This package defines a handler for Handlebars templates that can be used in Origami programs.

This is intended to be useful to Handlebars users, and also as a reference implementation of writing a handler for a new file type in Origami.

Installation

1. Add the @weborigami/handlebars package as a dependency in your project's package.json.
2. At the root of your project, create a file called config.ori that includes:

{
  hbs_handler = package:@weborigami/handlebars
}

This tells Origami to use the indicated package whenever it needs to process a Handlebars file with a .hbs extension.

You can then apply Handlebars templates as functions in Origami site definitions and in the terminal via the ori command-line interface.

The following use demos in the demos folder.

Invoking templates in the shell

Suppose a Handlebars template greet.hbs contains:

Hello, {{name}}!

You can invoke this Handlebars template as a function in the shell:

$ ori "greet.hbs('Alice')"
Hello, Alice!

Since the input here is a simple string, you can also using Origami's slash syntax:

$ ori greet.hbs/Bob
Hello, Bob!

Applying templates to data in data files

You can reference other files and pass those as input to a Handlebars template. Before invoking the template, Origami loads the data from a file if the file is a known built-in file type or known custom file type.

The demos/list directory has a data file countries.yaml that contains:

- name: France
  flag: 🇫🇷
- name: Greece
  flag: 🇬🇷
- name: Italy
  flag: 🇮🇹
- name: Portugal
  flag: 🇵🇹
- name: Spain
  flag: 🇪🇸

and a Handlebars template countries.hbs that contains

<ul>
  {{#each this}}
    <li>{{flag}} {{name}}</li>
  {{/each}}
</ul>

You can apply the template as a function to the data with

$ ori "countries.hbs(countries.yaml)"

Or take advantage of Origami's support for implicit parentheses to avoid the quotes:

$ ori countries.hbs countries.yaml

In either case, the output is

<ul>
  <li>🇫🇷 France</li>
  <li>🇬🇷 Greece</li>
  <li>🇮🇹 Italy</li>
  <li>🇵🇹 Portugal</li>
  <li>🇪🇸 Spain</li>
</ul>

You could also pull the data directly from a web server:

$ ori countries.hbs https://raw.githubusercontent.com/WebOrigami/extensions/main/handlebars/demos/list/countries.yaml

Applying templates to the file system

Because Origami treats the file system as a tree of resources, you can also feed a folder tree to a Handlebars template.

The demos/files folder has a folder of HTML files called pages.

$ ls pages
Alice.html Bob.html   Carol.html
$ cat pages/Alice.html
<p>Hello, <strong>Alice</strong>.</p>

The folder also contains a links.hbs template:

<ul>
  {{#each this}}
    <li>
      <a href="{{@key}}">{{this}}</a>
    </li>
  {{/each}}
</ul>

This pages folder can be passed as input to this template to generate a list of links to the files:

$ ori links.hbs pages

Origami loads all the files in the pages folder into an in-memory object, then passes that to the Handlebars template to produce:

<ul>
  <li>
    <a href="Alice.html">Alice.html</a>
  </li>
  <li>
    <a href="Bob.html">Bob.html</a>
  </li>
  <li>
    <a href="Carol.html">Carol.html</a>
  </li>
</ul>

Partial templates

Handlebars templates can reference partials: other templates that can be called by name. This Handlebars feature lets you break complex templates down into smaller parts.

Before invoking a Handlebars template, Origami resolves any partial templates it references.

The demos/partials folder contains a simple greet.hbs template:

Hello, {{#> bold }}{{this}}{{/bold}}!

Origami will resolve the bold reference by looking in scope for bold.hbs. In this case, Origami finds bold.hbs in that same folder:

<b>{{this}}</b>

Invoking the top-level greet.hbs template will then invoke the partial bold.hbs template to produce the final result:

$ ori greet.hbs/Carol
Hello, <b>Carol</b>!

Using Handlebars templates in an Origami site

You can reference Handlebars templates in Origami site definitions.

The demos/aboutUs folder contains the complete source for a simple About Us site. This is a variation of the sample About Us site developed in the Web Origami tutorial; see the tutorial for an explanation of how the site works.

In the Handlebars variation here, the tutorial's Origami templates are rewritten as equivalent Handlebars templates: the index.hbs template defines a team home page, and the person.hbs template defines a page for an individual team member.

Those templates are invoked by the top-level site.ori Origami program that defines the structure of the site.

// This file defines the site structure, using Handlebars templates to generate
// the index page and team member pages.
{
  index.html = index.hbs(teamData.yaml)
  team = @map(teamData.yaml, {
    key: (person) => `${person/name}.html`
    value: person.hbs
  })
  assets
  images
  thumbnails = @map(images, @image/resize({ width: 200 }))
}

The formula for index.html indicates that the index.hbs template should be applied to the data about team members in teamData.yaml. The formula for the team area indicates that Origami should generate a page for each team member using the person.hbs template.

You can run this site from the demos/aboutUs folder:

$ ori @serve site.ori

Larger example

The Aventour Expeditions sample site uses Handlebars to create a site for an adventure trekking company.