Loaders

Using these helper classes, you can define your bundles or even your complete environment in some external data source, rather than constructing them in code.

class webassets.loaders.YAMLLoader(file_or_filename)

Will load an environment or a set of bundles from YAML files.

load_bundles(environment=None)

Load a list of Bundle instances defined in the YAML file.

Expects the following format:

bundle-name:
    filters: sass,cssutils
    output: cache/default.css
    contents:
        - css/jquery.ui.calendar.css
        - css/jquery.ui.slider.css
another-bundle:
    # ...

Bundles may reference each other:

js-all:
    contents:
        - jquery.js
        - jquery-ui    # This is a bundle reference
jquery-ui:
    contents: jqueryui/*.js

If an environment argument is given, it’s bundles may be referenced as well. Note that you may pass any compatibly dict-like object.

Finally, you may also use nesting:

js-all:
    contents:
        - jquery.js
        # This is a nested bundle
        - contents: "*.coffee"
          filters: coffeescript

load_environment()

Load an Environment instance defined in the YAML file.

Expects the following format:

directory: ../static
url: /media
debug: True
updater: timestamp
filters:
    - my_custom_package.my_filter
config:
    compass_bin: /opt/compass
    another_custom_config_value: foo

bundles:
    # ...

All values, including directory and url are optional. The syntax for defining bundles is the same as for load_bundles().

Sample usage:

from webassets.loaders import YAMLLoader
loader = YAMLLoader('asset.yml')
env = loader.load_environment()

env['some-bundle'].urls()

class webassets.loaders.PythonLoader(module_name)

Basically just a simple helper to import a Python file and retrieve the bundles defined there.

load_bundles()

Load Bundle objects defined in the Python module.

Collects all bundles in the global namespace.

load_environment()

Load an Environment defined in the Python module.

Expects as default a global name environment to be defined, or overridden by passing a string module:environment to the constructor.