twill-engine

Twill

The Twill.js is an ultra small (2k gzip) JS templating engine. Uses a part of dom to compile a dynamic html.

That is similar to Vue templates.

Syntax

Input:

<div
  t-each="field, k in fields"
  t-class="'fielt-' + field.required"
>

  <label
    t-for="field.name"
    t-text="k + '. ' + field.label"
  ></label>

  <input
    type="text"
    t-name="field.name"
    t-id="field.name"
    t-placeholder="field.placeholder"
    t-disabled="field.disabled"
  />

</div>

<div t-if="false">
  if false
</div>
<div t-if-else="false">
  if else false
</div>
<div t-if-else="true">
  if else true
</div>
<div else>
  else
</div>

<p>
  HTML: <span t-html="myHtml"></span>
</p>
<p>
  Text: <span t-text="myHtml"></span>
</p>

<p t-attr="data-id, data">Custom data-id attribute</p>

Output:

<div class="fielt-true">

  <label for="first_name">1. First Name</label>

  <input type="text" placeholder="Your First Name" name="first_name" id="first_name">

</div><div class="fielt-false">

  <label for="email">2. E-mail</label>

  <input type="text" placeholder="Your E-mail" disabled="true" name="email" id="email">

</div>

<div>
  if else true
</div>

<p>
  HTML: <span><b>Hello</b></span>
</p>
<p>
  Text: <span>&lt;b&gt;Hello&lt;/b&gt;</span>
</p>

<p data-id="123">Custom data-id attribute</p>

Usage

With webpack

Add package:

npm install twill-engine

Example:

import Twill from 'twill-engine'
// const Twill = require('twill-engine').default

const twill = new Twill()

const template = `<div t-if="false">some text</div>`
const vars = {}

const html = twill.parseHtml(template, vars)
console.log('html:', html)

Without webpack

Include to html:

<script src="https://cdn.jsdelivr.net/gh/rostber/twill@latest/dist/index.js" type="text/javascript">//</script>

Example:

const twill = new window.Twill()

const template = `<div t-if="false">some text</div>`
const vars = {}

const html = twill.parseHtml(template, vars)
console.log('html:', html)

Options

• prefix // The prefix of attributes
• directives // Custom default extension directives
• onError // The error callback

const twill = new Twill({
  prefix: 't-',
  directives: {
    json: (el, attr, name, data) => {
      el.innerText = JSON.stringify(this.variable(attr, data))
    },
    ....
  },
  onError: (e) => {
    console.log(e)
  }
})

Directives

Basic:

• t-each="item, k in items"
• t-if="myVar > true" / t-else-if="false" / t-else
• t-text="myVar"
• t-html="myFunct()"
• t-class="myVar ? 'enabled' : 'disabled'"

Attributes:

• t-id="'some string'"
• t-for="'some string'"
• t-value="'some string'"
• t-placeholder="'some string'"
• t-disabled="true"
• t-checked="true"
• t-readonly="true"
• t-href="url"
• t-name="field"
• t-style="'width: ' + w + 'px;'"

Custom attributes:

• t-attr="data-value, jsonVariable"

Expressions

Js standard expressions available:

<div t-text="true"></div>
<div t-text="false"></div>
<div t-text="'some string'"></div>
<div t-text="myVar >= 123"></div>
<div t-text="myVar.field.key"></div>
<div t-text="myVar + ' hello'"></div>
<div t-text="myVar ? 'show' : 'hide'"></div>
<div t-text="myVar.trim()"></div>
...

<div t-if="true"></div>
<div t-if="false"></div>
....

Methods

parseHtml

import Twill from 'twill-engine'

const twill = new Twill()
const template = `
<ul>
  <li t-each="item, k in items" t-text="item"></li>
</ul>
`
const html = twill.parseHtml(template, {items: [1, 2, 3]})
console.log('html:', html)

Output:

<ul>
  <li>1</li><li>2</li><li>3</li>
</ul>

parseNode

import Twill from 'twill-engine'

const twill = new Twill()
twill.parseNode(document.getElementById('example'), {items: [1, 2, 3]})

Input:

<div id="example">
  <ul>
    <li t-each="item, k in items" t-text="item"></li>
  </ul>
</div>

Output:

<div id="example">
  <ul>
    <li>1</li><li>2</li><li>3</li>
  </ul>
</div>

Console

Webpack commands

npm start
npm run tests
npm build