Rob Allen's DevNotes – Developing software in the Real World

Dark and light mode blog images with MarsEdit

As dark mode is more popular than ever now that the iPhone supports it, I've been working out how to get the browser to render a dark image in dark mode and a light image in light mode. It turns out that the way to do this simply is to use the <picture> element like this:

<picture>
    <source 
        srcset="/wp-content/uploads/2019/11/example-image-dark.png"
        media="(prefers-color-scheme: dark)"
    />
    <source
        srcset="/wp-content/uploads/2019/11/example-image-light.png"
        media="(prefers-color-scheme: light), (prefers-color-scheme: no-preference)"
    />
    <img src="/wp-content/uploads/2019/11/example-image-light.png" 
         alt="Description of example image here"
         class="border" loading="lazy" />
</picture>

1

2

3

4

5

6

7

8

9

10

11

12

13

<source

srcset="/wp-content/uploads/2019/11/example-image-dark.png"

media="(prefers-color-scheme: dark)"

/>

<source

srcset="/wp-content/uploads/2019/11/example-image-light.png"

media="(prefers-color-scheme: light), (prefers-color-scheme: no-preference)"

/>

<img src="/wp-content/uploads/2019/11/example-image-light.png"

alt="Description of example image here"

class="border" loading="lazy" />

</picture>

As I use MarsEdit to write my posts, I created a Media Markup Template that does the heavy… continue reading.

Posted on 4 December 2019 in Computing, MarsEdit, Software Leave a comment

Cannot find zlib headers on macOS 10.15 Catalina

My new MacBook Pro 16" comes with Catalina and while setting up Python to develop rst2pdf, I discovered that Pillow wouldn't install.

    Running setup.py install for pillow ... error
    ERROR: Command errored out with exit status 1:

1 2	Running setup.py install for pillow ... error ERROR: Command errored out with exit status 1:

Looking through the long list of red text I came across:

    The headers or library files could not be found for zlib,
    a required dependency when compiling Pillow from source.

1 2	The headers or library files could not be found for zlib, a required dependency when compiling Pillow from source.

Aha! The way this was solved on the previous version of macOS (Mojave) was to use the macOS_SDK_headers_for_macOS_10.14.pkg installer to set up symlinks to header files from the old place to the new place. This doesn't work on Catalina, so… continue reading.

Posted on 27 November 2019 in Python, rst2pdf Leave a comment

Changing an SQL Server primary key in Doctrine Migrations

I recently came across a rather weird quirk when trying to change a primary key in Sql Server using Doctrine Migrations: you need to use two migrations to get it to work. This is incredibly minor and I'm only writing it up as it confused me for a while so I thought that I'd document so that I'll find this article if I run across it again in the future! This is the migration:

final class Version20191023125629 extends AbstractMigration
{
    public function up(Schema $schema) : void
    {
        $table = $schema->getTable('page_category');
        $table->dropPrimaryKey();
        $table->setPrimaryKey(['page_uuid', 'category_id']);
    }

    public function down(Schema $schema) : void
    {
        $table = $schema->getTable('page_category');
        $table->dropPrimaryKey();
        $table->setPrimaryKey(['page_id', 'category_id']);
    }
}

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

final class Version20191023125629 extends AbstractMigration

{

public function up(Schema $schema) : void

{

$table = $schema->getTable('page_category');

$table->dropPrimaryKey();

$table->setPrimaryKey(['page_uuid', 'category_id']);

}

public function down(Schema $schema) : void

{

$table = $schema->getTable('page_category');

$table->dropPrimaryKey();

$table->setPrimaryKey(['page_id', 'category_id']);

}

Posted on 20 November 2019 in PHP Leave a comment

First steps with Windows on Vagrant

One thing that would be useful for one of my projects is an easy way to install IIS, PHP & SQL Server on Windows in a repeatable way. I wasn't sure how to do this until I came across Chocolatey and Boxstarter. Chocolatey is a package manager for Windows along the same lines as yum and apt for Linux and knows how to install a remarkable amount of software. Boxstarter is a way to automate… continue reading.

Posted on 14 November 2019 in Software, Windows Leave a comment

Testing migrating to Laminas

Zend Framework is renaming to Laminas and all the source code is moving to a new GitHub organisation. Implicitly this means a new PHP top level namespace. As you can imagine, this implies that a lot of our code will need to change, so Matthew, Michał and the team have been writing migration tooling to make this easier. It's now time to test it and they need all the help they can get on real-world… continue reading.

Posted on 6 November 2019 in Laminas, PHP, Zend Framework One comment so far

Embedding Notist slides

This site uses WordPress under the hood as I find the flexibility that a good CMS provides quite useful. For the talks section, I use a custom post type so that I can set additional properties on the post and customise the display. With my usual lack of imagination, my custom post type is called talk. When Notist was released, I've been uploading the PDFs for my presentations there so that I have a nicely… continue reading.

Posted on 30 October 2019 in PHP, WordPress Leave a comment

HTML encode selected text on Mac

When writing blog posts, I write directly in HTML, mostly from habit and because I've not set up mark-up text processing on WordPress. I'm comfortable enough with simple HTML that it's never seemed important enough to sort out, especially with MarsEdit's macros for common HTML tags. One thing that I need to do relatively regularly is to HTML encode code snippets for use in <tt> and <pre> tags. I have been doing this via a… continue reading.

Posted on 23 October 2019 in Computing, Keyboard Maestro, MarsEdit Leave a comment

Custom error rendering in Slim 4

One of the nice things about Slim 4 is that it's easier to customise the HTML generated on error without having to worry about the rest of the error handling mechanism. This is because we have separated error rendering from error handling. Slim's default ErrorHandler maintains a list of renderers, one for each content-type and will delegate the creation of the error payload (HTML, JSON, XML, etc) to the renderer. Out of the Box, the… continue reading.

Posted on 16 October 2019 in PHP, Slim Framework, Slim Framework 4 View all 6 comments

Folder types in AppleScript

I've recently moved to Adobe Lightroom Classic for photo editing, but am still using Apple Photos for viewing my photos on my iPhone and iPad. As such, I wanted an easy way to import photos exported from Lightroom into Photos, so I turned to AppleScript. My requirements are that I want to import all the photos in each sub-folder of a root folder called "ToPhotos" into Folders and Albums in Photos that are a child… continue reading.

Posted on 9 October 2019 in AppleScript Leave a comment

Dependency Injection in Slim 4

In contrast with Slim 2 and Slim 3, Slim 4 does not ship with a DI container, but instead, supports any PSR-11 compatibly DI container that you provide. This is part of Slim 4's commitment to interoperability via the PHP-FIG standards. The easiest way to add a container to your Slim application is to call AppFactory::setContainer() before you call AppFactory::create(). The setContainer() method expects any PSR-11 container. Register the container with Slim Let's look at… continue reading.

Posted on 2 October 2019 in PHP, Slim Framework, Slim Framework 4 View all 3 comments