Flask-AssetRev

Flask-AssetRev is a Flask extension which adds support for mapping pre-built, content hashed static assets from the source form to the hashed version at runtime.

For example if your app served a simple script and css file on every page view, such as:

<html>
  <head>
    <script type="text/javascript" src="{{ url_for('static', filename='app.js') }}></script>
    <link rel="stylesheet" type="text/css" href="{{ url_for('static', filename='app.css') }}</script>
  </head>
  <body></body>
</html>

Everything works perfectly in development and you deploy your app to production. Users start complaining about errors and you realise that their version of app.js is being cached somehow out of your control. You decide that content hashing is the way to solve it. You use something like gulp-rev to produce the revved assets and move them in to the static sub-folder at build time.

But now the template above doesn't work. Flask-AssetRev solves this problem.

Rewriting your template to:

<html>
  <head>
    <script type="text/javascript" src="{{ asset_url('app.js') }}></script>
    <link rel="stylesheet" type="text/css" href="{{ asset_url('app.css') }}</script>
  </head>
  <body></body>
</html>

Using the code:

# app.py

from flask import Flask, render_template
from flask.ext import assetrev

app = flask.Flask(__name__)

assetrev.AssetRev(app)

@app.route('/')
def index():
    return render_template('index.html')

Will work for every version of the assets that you deploy.

Configuration Options

Name	Description
`ASSETREV_MANIFEST_FILE`	The mapping of source to revved asset json file as generated by `gulp-rev` (or similar). It must be within the same directory tree as the main flask app.
`ASSETREV_BASE_URL`	The url to find the compiled assets. By default the same host will be used. This allows the assets to be in a completely different domain.
`ASSETREV_BASE_PATH`	The directory within which to find the compiled assets in the app's static_folder.
`ASSETREV_RELOAD`	Whether to reload the asset manifest per request. By default, this is the same as `app.config['DEBUG']`.

Developer Guide

Setting up:

# assumes that virtualenvwrapper is installed
$ mkvirtualenv assetrev
(assetrev) $ pip install -r requirements_dev.txt
(assetrev) $ pip install -e .

Running the tests:

(assetrev) $ nosetests

njoyce/flask-assetrev

Flask-AssetRev

Configuration Options

Developer Guide