Getting Started

Fumanchu Getting Started Guide

Handlebars + Helpers Together

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Handlebars + Handlebars-helpers (helpers are now maintained in this project) combined into a single package. In addition this project has drastically reduced the number of dependencies.

Easily use it as a drop in replacement when using handlebars directly. More than 160 Handlebars helpers in ~20 categories. Helpers can be used with Assemble, Generate, Verb, Ghost, gulp-handlebars, grunt-handlebars, consolidate, or any node.js/Handlebars project. Currently 189 helpers in 20 categories! 🎉

Table of Contents

Usage Nodejs

npm install @jaredwray/fumanchu --save

To use Handlebars with all the helpers:

import {fumanchu} from '@jaredwray/fumanchu';
const handlebars = fumanchu(); // this will return handlebars with all the helpers
const template = handlebars.compile('{{#if (eq foo "bar")}}

Foo is bar

{{/if}}'
); const html = template({foo: 'bar'}); console.log(html); //

Foo is bar

It's just that easy! No need to add Handlebars to your project, it's already included.

Usage in the Browser

Fumanchu ships a browser-safe build that excludes Node-only helpers (fs, path, logging, embed, css, js, escape, urlResolve, urlParse, stripProtocol). Import it directly via the /browser subpath:

import { fumanchu } from '@jaredwray/fumanchu/browser';
const handlebars = fumanchu();
const template = handlebars.compile('{{uppercase name}}');
console.log(template({ name: 'hello' })); // HELLO

The package also sets the browser export condition on the main entry, so webpack, Vite, esbuild, Rollup, and other browser-aware bundlers automatically pick up the browser build when you import '@jaredwray/fumanchu' from a browser target — no code change required. The public API (fumanchu, helpers, HelperRegistry) is identical to Node; only the set of registered helpers differs.

You can also load the browser build directly from a CDN such as jsDelivr — no bundler required:

<script type="module">
  import { fumanchu } from 'https://cdn.jsdelivr.net/npm/@jaredwray/fumanchu/dist/index.browser.mjs';
  const handlebars = fumanchu();
  document.body.textContent = handlebars.compile('{{uppercase name}}')({ name: 'hello' });
script>

Using Handlebars Helpers

If you only want to use handlebar helpers you can easily do that by doing the following:

import {helpers} from '@jaredwray/fumanchu';
import handlebars from 'handlebars';
const helpersFunction = await helpers();
helpersFunction({ handlebars: handlebars });
const template = handlebars.compile('{{#if (eq foo "bar")}}

Foo is bar

{{/if}}'
); const html = template({foo: 'bar'}); console.log(html); //

Foo is bar

If using it with es6 you can access handlebars and helpers:

import {handlebars, helpers} from '@jaredwray/fumanchu';
helpers({ handlebars: handlebars });
const template = handlebars.compile('{{#if (eq foo "bar")}}

Foo is bar

{{/if}}'
); const html = template({foo: 'bar'}); console.log(html);

Using the Helper Registry

The helper registry allows you to manage and use Handlebars helpers more easily. You can register new helpers, filter existing ones, and access them in your templates.

import { HelperRegistry, handlebars } from '@jaredwray/fumanchu';

const registry = new HelperRegistry();
registry.register('eq', (a, b) => a === b);
registry.register('if', (condition, template) => condition ? template() : '');
const hbs = handlebars;
registry.load(hbs); // Load all helpers into Handlebars

If you want to do filtering you can use the HelperFilter on load:

import { HelperRegistry, handlebars } from '@jaredwray/fumanchu';

const registry = new HelperRegistry();
registry.register('eq', (a, b) => a === b);
registry.register('if', (condition, template) => condition ? template() : '');
const hbs = handlebars;
registry.load(hbs, { names: ['if']}); // Load the helpers into Handlebars

In addition, we have made the helper functions have a compatibility such as HelperRegistryCompatibility.NODEJS or HelperRegistryCompatibility.BROWSER. This will allow you to filter out based on your environment!

Caching

When caching is enabled, Fumanchu wraps the Handlebars compile() method to cache compiled template functions using @cacheable/memory. If you compile the same template string multiple times, the cached version is returned instead of recompiling. The returned Handlebars instance is fully compatible -- caching is transparent to your existing code.

The caching option accepts three types:

  • boolean -- true enables caching with defaults, false disables it
  • CacheableMemory -- a pre-configured instance from @cacheable/memory
  • CacheableMemoryOptions -- an options object passed to CacheableMemory (supports ttl, lruSize, checkInterval, etc.)

Here is an quick benchmark showing the performance advantage:

name summary ops/sec time/op margin samples
compile+render cached (v4.6.0) 🥇 45K 39µs ±0.32% 25K
compile+render no-cache (v4.6.0) -83% 8K 166µs ±0.62% 10K

Enable caching with default settings

import { fumanchu } from '@jaredwray/fumanchu';
const handlebars = fumanchu({ caching: true });

const template = handlebars.compile('Hello {{name}}!');
template({ name: 'World' }); // compiles and caches

const template2 = handlebars.compile('Hello {{name}}!');
// returns the cached compiled function -- no recompilation

Pass caching options

import { fumanchu } from '@jaredwray/fumanchu';
const handlebars = fumanchu({
  caching: {
    ttl: '1h',         // Time-to-live in ms or human-readable string like '1h'
    lruSize: 500,      // LRU cache size limit (0 = unlimited)
    checkInterval: 0,  // Interval to check for expired items in ms (0 = disabled)
  },
});

Pass a pre-configured CacheableMemory instance

This is useful if you want to share a cache across multiple Fumanchu instances or manage the cache lifecycle yourself:

import { fumanchu, CacheableMemory } from '@jaredwray/fumanchu';
const cache = new CacheableMemory({ ttl: '1h', lruSize: 1000, useClone: false });

const hbs1 = fumanchu({ caching: cache });
const hbs2 = fumanchu({ caching: cache }); // shares the same cache as hbs1