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Django’s system check framework provides fantastic protection for configuration mishaps. It’s like a targeted linter that runs when you start Django commands. It takes advantage of runtime setup to inspect the true state rather than infer it from the source.
GeoDjango requires the GDAL and GEOS spatial libraries. On macOS, you can use Homebrew to install these, but they won’t be picked up by default since they live in a non-default library directory, /opt/homebrew/lib. Django will fail to start with an exception:
Mastodon is a Twitter-like social network with a solid Django community presence. It’s a fantastic online arena for connecting with others, discovering news, discussing issues, and sharing FOMO-inducing conference photos.
pre-commit’s “fail” virtual language fails all files that it matches. Combine it with pre-commit’s file name and type matching to block unwanted files in your repository.
I just released a major update to my 2021 book Boost Your Django DX. This update contains new content, a bunch of edits, and uses the latest versions of tools, including Python 3.12 and Django 5.0.
PostgreSQL’s powerful full text search feature supports several query syntaxes. Of these, a website search feature should typically pick the websearch syntax. websearch copies some features from popular search engines, as covered below, offering familiar short syntax to users. It is also forgiving and will never raise a syntax error for user input, whilst other syntaxes can.
My two “Boost Your DX” books are available in a bundle deal, saving $10 compared to buying them separately. Great for improving your Django and Git skills at the same time.
Global Privacy Control (GPC) is a specification for web browsers to signal website operators not to share or sell the user’s data. This signal is intended to exercise legal data privacy rights such as those provided by the California Consumer Privacy Act (CCPA) or the EU’s General Data Protection Regulation (GDPR). While GPC is a proposal, support has been implemented in Firefox and several other privacy-focused browsers and extensions.
A fairly common situation in a Django project is where you need to store and serve arbitrary HTML fragments. These often come from forms with rich text editors (using HTML’s contenteditable).
This evening I held a quiz at the December London Django Meetup Group. The quiz is a regular tradition: this was the fifth quiz that I’ve presented, and the sixth overall.
Some models have one or a few large fields that dominate their per-instance size. For example, take a minimal blog post model:
URLField.assume_scheme warningsSince Django’s inception, the web has gradually moved from HTTP to HTTPS, a welcome move for security. But the history has meant older parts of Django have had a lingering HTTP bias. Many of these have been migrated to default to HTTPS instead in previous versions. Django 5.0 starts the migration of another, tiny HTTP bias in forms.URLField.
Here are some Django-related deals for this year’s Black Friday (24th Nov) and Cyber Monday (27th Nov), including my own.
runserver with lsofIf you start runserver but your terminal session gets closed, the server can continue running in the background. For example, this can happen when your IDE crashes. This situation is annoying because you can’t stop the backgrounded runserver with Ctrl-C.
Here’s a write-up of an optimization I made in my client Silvr’s project. I ended up disabling a PostgreSQL feature called the JIT (Just-In-Time) compiler which was taking a long time for little benefit.
I released Boost Your Git DX nearly two weeks ago. It’s the second in my “Boost Your DX” series, following last year’s Boost Your Django DX. Both books aim to improve your development experience with their respective tool.
I’ve once more had the pleasure of joining Carlton and Will on the Django Chat podcast, in Episode #146. We spoke on Tuesday, just hours after Django 5.0 alpha 1 was released, on several topics:
Django’s template engine has an underappreciated builtins option that selects libraries to preload in every template. Making a library a builtin avoids the need for an explicit {% load %} tag whenever you use its tags or filters. Putting key libraries in builtins can shorten your templates and make development a little bit faster.
string_if_invalid in templatesDjango’s template engine has a string_if_invalid option that replaces missing variable lookups with a string of your choice:
As projects evolve, old functionality gets removed. Often such deletions are incomplete, leaving in their wake unused functions, classes, and other code objects. Unused code is clutter that brings no joy: it hinders comprehension, taxes codebase-wide quality improvements, and can sometimes lead to errors if later used.
QuerySetsSometimes code depends on the order of a QuerySet whilst not specifying an order. This can lead to random, flaky test failures because databases can return rows in any order when none is specified. The problem is made worse by some databases, notably PostgreSQL, which nearly always return rows in insert order, but occasionally use a different order when a table has had recent deletions.
json_script for pre-serialized JSON stringsDjango’s json_script template filter is a convenient and safe way to pass a larger amount of data to JavaScript. I covered it in my post last year How to Safely Pass Data to JavaScript in a Django Template.
format_html()Can you spot the problem with this Django snippet?
Django’s template engine allows you to augment template contexts with context processors. These are functions that take the current request and return a dictionary to be merged into the context:
Here’s an application of “test smarter, not harder”, as per Luke Plant’s post. I came up with this recently whilst working on my client Silvr’s project, and I’m pretty proud of it. It should apply to any project using Django’s admin.