Include named exports of the Viewer, NavigatedViewer & Modeler classes

[BrianJVarley]

Describe the Bug

In Angular applications & libs, some development teams ban internal path imports from npm libraries. (no-restricted-imports). But in dmn-js lib there is no named exports for viewers only default export, which results in a long import path as - import Viewer from 'dmn-js/lib/NavigatedViewer. This gist also outlines some of the cons of using only default exports.

I'm proposing not so much a fix but just additionally exporting the viewer and modeler classes as named exports for convenience:

Pull Request: #946

Steps to Reproduce

Steps to reproduce the behaviour:

1. Import NavigatedViewer using named import - import { NavigatedViewer } from 'dmn-js';
2. Import is undefined, only default import exists with internal path - import Viewer from 'dmn-js/lib/NavigatedViewer

Expected Behavior

The library provides a named export for each viewer and modeler class. This is generally the norm for library imports within the Angular framework.

Environment

Please complete the following information:

• N/A
• N/A
• Library version: 17.2.0

[barmac]

Hi,

Thanks for opening the issue. While I'm not necessarily convinced that disallowing nested paths in imports is a good choice, I see some value in using named exports from the root as you suggested. This could simplify the usage of the library.
Still, since we'd rather roll out such change across the core bpmn.io libraries (bpmn-js, dmn-js, form-js), we need to discuss it internally first. I will keep you posted.

[BrianJVarley]

@barmac yeah that makes sense, agree it would simplify the usage of the library for devs.