README.md

Pipelines JS

Pipelines JS is a library developed for purpose of composing logical blocks and actions into algorythm. Developing this library, next goals were claimed:

• Create a self-descriptive single-action processor

export class CreateTitle { }
export class CreateDescriptionBlock { }
export class HighlightSearchTextInDescription { }

• Possibility to combine processors together so they make up a bigger logical algorythm

export class ComposeNewsBlock {
    GetProcessors() {
        return [
            CreateTitle,
            CreateDescriptionBlock,
            HighlightSearchTextInDescription
        ]
    }
}

• It should be possible to extend algorythm (i.e. in the sample above I would like to add crop possibility, capitilize logic and logging mechanism to check state of the news block after each processor)

About the library

Abstractions

The main abstractions of the library represent two interfaces, which are: IProcessor and IPipeline.

• IProcessor - is an interface representing a unit which can process some information. You can think of it like about actions in command pattern. It defines and responsible only for a single method: Execute(args: Object): Promise<void>, which means that whatever information is passed, it will be somehow processed.
• IPipeline - binds together logical processors and itself represents a complete action instruction, which defines how processors must be executed.

Helpful classes

When abstractions are defined, it would be great to see them in action. For this purpose were created several useful classes: PipelineRunner, PipelineContext, SafeProcessor.

• PipelineRunner - simply runs your pipeline, a set of processors or a single processor.
• PipelineContext - introduces possibility to keep context information about the flow of the pipeline, like: messages and whether pipeline was aborted.
• SafeProcessor - implementation of the IProcessor, which has a condition, that checks parameters before they will be passed to execution.

Installation and Usage

$ npm install solid-pipelines

To make it easier to use this mechanism a yeoman generator was created, which can help you easily create common files, used with this library (the generator was also built with this library).