PipeLayer Framework

v0.6.0

Pipeline
Switch
Filter
- Events
- FilterEventArgs
Context
Manifest
Utilities

pipelayer.Pipeline(Filter)

Constructor:

__init__(steps, name)
- steps: List[Union[Step, PipelineCallableT]]
  - Classes and Instances that derive from pipelayer.Filter and implement the run method
  - Classes that implement the pipelayer.Step protocol
  - Functions (instance/class/static/module) that have the following signature def func(data: Any, context: Any)
  - Anonymous functions (lambda) with two arguments that follow this pattern: my_func = lambda data, context: data
- name: Optional[str]
  If not specified, the class name will be used.

Properties:

steps: List[Union[Step, PipelineCallableT]]
The list of filters to be executed
manifest: Manifest
An instance of pipelayer.Manifest that is created when the run method is called.

Events:

See Filter Events

Methods:

run(data, context) -> Any
The pipeline runner that iterates through the steps and pipes filter output to the next step.
- data: Optional[Any]
- context: Optional[pipelayer.Context]

pipelayer.Switch(Filter)

An implementation of a Switch statement as a pipeline filter

Constructor

__init__(expression, cases, name)
- expression: Union[Step, PipelineCallableT]
- cases: Dict[Any, Union[Step, PipelineCallableT]]
- name: Optional[str]
  If not specified, the class name will be used.

Properties:

expression: Union[Step, PipelineCallableT]
cases: Dict[Any, Union[Step, PipelineCallableT]]
name: Optional[str]
manifest: Manifest

Events:

See Filter Events

Methods:

run(data, context) -> Any
The runner that evaluates the specified expression and executes the matching case.

pipelayer.Filter

The filter abstract class that raises events.

Constructor

__init__(name)
- name: Optional[str]
  If not specified, the derived class name will be used.

Properties:

name: strThe name used by the manifest.

Events:

Events are lists of callables assigned after instantiation and are raised if the pipelayer.filter.raise_events decorator is applied to the implementation of the run method.

start: List[PipelineCallableT]
Raised before the run method is invoked.
exit: List[PipelineCallableT]
Raised if action is set to Action.SKIP or Action.EXIT in either a start or stop event handler.
end: List[PipelineCallableT]
Raised after the run method is invoked.

pipelayer.FilterEventArgs

__init__(data, context, state)
- data: Any
- context: Context
- state: State

pipelayer.Context

A abstract base class for runtime app data.

pipelayer.Manifest

The Manifest keeps a record of Pipeline and Filter activity.

pipelayer.util

render_manifest(manifest, indent) -> str
Static function that renders formatted JSON data
- manifest: Manifest
- indent: Optional[int]
  Default value is 2.