Installation

ninjadog requires Python 3, node-js, npm, and the pug-cli library

brew install npm
npm install -g pug-cli
pip install ninjadog

For use with Pyramid, just add it to the configuration

config.include('ninjadog')

Usage

ninjadog leverages the pug-cli library, written in nodejs, to render pug templates in Python.

It allows you to take something like this

html
    head
        title my pug template
    body
        #content
            h1 Hello #{name}
            .block
                input#bar.foo1.foo2
                input(type="text", placeholder="your name")
                if name == "Bob"
                    h2 Hello Bob
                ul
                    for book in books
                        li= book
                    else
                        li sorry, no books

and sprinkle some Python over it

from ninjadog import render

context = {
    'name': 'Bob',
    'books': ['coloring book', 'audio book', "O'Reilly book"],
    'type': 'text',
}

print(render(file=filepath, context=context, pretty=True))

to render this

<!DOCTYPE html>
<html>
  <head>
    <title>my pug template</title>
  </head>
  <body>
    <div id="content">
      <h1>Hello Bob</h1>
      <div class="block">
        <input class="foo1 foo2" id="bar">
        <input type="text" placeholder="your name">
        <h2>Hello Bob</h2>
        <ul>
          <li>coloring book</li>
          <li>audio book</li>
          <li>O'Reilly book</li>
        </ul>
      </div>
    </div>
  </body>
</html>

You can even combine jinja2 syntax for unparalleled template-rendering power.

from ninjadog import render


def stop_believing():
    return False


context = {
    'stop_believing': stop_believing,
    'happy': {
        'birthday': 'today',
    }
}

template_string = """
h1 hello, world
if happy.birthday == 'today'
    p it's time to celebrate!
    p {{ "Don't" if not stop_believing() }} stop believing
"""

print(render(template_string,
             context=context,
             pretty=True,
             with_jinja=True))

<h1>hello, world</h1>
<p>it's time to celebrate!</p>
<p>Don't stop believing</p>

Why?

Pug templates are a super elegant and expressive way to write html, IMO.

There exists a project, pyjade and a less-popular fork, pypugjs, that are pure-python implementations of the pug template engine, but they have some minor bugs and the maintenance is a bit lacking.

I figured it would be good to have an alternative method to render pug templates that used the native javascript rendering engine.

ninjadog does this by spawning the pug cli as a subprocess. This means that it can’t be as fast as a native template engine like pyjade, but it will likely be more reliable over time as it’s leveraging the popular and well-maintained nodejs implementation.

Gotchas

Currently, rendering a template with jinja2 syntax goes through the following process:

1. Render elements on the initial template through jinja2

2. Pass the output to the pug-cli, gathering extensions and inclusions in the process

3. Render the output through jinja2 again, since the original template may have extended or included other templates that countained jinja2 syntax themselves.

What this means is that if you want to escape jinja2 syntax, you need to do it twice.

For example, to have a literal {{ escaping inception }} rendered, you’ll need to have {{ "{{ '{{ escaping inception }}' }}" }} in your template.

对不起