Promistache - Embeddable {{Mustache}} Templating Engine

• Templates: {{#section}} {{> partial}} {{lambda}} {{/section}}
• Compiler: Precompile a .js file for Node.js and Web browsers ready.
• Render: Pair of synchronous render and Promise-based asynchronous render.
• Embeddable: Tiny 1KB runtime. No dependency modules required when rendering.

Synopsis

Asynchronous mode:

const Promistache = require("promistache");

const template = "hello, {{name}}!";

const render = Promistache.compileAsync(template);

const context = {name: "Ryu"};

render(context).then(console.log); // => "Hello, Ryu!"

Synchronous mode:

const Promistache = require("promistache");

const template = "hello, {{name}}!";

const render = Promistache.compile(template);

const context = {name: "Ryu"};

console.log(render(context)); // => "Hello, Ryu!"

CLI Compiler

promistache --help

promistache --variable=exports --runtime=sync *.html --output=templates.js

HTML Template: names.html

<ul>
  {{#list}}
  <li>{{name}}</li>
  {{/list}}
</ul>

Node.js:

const templates = require("./templates");

const context = {list: [{name: "Ryu"}, {name: "Ken"}]};

console.log(templates.names(context));

Browser:

<script src="./templates.js"></script>
<script>
    const context = {list: [{name: "Ryu"}, {name: "Ken"}]};
    document.body.innerHTML = exports.sample1(context);
</script>

Result:

<ul>
  <li>Ryu</li>
  <li>Ken</li>
</ul>

Templating Syntax

The compiled render method accepts a pair of arguments: the main (current) context and the alt (fallback) context.

const Promistache = require("promistache");

const template = "{{foo}}-{{.foo}}-{{>foo}} {{bar}}-{{.bar}}-{{>bar}}";

const context = { foo: "[FOO]" };
const alt = { foo: "[foo]", bar: "[bar]" };

const render = Promistache.compile(template);

console.log(render(context, alt)); // => "[FOO]-[FOO]-[foo] [bar]--[bar]"

Interpolation:

Prefix	Behavior	Example	Main context	Alt context	HTML escape
-	Normal	{{foo.bar}}	Yes (primary)	Yes (fallback)	Escaped
&	Unescaped	{{&foo.bar}}	Yes (primary)	Yes (fallback)	Raw
.	Main only	{{.foo.bar}}	Yes	No	Escaped
>	Alt only	{{>foo.bar}}	No	Yes	Raw

Section:

{{# section }} show this when true {{/ section }}

{{^ inverted }} show this when false {{/ inverted }}

Comment: (just ignored)

{{! comment }}

Triple Mustache: (rendered without HTML escaping)

{{{ foo.bar }}}

{{& foo.bar }} // same

Patial: (as a lambda stored in the alt context)

{{> partial }}

Altering Delimiter: (tag switching)

{{= <% %> =}}

<%# section %> <% foo.bar %> <%/ section %>

Incompatibility

It passes more than 90% of the original Mustache spec test suite. The rest of the tests are skipped in due to changes made for security or performance reasons. The following minor features are not supported by the module.

• A lambda's return value should be parsed.
• All elements on the context stack should be accessible.
• Each line of the partial should be indented before rendering.
• Lambdas used for inverted sections should be considered truthy.
• Lambdas used for sections should receive the raw section string.

GitHub

• https://github.com/kawanet/promistache

The MIT License (MIT)

Copyright (c) 2018-2021 Yusuke Kawasaki

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.