*',     ],
... exclude=['flask_registry.registries.core']
... )
>>> for imp_path in r['myns2']:
...     print(imp_path)
flask_registry.registries.appdiscovery
flask_registry.registries.modulediscovery
flask_registry.registries.pkgresources

Parameters:	initial – List of initial import paths. exclude – A list of import paths to not register. Useful together with star imports (`''`). Defaults to `[]`. load_modules* – Load the modules instead of just registering the import path. Defaults to `False`.

register(import_path)¶

Register a new import path

Parameters:	import_path – A full Python import path (e.g. `somepackge.somemodule`) or Python star import path to find all modules inside a package (e.g. `somepackge.*`).

unregister(*args, **kwargs)¶: It is not possible to unregister import paths.

class flask_registry.registries.core.ModuleRegistry(with_setup=True)¶

Registry for Python modules with setup and teardown functionality.

Each module may provide a setup() and teardown() function which will be called when the module is registered. The name of the methods can be customized by subclassing and setting the class attributes setup_func_name and teardown_func_name.

Any extra arguments and keyword arguments to register and unregister is passed to the setup and teardown functions.

Example:

import mod

registry = ModuleRegistry(with_setup=True)
registry.register(mod, arg1, arg2, kw1=...)
# Will call mod.setup(arg1, arg2, kw1=...)

Parameters:	with_setup – Call setup/teardown function when registering/unregistering modules. Defaults to `True`.

register(module, *args, **kwargs)¶

Parameters:	module – Module to register. args – Argument passed to the module setup function. kwargs – Keyword argument passed to the module setup function.

setup_func_name = 'setup'¶: Name of setup function. Defaults to setup.

teardown_func_name = 'teardown'¶: Name of teardown function. Defaults to teardown.

unregister(module, *args, **kwargs)¶

Parameters:	module – Module to unregister. args – Argument passed to the module teardown function. kwargs – Keyword argument passed to the module teardown function.

Application Discovery¶

The application discovery registries provide discovery functionality useful for dynamically constructing Flask applications based on configuration variables. This allows a developer to package config, blueprints and extensions into isolated and reusable packages which a framework can dynamically install into a Flask application.

Such a package (named tests) could look like:

tests.views – contains blueprints which should be registered on the application object.

tests.mockext – contains a setup_app() method which be used to install any Flask extensions on the application object.

tests.config – contains configuration variables specific for this module.

Following is a simplified example of a Flask application factory, that will load config, extensions and blueprints:

>>> from flask import Flask, Blueprint
>>> from flask_registry import Registry, PackageRegistry
>>> from flask_registry import ExtensionRegistry
>>> from flask_registry import ConfigurationRegistry
>>> from flask_registry import BlueprintAutoDiscoveryRegistry
>>> class Config(object):
...     PACKAGES = ['tests']
...     EXTENSIONS = ['tests.mockext']
...     USER_CFG = True
>>> def create_app(config):
...     app = Flask('myapp')
...     app.config.from_object(config)
...     r = Registry(app=app)
...     r['packages'] = PackageRegistry(app)
...     r['extensions'] = ExtensionRegistry(app)
...     r['config'] = ConfigurationRegistry(app)
...     r['blueprints'] = BlueprintAutoDiscoveryRegistry(app=app)
...     return app
>>> config = Config()
>>> app = create_app(config)

Packages¶

The config variable PACKAGES specifies the list of Python packages, which ConfigurationRegistry and BlueprintAutoDiscoveryRegistry will search for config.py and views.py modules inside.

>>> for pkg in app.extensions['registry']['packages']:
...     print(pkg)
tests

Extensions¶

The config variable EXTENSIONS specifies the list of Python packages, which the ExtensionRegistry will load and call setup_app(app) on, to dynamically initialize Flask extensions.

>>> for pkg in app.extensions['registry']['extensions']:
...     print(pkg)
tests.mockext

Configuration¶

The ConfigurationRegistry will merge any package defined config, with the application config without overwriting already set variables in the application config:

>>> config.USER_CFG
True
>>> import tests.config
>>> tests.config.USER_CFG
False
>>> app.config['USER_CFG']
True

Blueprints¶

The BlueprintAutoDiscoveryRegistry will search for blueprints defined inside a views module in each package defined in PACAKGES. It will also register the discovered blueprints on the Flask application. Each views module should define either a single blueprint in the variable blueprint and/or multiple blueprints in the variable blueprints:

>>> from tests import views
>>> isinstance(views.blueprint, Blueprint)
True
>>> len(views.blueprints)
2
>>> for k in sorted(app.blueprints.keys()):
...     print(k)
test
test1
test2

class flask_registry.registries.appdiscovery.PackageRegistry(app)¶

Specialized ImportPathRegistry that takes the initial list of import paths from the PACKAGES configuration variable in the application.

