ninjadog: pug + jinja2 == ❤️

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ninjadog

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Pug template (formerly jade) support in Python

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 bugs and the maintenance is a bit lacking.

It made more sense to me to use the existing nodejs implementation, and find a way to have it play nicely with Python.

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 be more reliable as it’s leveraging the popular and well-maintained nodejs implementation.

Command Line Interface

ninjadog v0.4.1

Render pug templates to html.

Usage:
    ninjadog string [options] <string>
    ninjadog file [options] <file>
    ninjadog dir [options] <source> [<destination>]
    ninjadog - [options]
    ninjadog -h | --help
    ninjadog -V | --version


Options:
    -h --help                 show help and exit
    -V --version              show version and exit
    -f --file <file>          the filepath to the template
    -p --pretty               pretty print output
    -c --context <context>    json string to be passed as context
    -j --with-jinja           render jinja2 syntax as well as pug
    -v --verbose              verbose output
    -n --dry-run              verbose output and exit without executing
    <destination>             destination directory to render pug files to


Strings may be passed via pipe using `-` argument.

i.e.

echo 'h1 hello {{ name }}' | ninjadog - -j -c '{"name": "Sam"}'

outputs

<h1>hello Sam</h1>

Pyramid

You can avoid having to render each template anew with every HTTP request. In your Pyramid configuration, you can have ninjadog cache templates by setting the ninjadog.cache option to true like so

[app:main]
ninjadog.cache = true
Configurator(settings={'ninjadog.cache': True})
# ...

… however you like to configure your app.

While this will make each page load much faster after the first visit, IT ALSO MEANS YOU CANNOT HAVE ANY MUTABLE STATE IN YOUR TEMPLATE as the template itself will only be rendered once.

It may be best to prototype by using ninjadog as normal - mutable state, conditionals, mixins… whatever - but to set the aformentioned option to true and move any logic dealing with mutable state into javascript for production. The choice yours.

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