jlto

Nodejs-based tool for optimizing Jinja like templates

Usage no npm install needed!

<script type="module">
  import jlto from 'https://cdn.skypack.dev/jlto';
</script>

README

JLTO

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NPM

Jinja Like Templates Optimizer (JLTO) is a Nodejs-based tool for optimizing Jinja like templates.

Gulp tool for JLTO:

gulp-jlto

Supported template engines:

Available options:

  • expressionStart - symbols at the beginning of expressions
  • expressionEnd - symbols at the end of expressions
  • blockStart - symbols at the beginning of blocks
  • blockEnd - symbols at the end of blocks
  • commentStart - symbols at the beginning of comments
  • commentEnd - symbols at the beginning of comments
  • specialChars - special chars in blocks and expressions
  • cleanupBlocks - flag for optimize blocks
  • cleanupExpressions - flag for optimize expressions
  • removeComments - flag for removing comments
  • minifyHtml - flag for minifying html code with html-minifier
  • minifyHtmlOptions - options for html-minifier

See default values for above options here.

Usage

Simple example:

let jlto = require('jlto')
let template = `
{{ hello }}
{{   "<John   &   Paul> ?"     | escape   }}
{{ '2.7'   | round }}{%  if  product  %}Product exists.{%  endif  %}
`
let optimizedTemplate = jlto.optimizeString(template)
// optimizedTemplate:
// `
//{{hello}}
//{{"<John   &   Paul> ?"|escape}}
//{{'2.7'|round}}{%if product%}Product exists.{%endif%}
// `

Example of using minifyHtml option:

let jlto = require('jlto')
let template = `
<div {% if id %}id="{{ id | escape('html_attr') }}"{% endif %} class="section-container {{ classes | join(' ') | html_attribute }}">
  <div class="section-writables">
    {% for writable in writables  %}
      {{ writable | write | raw }}
    {% endfor %}
  </div>
</div>`
let optimizedTemplate = jlto.optimizeString(template, {minifyHtml: true})
// optimizedTemplate:
// `<div {%if id%} id="{{id|escape('html_attr')}}" {%endif%} class="section-container {{classes|join(' ')|html_attribute}}"><div class="section-writables"> {%for writable in writables%} {{writable|write|raw}} {%endfor%} </div></div>`

Example of "nunjucks" templates minification with the custom GruntJS task:

module.exports = (grunt) => {
  grunt.registerTask('min-nunjucks', 'Min nunjucks templates', () => {
    let jlto = require('jlto')
    let fs = require('fs')
    let glob = require('glob')
    let done = this.async()
    glob('./**/*.nunjucks.html', (error, files) => {
      files.forEach((filePath) => {
        let fileContent
        fileContent = fs.readFileSync(filePath).toString()
        try {
          fileContent = jlto.optimizeString(fileContent, {minifyHtml: true})
          fs.writeFileSync(filePath, fileContent)
        } catch (ignored) {}
      })
      return done()
    })
  })
}

Tests

Unit tests are written using Mocha and Chai. To run, invoke npm test.

License

JLTO is available under the MIT license, see the LICENSE file for more information.