Tech Blog

Here I'll be sharing insights from my professional experiences and studies in data science and web development. There'll be plenty of Wagtail, Django and Python, a bit of JavaScript and CSS thrown in, and more on data science & engineering. There might even be a bit of time for some project management and business analysis too.

I'll also provide insights into how this site was made, as well as code examples and thoughts on how those could be further developed.

Feel free to leave questions or comments at the bottom of each post - I just ask people to create an account to filter out the spammers. You won't receive any unsolicited communication or find your email sold to a marketing list.

 
Importing Text From File Into a textarea HTML Form Field

Importing Text From File Into a textarea HTML Form Field

This article covers how to add the ability to read the contents of a text file into a textarea form field from the front end without need to upload anything to the server. We'll go through adding a file input button with file type filter, enabling drag/drop and setting up the necessary JavaScript to handle both events.

We'll tie this together by creating a custom FieldPanel in Wagtail's CMS and add some CSS to tidy things up.
2023-05-23 10:20:50 UTC
Wagtail - Creating Custom Choosers with Viewsets

Wagtail - Creating Custom Choosers with Viewsets

Wagtail has a number of basic views for common activities like generating / modifying model instances and chooser modals. Because these frequently involve several related views with shared properties, Wagtail also implements the concept of a viewset, which allows a group of views to be defined and their URLs to be registered with the admin app as a single operation.

This article demonstrates how to create a custom chooser modal for the User model and add responsive filtering to search for records based on a defined set of columns.
2023-04-18 11:23:46 UTC
Add Unaccent Support in PostgreSQL Search

Add Unaccent Support in PostgreSQL Search

PostgreSQL has a some pretty useful NLP search capabilities out of the box. However, PostgreSQL search backends will only load the character set native to the language you've set your backend to use. Accented words on an English site won't be searchable with unaccented terms for example.

I show a quick way to load the full extended character set into a custom backend and take you through how to verify that the search is indexing and returning results as desired from the command prompt. Finally, I'll use the custom backend for my Wagtail site search to return pages with unaccented queries.
2023-01-08 00:01:22 UTC
Wagtail: Extending the Draftail Editor Part 4 - Custom Lists

Wagtail: Extending the Draftail Editor Part 4 - Custom Lists

The fourth part of this series looks at creating custom lists in Draftail, including the limitations considering this is not currently a supported feature in the editor.

I'll show how to create custom list styles within those limitations, and also how you can use a custom list to apply styling around a group of consecutive blocks of the same type.
2022-12-29 19:06:17 UTC
Configuring a Dynamic Sitemap on Wagtail

Configuring a Dynamic Sitemap on Wagtail

A sitemap lists a website’s most important pages, making sure search engines can find and crawl them. It's important to keep your sitemap up to date for optimal SEO.

With a quick bit of coding, you can set your sitemap to be created dynamically on demand, ensuring it always reflects the latest content.

We'll go through adjusting the lastmod field, and add values for the changefreq and priority on site, class or page level.

I'll show you how to add support for xhtml alternate entries for multi-lingual sites using a custom view in place of the built-in Wagtail sitemap app.

Finally, I add a method to notify Google of updates automatically on page publish/delete.
2022-12-22 18:25:06 UTC
Making Wagtail pages more SEO friendly with Wagtail Metadata

Making Wagtail pages more SEO friendly with Wagtail Metadata

Wagtail pages are great for creating a lot of rich content straight out of the box, but for SEO optimization, they need some tweaking.

Here, I subclass the Page model with some help from the wagtail-metadata plug-in.

This subclassed model becomes the base for all site pages and holds all the data for og metadata, twitter cards, page description etc..
2022-12-22 18:24:27 UTC
Improve Response Times and SSL Security on Your NGINX Web Server

Improve Response Times and SSL Security on Your NGINX Web Server

NGINX is a lightweight and fast web server that meets the content delivery needs of most small to medium sites. Loading speed is now a crucial metric in how the search engines rank websites.

With a little basic configuration you can vastly improve the performance of your server and reduce delivery times. Here, I give an introduction to enabling HTTP/2, gzip compression and cache headers.

We'll also add a few changes to tighten SSL security with a stronger ciphers list, Strict Transport Security (HSTS) and add a CAA record to our DNS.
2022-12-22 16:49:22 UTC
Create Thumbnails with Preserved Edges Using Python Image Library

Create Thumbnails with Preserved Edges Using Python Image Library

The Python Image Library (Pillow or PIL) has a host of image processing methods available to create images on-the-fly.

If you ever had the annoyance of uploading an image to a website, only to have it cropped to fit a certain aspect ratio, then this article is for you. I walk through creating thumbnails where the entire image is displayed without cropping or stretching while meeting the thumbnail dimension requirements

I'll also go through how to add this as an image filter in Wagtail so you can create thumbnail renders for your metadata.
2022-11-04 17:43:59 UTC
Creating Responsive Font Sizes Based on the Viewport

Creating Responsive Font Sizes Based on the Viewport

Previously, responsive typography required a series of media queries, font definitions, and other complexities. All of that has changed thanks to widespread browser support for variable fonts and the all-important CSS clamp() function.

I'll show you how to linearly scale text between a set of minimum and maximum sizes when the width of the viewport changes, with the goal of making its behaviour at different screen sizes more predictable without the use of media queries and with only one line of CSS. Use the on-screen calculator to build your font sizes.
2022-10-25 12:03:16 UTC
Wagtail: Extending the Draftail Editor Part 3 - Dynamic Text

Wagtail: Extending the Draftail Editor Part 3 - Dynamic Text

In this third part of extending the Draftail editor, I introduce a way to add dynamic inline text to your rich text blocks using a combination of dummy css class definition and JavaScript rather than the overly complicated entity route.

I'll go through an example of adding inline Font Awesome icons as a proof of concept which could be easily adapted to show any dynamic information such as stock indices, exchange rates, availability of a resource etc..
2022-10-21 11:14:38 UTC
Wagtail: Extending the Draftail Editor Part 2 - Block Styles

Wagtail: Extending the Draftail Editor Part 2 - Block Styles

The second part of this series looks at customising and adding block styles to the Draftail rich text editor.

We walk through customising the blockquote style, add text alignment buttons to the editor as an example and then consider a different way to accomplish this outside of the editor with a StructBlock and why that might be preferable.
2022-10-13 11:31:01 UTC
Wagtail: Extending the Draftail Editor Part 1 - Inline Styles

Wagtail: Extending the Draftail Editor Part 1 - Inline Styles

This article discusses how to create custom inline font styles not included by default in the Draftail rich text editor.

I'll include adding tag-based styling (such as <u>), how to add styled <span> tags and also demonstrate using both unicode glyphs and svg paths for your toolbar icon.
2022-10-05 12:50:13 UTC