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

[michaelworm]

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.

[michaelworm]

So I tried writing my own plugin and use it via npm link. Pattern Lab says it has been installed correctly but it doesn't seem to be executed when building. Thanks to poor documentation I am really lost. Has anyone been able to write a working plugin and could help me out?

Edit
I found out that the plugin directory requires the prefix plugin-node- because Pattern Lab explicitly searches in node_modules for it, see https://github.com/pattern-lab/patternlab-node/blob/v2.12.0/core/lib/plugin_manager.js#L85

I had a hard time finding this one, this should definitely be pointed out in the documentation!

[engelfrost]

I have not tried writing a plugin recently, but I'm thinking that this functionality might be interesting inside the handlebars engine. Something like this:

1. Add a new setting in patternlab-config.json, e.g. engines.handlebars.helpers with a list of helpers ["path/to/helper.js", "path/to/helper-dir/"].
2. When the handlebars engine loads it reads the config and adds any helpers.

The React engine seems to do something similar:

patternlab-node/packages/engine-react/lib/engine_react.js

Line 227 in f4b839d

usePatternLabConfig: function(config) {

[engelfrost]

Got something working, submitting PR soon

[michaelworm]

@engelfrost really nice! Thank you! In the meanwhile I published a Pattern Lab plugin to resolve my usecase. If anyone is interested, feel free to use https://www.npmjs.com/package/plugin-node-patternlab-inline-assets

[engelfrost]

@Miw0 Cool, you figured the plugin thing out! I might combine our two solutions to make a helper-loading plugin.

[david-moldenhauer]

@Miw0 @engelfrost
Adding a Handlebars helper is done via the plugin setting inside the patternlab-config.json:
"plugins": {
"plugin-node-handlebars-helpers": {
"enabled": true,
"more_options": "options1"
}
}
the key "plugin-node-handlebars-helpers" is the npm modules name you can check https://github.com/david-moldenhauer/plugin-node-handlebars-helpers for more details.

[engelfrost]

Thanks @david-moldenhauer. A common way to add helpers/extensions to both Handlebars and Nunjucks is making it's way into the engines themselves now. If you have knowledge to add to the PR linked above based on your plugin that would be great!

[michaelworm]

@Miw0 @engelfrost
Adding a Handlebars helper is done via the plugin setting inside the patternlab-config.json:
"plugins": {
"plugin-node-handlebars-helpers": {
"enabled": true,
"more_options": "options1"
}
}
the key "plugin-node-handlebars-helpers" is the npm modules name you can check https://github.com/david-moldenhauer/plugin-node-handlebars-helpers for more details.

I first thought you build a plugin which would allow me to add any handlebars helper I need but I see that your plugin ist just a collection of useful util helpers. Anyway thanks for posting, this would have helped me alot 2 weeks ago!

[stale]

It's hard to keep track of everything. This issue has been automatically marked as stale because it has not had recent activity, neither from the team nor the community. It will be closed if no further activity occurs. Please consider adding additional info, volunteering to contribute a fix for this issue, or making a further case that this is important to you, the team, and the project as a whole. Thanks!

[stale]

Issue closed after going stale. It can be re-opened if still relevant.

[engelfrost]

Still relevant, waiting for PR to be processed

[stale]

It's hard to keep track of everything. This issue has been automatically marked as stale because it has not had recent activity, neither from the team nor the community. It will be closed if no further activity occurs. Please consider adding additional info, volunteering to contribute a fix for this issue, or making a further case that this is important to you, the team, and the project as a whole. Thanks!

[engelfrost]

Still relevant

[engelfrost]

For anyone else who is impatient and needs this in PL v2 I've created this Handlebars Engine for myself. The project will not be maintained in the long run: https://github.com/engelfrost/patternengine-node-handlebars-extended

[stale]

It's hard to keep track of everything. This issue has been automatically marked as stale because it has not had recent activity, neither from the team nor the community. It will be closed if no further activity occurs. Please consider adding additional info, volunteering to contribute a fix for this issue, or making a further case that this is important to you, the team, and the project as a whole. Thanks!

[stale]

Issue closed after going stale. It can be re-opened if still relevant.

[engelfrost]

PR still waiting to be processed

[stale]

It's hard to keep track of everything. This issue has been automatically marked as stale because it has not had recent activity, neither from the team nor the community. It will be closed if no further activity occurs. Please consider adding additional info, volunteering to contribute a fix for this issue, or making a further case that this is important to you, the team, and the project as a whole. Thanks!