Introduce remote-templates support

[derberg]

Reason:

To simplify development of the templates, and also usage of templates we want to make it possible to publish templates separately and then have an option to use them in a generator from a remote location.

Description:

• we should not only support calling a template from a local directory, but also from remote location. NPM? Git? URL? check out how similar tools like yeoman are doing it
• have some kind of autodiscovery/registry mechanism so user can easily list available templates. With NPM it could be solved with the support of tags in package.json and NPM API
• it should be clear which templates are officially supported by asyncapi maintainers and which ones are not
• update docs!

[j-d-carmichael]

Is anyone already working on this?

[fmvilas]

Not yet but it's top priority right now so we should start working on it probably next week.

[j-d-carmichael]

How will you solve the core and template dependency alignment issue?

We initially just pulled the tpls in via git but then when the core brought in new features or a new format the older tpls started to break so we went with a quick and dirty solution of tagging the tpl git branches then comparing again the core npm version: https://github.com/acrontum/openapi-nodegen/blob/master/src/lib/template/TemplateFetch.ts#L183

We were just speaking the other day internally about changing this as confused a few of our team mates and to instead use the built in versioning system from NPM opposed to git tagging. It is a tricky one to solve and be clear to the end user.

Scenario being:
async-generator v1.5.0 would today work with template repo XYZ.
tomorrow ag v2.0.0 is released which breaks the rpl repo XYZ

[fmvilas]

I'm happy that you ask. This was partially solved already: #219.

There's also this issue: #237.

Everything related to making the Generator stable (i.e., v1.0.0) is our top priority so all these features/fixes should be implemented soon.

[j-d-carmichael]

Nice! Looking forward to it 👍

[jonaslagoni]

Implemented in #261

[fmvilas]

Thanks, man! 👍