# Wax On [![Build Status](https://travis-ci.org/keithws/wax-on.svg?branch=master)](https://travis-ci.org/keithws/wax-on) [![NPM Dependency Status](https://david-dm.org/keithws/wax-on.svg)](https://david-dm.org/keithws/wax-on) [![NPM Verion](https://img.shields.io/npm/v/wax-on.svg)](https://www.npmjs.com/package/wax-on) Wax On adds support to Handlebars for template inheritance with the `block` and `extends` helpers. Directly inspired by [template Inheritance in Pug][1] and works the same way in [Handlebars][2]. ## Install ```shell npm install --save wax-on ``` ## Usage ```node // app.js const Handlebars = require("handlebars"); const wax = require("wax-on"); // register Wax On helpers with Handlebars wax.on(Handlebars); wax.setLayoutPath("/path/to/layouts"); ``` ### Extends The `extends` helper allows a template to extend a layout or parent template. It can then override certain pre-defined blocks of content. Note: You can have multiple levels of inheritance, allowing you to create powerful hierarchies of templates. ### Block Handlebars blocks can provide default content if desired, however optional as shown below by `block scripts`, `block content`, and `block foot`. ```handlebars {{! layout.hbs }} My Site — {{title}} {{#block "scripts"}} {{/block}} {{#block "content"}}{{/block}} {{#block "foot"}} {{/block}} ``` Now to extend the layout, simply create a new file and use the `extends` helper as shown below, giving the path ([server only][4]). You may now define one or more blocks that will override the parent block content, note that here the `foot` block is _not_ redefined and will output “some footer content”. ```handlebars {{! page-a.hbs }} {{#extends "layout"}} {{#block "scripts"}} {{/block}} {{#block "content"}}

{{title}}

{{#each pets as |petName|}}

{{petName}}

{{/each}} {{/block}} {{/extends}} ``` It’s also possible to override a block to provide additional blocks, as shown in the following example where the `content` block now exposes a `sidebar` and `primary` block for overriding, or the child template could override the `content` block all together. ```handlebars {{! sub-layout.hbs }} {{#extends "layout"}} {{#block "content"}}
{{#block "sidebar"}}

nothing

{{/block}}
{{#block "primary"}}

nothing

{{/block}}
{{/block}} {{/extends}} ``` ```handlebars {{! page-b.hbs }} {{#extends "sub-layout"}} {{#block "content"}}
{{#block "sidebar"}}

nothing

{{/block}}
{{#block "primary"}}

nothing

{{/block}}
{{/block}} {{/extends}} ``` ### Block Append / Prepend The `block` helper also allows you to prepend or append blocks in addition to the default behavior of replacing blocks. Suppose for example you have default scripts in a `head` block that you wish to utilize on every page, you might do this: ```handlebars {{! layout.hbs }} {{#block "head"}} {{/block}} {{#block "content"}}{{/block}} ``` ```handlebars {{! page.hbs }} {{#extends "layout"}} {{#block "head" mode="append"}} {{/block}} {{/extends}} ``` The `append` and `prepend` helpers make this common use case even easier. ```handlebars {{! page.hbs }} {{#extends "layout"}} {{#append "head"}} {{/append}} {{/extends}} ``` ## Todo In chronological order (most recent first); not in order of priority. Please create an issue if you'd like any of these changes or to recommend other changes. * add support for running in the browser (client-side) * investigate possibility of using partial blocks in addition to the extends helper ## Change Log The Wax On change log can be found in the [CHANGELOG.md][5] file within the project. ## License Wax On is available under the [MIT License][3]. [1]: https://pugjs.org/language/inheritance.html [2]: http://handlebarsjs.com [3]: https://github.com/keithws/wax-on/blob/master/LICENSE [4]: https://github.com/keithws/wax-on#todo [5]: https://github.com/keithws/wax-on/blob/master/CHANGELOG.md