Components.js: Semantic Dependency Injection

Tracking #: 2945-4159

Ruben Taelman
Joachim Van Herwegen
Miel Vander Sande
Ruben Verborgh

Responsible editor: 
Aidan Hogan

Submission type: 
Tool/System Report
A common practice within object-oriented software is using composition to realize complex object behavior in a reusable way. Such compositions can be managed by Dependency Injection (DI), a popular technique in which components only depend on minimal interfaces and have their concrete dependencies passed into them. Instead of requiring program code, this separation enables describing the desired instantiations in declarative configuration files, such that objects can be wired together automatically at runtime. Configurations for existing DI frameworks typically only have local semantics, which limits their usage in other contexts. Yet some cases require configurations outside of their local scope, such as for the reproducibility of experiments, static program analysis, and semantic workflows. As such, there is a need for globally interoperable, addressable, and discoverable configurations, which can be achieved by leveraging Linked Data. We created Components.js as an open-source semantic DI framework for TypeScript and JavaScript applications, providing global semantics via Linked Data-based configuration files. In this article, we report on the Components.js framework by explaining its architecture and configuration, and discuss its impact by mentioning where and how applications use it. We show that Components.js is a stable framework that has seen significant uptake during the last couple of years. We recommend it for software projects that require high flexibility, configuration without code changes, sharing configurations with others, or applying these configurations in other contexts such as experimentation or static program analysis. We anticipate that Components.js will continue driving concrete research and development projects that require high degrees of customization to facilitate experimentation and testing, including the Comunica query engine and the Community Solid Server for decentralized data publication.
Full PDF Version: 


Solicited Reviews:
Click to Expand/Collapse
Review #1
By Pierre-Antoine Champin submitted on 06/Dec/2021
Review Comment:

This is the second version of this paper. I am satisfied with how the authors addressed my previous comments.

Review #2
By Esko Ikkala submitted on 13/Dec/2021
Review Comment:

Authors have improved the paper and the main issues mentioned by reviewers have been addressed accordingly.

Review #3
By Daniel Garijo submitted on 30/Dec/2021
Review Comment:

The author(s) have answered all my questions and addressed them in the paper, and I recommend its acceptance. I appreciate the addition of real world examples to illustrate some of the sections, and I would like to encourage their addition as part of the documentation of the ontology (even if it's simple, it always helps)

Unlike reviewer 1, I think the paper would be more readable by having footnotes instead of inline URLs, but I will leave that to the authors/editor.

A final answer to one of the comments in the rebuttal: I acknowledge that the paper does not claim Components.js to be more flexible than other DIs. However, there is an emphasis on this framework being used to build "more flexible applications". I thought this was due to the usage of the framework vs other DI frameworks.