Handlebars.js Deployment and Usage Guide

Prerequisites

Node.js (version 12.0.0 or higher)
npm (version 6.0.0 or higher)
Git for cloning the repository

Installation

Clone the Repository

git clone https://github.com/handlebars-lang/handlebars.js.git
cd handlebars.js

Install Dependencies

npm install

Build the Project

npm run build

This will compile the source files and generate distributable versions in the dist/ directory.

Configuration

Handlebars.js does not require specific environment variables or API keys for basic usage. However, for development and testing:

Environment Variables

NODE_ENV - Set to development for development mode or production for production mode
No specific API keys are required for core functionality

Configuration Files

Handlebars uses a standard npm project structure. The main configuration is in package.json and Gruntfile.js for build tasks.

Build & Run

Development

To run in development mode with hot reloading:

npm run dev

Production

To build for production:

npm run build

The compiled files will be available in the dist/ directory:

dist/handlebars.js - Full version
dist/handlebars.runtime.js - Runtime-only version

Testing

To run the test suite:

npm test

Using in Your Project

Install Handlebars via npm:

npm install handlebars

Then use it in your JavaScript:

const Handlebars = require('handlebars');
const template = Handlebars.compile('Hello, {{name}}!');
console.log(template({ name: 'World' }));

Deployment

Node.js Applications

For Node.js applications, simply include Handlebars as a dependency in your package.json and use it as shown in the usage example above.

Browser Applications

For browser applications, include the compiled version:

<script src="https://cdnjs.cloudflare.com/ajax/libs/handlebars.js/4.7.7/handlebars.min.js"></script>
<script>
  const template = Handlebars.compile('Hello, {{name}}!');
  document.body.innerHTML = template({ name: 'World' });
</script>

CDN Deployment

You can also use a CDN for quick deployment:

<script src="https://cdn.jsdelivr.net/npm/handlebars@latest/dist/handlebars.min.js"></script>

Precompilation

For production environments, precompile your templates to improve performance:

npx handlebars template.hbs -f template.js

Troubleshooting

Common Issues

1. Template Compilation Errors

Issue: Template was precompiled with an older version of Handlebars than the current runtime

Solution: Ensure your precompiler version matches your runtime version. Update either your precompiler or runtime to compatible versions.

2. Build Failures

Issue: Build fails with missing dependencies

Solution: Run npm install to ensure all dependencies are installed. Check that you have the correct Node.js version.

3. Runtime Errors

Issue: No environment passed to template

Solution: Ensure you're passing the Handlebars environment when compiling templates:

const template = Handlebars.template(templateSpec, Handlebars);

4. Performance Issues

Issue: Templates are slow in production

Solution: Precompile your templates using the Handlebars precompiler. This reduces runtime compilation overhead.

Getting Help

Version Compatibility

Always ensure your precompiler version matches your runtime version. The COMPILER_REVISION and REVISION_CHANGES constants in the source code track compatibility between versions.

How to Deploy & Use wycats/handlebars.js