[SOLVED] How to write my own handlebars helper and use it in patternlab-node?

How to write my own handlebars helper and use it in patternlab-node?

I am using Pattern Lab Node v2.12.0 on Windows, with Node v8.11.1, using a Gulp Edition.

I am very confused how to actually write my own handlebars helper and use it in patternlab-node. I read there are patternlab plugins but is this the correct way to load a handlebars helper?

I hope someone can point me in the right direction. I also didn't find any information about plugins or whatsoever on the official documentation page.

Thanks in advance.

Solution

For anyone also interested in this, I can recommend reading the issue I opened here https://github.com/pattern-lab/patternlab-node/issues/958 or read the source code of a working plugin I finally managed to create and publish here https://www.npmjs.com/package/plugin-node-patternlab-inline-assets.

Some clues I found out while reading Pattern Lab Node's source code

Plugin-Folders must start with a prefix "plugin-node-" (eg. plugin-node-myplugin) so Pattern Lab can find your plugin in node_modules (and otherwise it will not be executed)
You can access Handlebars.js in your plugin's exported function via passed patternlab Object in patternlab.engines.handlebars.engine where you can execute registerHelper to register your Handlebars.js helper.

module.exports = (patternlab) => {
    if (!patternlab) {
        process.exit(1);
    }

    patternlab.engines.handlebars.engine.registerHelper('your-helper', (parameter) => {
        return 'your result of the helper';
    });
};

For further reading, see the poor documentation: https://github.com/pattern-lab/patternlab-node/wiki/Creating-Plugins