Book Image

Web Development with Django Cookbook- Second Edition - Second Edition

By : Aidas Bendoraitis
Book Image

Web Development with Django Cookbook- Second Edition - Second Edition

By: Aidas Bendoraitis

Overview of this book

Django is a web framework that was designed to strike a balance between rapid web development and high performance. It has the capacity to handle applications with high levels of user traffic and interaction, and can integrate with massive databases on the backend, constantly collecting and processing data in real time. Through this book, you'll discover that collecting data from different sources and providing it to others in different formats isn't as difficult as you thought. It follows a task-based approach to guide you through all the web development processes using the Django framework. We’ll start by setting up the virtual environment for a Django project and configuring it. Then you’ll learn to write reusable pieces of code for your models and find out how to manage database schema changes using South migrations. After that, we’ll take you through working with forms and views to enter and list data. With practical examples on using templates and JavaScript together, you will discover how to create the best user experience. In the final chapters, you'll be introduced to some programming and debugging tricks and finally, you will be shown how to test and deploy the project to a remote dedicated server. By the end of this book, you will have a good understanding of the new features added to Django 1.8 and be an expert at web development processes.
Table of Contents (18 chapters)
Web Development with Django Cookbook Second Edition
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Setting up STATIC_URL dynamically for Git users


If you don't want to refresh the browser cache each time you change your CSS and JavaScript files, or while styling images, you need to set STATIC_URL dynamically with a varying path component. With the dynamically changing URL, whenever the code is updated, the visitor's browser will force loading of all-new uncached static files. In this recipe, we will set a dynamic path for STATIC_URL when you use the Git version control system.

Getting ready

Make sure that your project is under the Git version control and you have BASE_DIR defined in your settings, as shown in the Defining relative paths in the settings recipe.

If you haven't done it yet, create the utils module in your Django project. Also, create a misc.py file there.

How to do it…

The procedure to put the Git timestamp in the STATIC_URL setting consists of the following two steps:

  1. Add the following content to the misc.py file placed in utils/:

    # utils/misc.py
    # -*- coding: UTF-8 -*-
    from __future__ import unicode_literals
    import subprocess
    from datetime import datetime
    
    def get_git_changeset(absolute_path):
        repo_dir = absolute_path
        git_show = subprocess.Popen(
            'git show --pretty=format:%ct --quiet HEAD',
            stdout=subprocess.PIPE, stderr=subprocess.PIPE,
            shell=True, cwd=repo_dir, universal_newlines=True,
        )
        timestamp = git_show.communicate()[0].partition('\n')[0]
        try:
            timestamp = \
                datetime.utcfromtimestamp(int(timestamp))
        except ValueError:
            return ""
        changeset = timestamp.strftime('%Y%m%d%H%M%S')
        return changeset
  2. Then, import the newly created get_git_changeset() function in the settings and use it for the STATIC_URL path, as follows:

    # settings.py
    # … somewhere after BASE_DIR definition …
    from utils.misc import get_git_changeset
    STATIC_URL = "/static/%s/" % get_git_changeset(BASE_DIR)

How it works…

The get_git_changeset() function takes the absolute_path directory as a parameter and calls the git show shell command with the parameters to show the Unix timestamp of the HEAD revision in the directory. As stated in the previous recipe, we pass BASE_DIR to the function as we are sure that it is under version control. The timestamp is parsed; converted to a string consisting of year, month, day, hour, minutes, and seconds; returned; and included in the definition of STATIC_URL.

See also

  • The Setting up STATIC_URL dynamically for Subversion users recipe

  • The Creating the Git ignore file recipe