MoonTemplate

A Handlebars-style template engine for MoonBit. It supports variable interpolation, raw output, conditionals, unless, loops, comments, and safe-by-default HTML escaping.

Package metadata

Field	Value
MoonBit package	jshsj124/moontemplate
Version	0.1.1
Repository	https://github.com/jshsj124/MoonTemplate
License	MIT

The package name above matches moon.mod; publishing and importing must use this exact namespace. Older namespaces are not substitutes.

Installation

moon add jshsj124/moontemplate

Add the package to your app’s moon.pkg:

import {
  "jshsj124/moontemplate"
}

Complete runnable example

Create cmd/main/moon.pkg:

import {
  "jshsj124/moontemplate"
}

pkgtype(kind: "executable")

Create cmd/main/main.mbt:

///|
fn main {
  let template = "<h1>{{ title }}</h1>\n" +
    "<ul>{{#each items}}<li>{{ this }}</li>{{/each}}</ul>"
  let ctx = [
    ("title", "MoonTemplate <demo>"),
    ("items", "lexer,parser,renderer"),
  ]
  let html = @moontemplate.render_template(template, ctx)
  println(html)
}

Run it:

moon run cmd/main

Expected output:

<h1>MoonTemplate &lt;demo&gt;</h1>
<ul><li>lexer</li><li>parser</li><li>renderer</li></ul>

API

Function	Description
render_template(template, ctx)	Parse and render a template string in one call.
compile(template) -> @types.Node	Compile a template to a reusable AST.
render(ast, ctx) -> String	Render a compiled AST with context.
render_enhanced(template, ctx, partials, helpers)	Render with partial/helper arrays.
escape_html(text)	Escape HTML-sensitive characters: &, <, >, ", ', and backtick.

Context is an Array[(String, String)] of variable name-value pairs.

Template features

• Variable interpolation: {{ name }}
• Raw/unescaped output: {{{ html }}}
• Conditionals: {{#if show}}visible{{/if}}
• If/else: {{#if flag}}yes{{else}}no{{/if}}
• Unless: {{#unless hide}}visible{{/unless}}
• Loops: {{#each items}}{{ this }}{{/each}}
• Comments: {{! inline }} and {{!-- block --}}
• Automatic HTML escaping for normal interpolation

Development checks

moon check --deny-warn
moon fmt --check
moon info
git diff --exit-code -- '**/pkg.generated.mbti'
moon test --deny-warn

MoonBit 2026-07 no longer accepts --deny-warn on moon fmt or moon info; the commands above are the current toolchain equivalents. CI feature-detects older toolchains and runs the strict form when available.

License

MIT