Parameters:	app – The Flask application object from which includes a `PACAKGES` variable in it’s configuration.

class flask_registry.registries.appdiscovery.ExtensionRegistry(app)¶

Flask extensions registry (Specialized ListRegistry). Loads all extensions specified by EXTENSIONS configuration variable. The registry will look for a setup_app function in the extension and call it if it exists.

Example configuration:

EXTENSIONS = [
    'invenio.ext.debug_toolbar',
    'invenio.ext.menu:MenuAlchemy',
]

Parameters:	app – Flask application to get configuration from.

register(app, ext_name)¶

Register a Flask extensions and call setup_app() on it.

Parameters:	app – Flask application object ext_name – An import path (e.g. a package, module, object) which when loaded has an method `setup_app()`.

unregister()¶: It is not possible to unregister configuration.

class flask_registry.registries.appdiscovery.ConfigurationRegistry(app, registry_namespace=None)¶

Specialized ModuleDiscoveryRegistry that search for config modules in a list of Python packages and merge them into the Flask application config without overwriting already set variables.

Parameters:	app – A Flask application registry_namespace – The registry namespace of an `ImportPathRegistry` with a list Python packages to search for `config` modules in. Defaults to `packages`.

register(new_object)¶

Register a new config module.

Parameters:	new_object – The configuration module. `app.config.from_object()` will be called on it.

unregister(*args, **kwargs)¶: It is not possible to unregister configuration.

class flask_registry.registries.appdiscovery.BlueprintAutoDiscoveryRegistry(module_name=None, app=None, with_setup=False, silent=False)¶

Specialized ModuleAutoDiscoveryRegistry that search for views modules in a list of Python packages and register blueprints found inside them.

Blueprints are loaded by searching for a variable blueprints (list of Blueprint instances) or blueprint (a Blueprint instance). If found, the blueprint will be registered on the Flask application.

A blueprint URL prefix can be overwritten using the BLUEPRINTS_URL_PREFIXES variable in the application configuration:

BLUEPRINTS_URL_PREFIXES = {
    '<blueprint name>': '<new url prefix>',
    # ...
}

Module Discovery¶

The module discovery registries provide discovery functionality useful for searching a list of Python packages for a specific module name, and afterwards registering the module. This is used to e.g. load and register Flask blueprints by BlueprintAutoDiscoveryRegistry.

Assume e.g. we want to discover the helpers module from the tests package. First we initialize the registry:

>>> from flask import Flask
>>> from flask_registry import Registry, ModuleDiscoveryRegistry
>>> from flask_registry import ImportPathRegistry
>>> app = Flask('myapp')
>>> r = Registry(app=app)

We then create the list of packages to search through using an ImportPathRegistry:

>>> r['mypackages'] = ImportPathRegistry(initial=['tests'])

Then, initialize the ModuleDiscoveryRegistry and run the discovery:

>>> r['mydiscoveredmodules'] = ModuleDiscoveryRegistry(
...     'helpers', registry_namespace='mypackages')
>>> len(r['mydiscoveredmodules'])
0
>>> r['mydiscoveredmodules'].discover(app=app)
>>> len(r['mydiscoveredmodules'])
1

Lazy discovery¶

Using RegistryProxy you may lazily discover modules. Above example using lazy loading looks like this:

>>> from flask_registry import RegistryProxy
>>> app = Flask('myapp')
>>> r = Registry(app=app)
>>> pkg_proxy = RegistryProxy('mypackages', ImportPathRegistry,
...     initial=['tests'])
>>> mod_proxy = RegistryProxy('mydiscoveredmodules',
...     ModuleDiscoveryRegistry,
...     'helpers',
...     registry_namespace=pkg_proxy)
>>> 'mypackages' in r
False
>>> 'mydiscoveredmodules' in r
False
>>> with app.app_context():
...     mod_proxy.discover(app=app)
>>> 'mypackages' in r
True
>>> 'mydiscoveredmodules' in r
True

class flask_registry.registries.modulediscovery.ModuleDiscoveryRegistry(module_name, registry_namespace=None, with_setup=False, silent=False)¶

Specialized ModuleRegistry that will search a list of Python packages in an ImportPathRegistry or ModuleRegistry for a specific module name. By default the list of Python packages is read from the packages registry namespace.

Packages may be excluded during the discovery using a configuration variables constructed according to the following pattern:

<NAMESPACE>_<MODULE_NAME>_EXCLUDE

where <NAMESPACE> should be replaced by the registry_namepsace, and <MOUDLE_NAME> should be replaced with module_name. Example: PACKAGES_VIEWS_EXCLUDE. All namespaces are capitalized and have dots replaced with underscores.

