front.app_maker#

The AppMaker orchestrator that turns a configuration into a front app.

Consumes a short-language configuration plus a convention, compiles it into a nested FrontSpec (the long language) via a spec maker, builds the composite tree of front elements, and assembles the runnable app.

Classes

AppMaker(spec_maker_factory[, ...])

Orchestrator that turns objects plus a configuration into a runnable front app.

class front.app_maker.AppMaker(spec_maker_factory, element_tree_maker_factory=<class 'front.elements.tree_maker_base.ElementTreeMaker'>)[source]#

Bases: object

Orchestrator that turns objects plus a configuration into a runnable front app.

Main class of front, doing the following:

Consume the configuration (short language) to produce a specification object (long language) using the provided spec maker. The specification is a nested structure which contains 3 sub-specification objects: “obj”, “rendering” and “app”.
Transform the input objects using the “trans” function from the “obj” specification (uses front.util.dflt_trans by default).
Build a composite tree of Front elements based on the “rendering” specification.
Build an app from the composite tree and “app” specification.

A concrete front framework subclasses SpecMakerBase (to supply its default convention, including the concrete element classes) and hands that class to AppMaker. Below, a minimal in-memory framework whose “app” is a container that renders each function’s docstring:

>>> from collections.abc import Callable
>>> from front import SpecMakerBase, APP_KEY, OBJ_KEY, RENDERING_KEY, ELEMENT_KEY
>>> from front.elements import FrontContainerBase, FrontComponentBase
>>> from front.util import dflt_trans
>>>
>>> class App(FrontContainerBase):
...     def render(self):
...         return {child.name: child() for child in self.children}
>>> class Doc(FrontComponentBase):
...     def render(self):
...         return self.obj.__doc__
>>> class SpecMaker(SpecMakerBase):
...     @property
...     def _dflt_convention(self):
...         return {
...             APP_KEY: {'title': 'Untitled'},
...             OBJ_KEY: {'trans': dflt_trans},
...             RENDERING_KEY: {ELEMENT_KEY: App, Callable: {ELEMENT_KEY: Doc}},
...         }
>>> def foo(a, b):
...     "Adds a and b."
...     return a + b
>>> app_maker = AppMaker(spec_maker_factory=SpecMaker)
>>> app = app_maker.mk_app([foo], config={APP_KEY: {'title': 'My App'}})
>>> app.name
'My App'
>>> app()
{'foo': 'Adds a and b.'}

Anything the config doesn’t say comes from the convention:

>>> app_maker.mk_app([foo]).name
'Untitled'