Subclasses of ModuleDiscoveryRegistry may overwrite the internal _discover_module() method to provide specialized discovery (see e.g. BlueprintAutoDiscoveryRegistry).

Parameters:

module_name – Name of module to search for in packages.
registry_namespace – The registry namespace of an ImportPathRegistry or ModuleRegistry with a list Python packages to search for module_name modules in. Alternatively to a registry namespace an instance of a RegistryProxy or Registry may also be used. Defaults to packages.
with_setup – Call setup and teardown function on discovered modules. Defaults to False (see ModuleRegistry).
silent – if set to True import errors are ignored. Defaults to False.

discover(app=None)¶

Perform module discovery, by iterating over the list of Python packages in the order they are specified.

Parameters:	app – Flask application object from where the list of Python packages is loaded (from the `registry_namespace`). Defaults to `current_app` if not specified (thus requires you are working in the Flask application context).

class flask_registry.registries.modulediscovery.ModuleAutoDiscoveryRegistry(module_name, app=None, registry_namespace=None, with_setup=False, silent=False)¶

Specialized ModuleDiscoveryRegistry that will discover modules immediately on initialization.

Parameters:

module_name – Name of module to search for in packages.
app – Flask application object
registry_namespace – The registry namespace of an ImportPathRegistry or ModuleRegistry with a list Python packages to search for module_name modules in. Alternatively to a registry namespace an instance of a RegistryProxy or Registry may also be used. Defaults to packages.
with_setup – Call setup and teardown function on discovered modules. Defaults to False (see ModuleRegistry).
silent – if set to True import errors are ignored. Defaults to False.

Package Resources¶

Package resource registries may be used to discover e.g. package resources as well as loading entry points.

Entry points¶

setuptools entry points are a simple way for packages to “advertise” Python objects, so that frameworks can search for these entry points. setup.py files for instance allows you to specify console_scripts entry points, which will install scripts into system path for you.

The EntryPointRegistry allows you to easily register these entry points into your Flask application:

>>> from flask import Flask
>>> from flask_registry import Registry, EntryPointRegistry
>>> app = Flask('myapp')
>>> r = Registry(app=app)
>>> r['scripts'] = EntryPointRegistry('console_scripts')
>>> 'easy_install' in r['scripts']
True

Entry points are specified in you setup.py, e.g.:

setup(
    # ...
    entry_points={
        'flask_registry.test_entry': [
            'testcase = flask_registry:RegistryBase',
        ]
    },
    # ...
)

>>> r['entrypoints'] = EntryPointRegistry(
...     'flask_registry.test_entry', load=True)
>>> 'testcase' in r['entrypoints']
True
>>> from flask_registry import RegistryBase
>>> r['entrypoints']['testcase'][0] == RegistryBase
True

See http://pythonhosted.org/setuptools/pkg_resources.html#entry-points for more information on entry points.

Resource files¶

The PkgResourcesDirDiscoveryRegistry will search a list of Python packages for a specific resource directory and register all files found in the directories.

Assume e.g. a package tests have a directory resources with one file in it called testresource.cfg. This file can be discovered in the following manner:

>>> import os
>>> app = Flask('myapp')
>>> r = Registry(app=app)
>>> from flask_registry import ImportPathRegistry
>>> from flask_registry import PkgResourcesDirDiscoveryRegistry
>>> r['packages'] = ImportPathRegistry(initial=['tests'])
>>> r['res'] = PkgResourcesDirDiscoveryRegistry('resources', app=app)
>>> os.path.basename(r['res'][0]) == 'testresource.cfg'
True

class flask_registry.registries.pkgresources.EntryPointRegistry(entry_point_ns, load=True)¶

Entry point registry. Based on DictRegistry with keys being the entry point group, and the value being a list of objects referenced by the entry points.

Parameters:	entry_point_ns – Entry point namespace load – if False, entry point will not be loaded. Defaults to `True`.

register(entry_point)¶

Register a new entry point

Parameters:	entry_point – The entry point

class flask_registry.registries.pkgresources.PkgResourcesDirDiscoveryRegistry(module_name, app=None, registry_namespace=None, with_setup=False, silent=False)¶: Specialized ModuleAutoDiscoveryRegistry that will search a list of Python packages in an ImportPathRegistry or ModuleRegistry for a specific resource directory and register all files found in the directories. By default the list of Python packages is read from the packages registry namespace.

Additional Notes¶

Notes on how to contribute, legal information and changelog are here for the interested.

Contributing¶

See <http://invenio-software.org/wiki/Development/Contributing> for now.

Changelog¶

Here you can see the full list of changes between each Flask-Registry release.

Version 0.2.0 (released 2014-06-27)¶

ListRegistry now fuly behaves as a list.
DictRegistry now fuly behaves as a dict.
Fixes issue with app in ModuleAutoDiscoveryRegistry.
Excludes option for ImportPathRegistry.
Fixes handling of missing package resource directory.
Fixes issue in configuration loading.
Allows removal of registries.
Fixes ImportError and SyntaxError handling.
Documentation and code coverage improvements.
Differentiates between missing and broken modules.
New BlueprintAutoDiscoveryRegistry.
New SingletonRegistry.

Version 0.1¶

Initial public release

License¶

Flask-Registry is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

Flask-Registry is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with Flask-Registry; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.

In applying this licence, CERN does not waive the privileges and immunities granted to it by virtue of its status as an Intergovernmental Organization or submit itself to any jurisdiction.

The full license text can be found below (GNU General Public License).

Authors¶

Flask-Registry is developed for use in Invenio digital library software.

Contact us at info@invenio-software.org

Contributors¶

Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
Jiri Kuncar <jiri.kuncar@cern.ch>
Esteban J. G. Gabancho <esteban.jose.garcia.gabancho@cern.ch>
Tibor Simko <tibor.simko@cern.ch>
Yoan Blanc <yoan@dosimple.ch>

GNU General Public License¶

GNU GENERAL PUBLIC LICENSE

Version 2, June 1991

Copyright (C) 1989, 1991 Free Software Foundation, Inc.

59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.

Preamble

The licenses for most software are designed to take away your

freedom to share and change it. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change free software–to make sure the software is free for all its users. This General Public License applies to most of the Free Software Foundation’s software and to any other program whose authors commit to using it. (Some other Free Software Foundation software is covered by the GNU Library General Public License instead.) You can apply it to your programs, too.

When we speak of free software, we are referring to freedom, not

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GNU GENERAL PUBLIC LICENSE

TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

This License applies to any program or other work which contains

a notice placed by the copyright holder saying it may be distributed under the terms of this General Public License. The “Program”, below, refers to any such program or work, and a “work based on the Program” means either the Program or any derivative work under copyright law: that is to say, a work containing the Program or a portion of it, either verbatim or with modifications and/or translated into another language. (Hereinafter, translation is included without limitation in the term “modification”.) Each licensee is addressed as “you”.

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source code as you receive it, in any medium, provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice and disclaimer of warranty; keep intact all the notices that refer to this License and to the absence of any warranty; and give any other recipients of the Program a copy of this License along with the Program.

You may charge a fee for the physical act of transferring a copy, and you may at your option offer warranty protection in exchange for a fee.

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b) You must cause any work that you distribute or publish, that in whole or in part contains or is derived from the Program or any part thereof, to be licensed as a whole at no charge to all third parties under the terms of this License.

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These requirements apply to the modified work as a whole. If identifiable sections of that work are not derived from the Program, and can be reasonably considered independent and separate works in themselves, then this License, and its terms, do not apply to those sections when you distribute them as separate works. But when you distribute the same sections as part of a whole which is a work based on the Program, the distribution of the whole must be on the terms of this License, whose permissions for other licensees extend to the entire whole, and thus to each and every part regardless of who wrote it.

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In addition, mere aggregation of another work not based on the Program with the Program (or with a work based on the Program) on a volume of a storage or distribution medium does not bring the other work under the scope of this License.

You may copy and distribute the Program (or a work based on it,

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a) Accompany it with the complete corresponding machine-readable source code, which must be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or,

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How to Apply These Terms to Your New Programs

If you develop a new program, and you want it to be of the greatest

possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms.

To do so, attach the following notices to the program. It is safest

to attach them to the start of each source file to most effectively convey the exclusion of warranty; and each file should have at least the “copyright” line and a pointer to where the full notice is found.

<one line to give the program’s name and a brief idea of what it does.> Copyright (C) <year> <name of author>

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

Also add information on how to contact you by electronic and paper mail.

If the program is interactive, make it output a short notice like this when it starts in an interactive mode:

Gnomovision version 69, Copyright (C) year name of author Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w’. This is free software, and you are welcome to redistribute it under certain conditions; type `show c’ for details.

The hypothetical commands `show w’ and `show c’ should show the appropriate parts of the General Public License. Of course, the commands you use may be called something other than `show w’ and `show c’; they could even be mouse-clicks or menu items–whatever suits your program.

You should also get your employer (if you work as a programmer) or your school, if any, to sign a “copyright disclaimer” for the program, if necessary. Here is a sample; alter the names:

Yoyodyne, Inc., hereby disclaims all copyright interest in the program `Gnomovision’ (which makes passes at compilers) written by James Hacker.

<signature of Ty Coon>, 1 April 1989 Ty Coon, President of Vice

This General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Library General Public License instead of this License.