👋🏼Hey!

I am Daniel, a research associate passionate about app development for  iOS and web development with React. Below you can find some of my blog posts, products and projects, as well as ways to connect with me.

💎Products

The icon of the iOS app Mind the Focus showing a purple moon on a white backgroundMind the Focus — calendar-based focus automation

Looking to link and automate your focus with your calendar? Mind the Focus does that for you, so you don’t have to worry about it! As a productivity app, Mind the Focus synchronizes with your calendar, prompting you just at the right time to activate the desired focus for your next event.

Download on the App Store

The icon of the iOS app catalyst showing a three-dimensional, orange rendering of the letter C on a purple backgroundcatalyst

A native iOS client for GitLab that helps you with project management, tackling issues, and staying on top of your TODOs with notifications — across different instances of GitLab.

Download on the App Store

The logo of Educative IncorporatedLearning Advanced Concepts of SQL with MySQL

A course about advanced concepts of SQL with interactive playgrounds using MySQL.

The icon of the theme gust showing an abstract symbol of a wind gustGust

A minimalistic theme for blogs and personal websites built with Next.js, MDX, and Tailwind CSS. Provides developer-first experience with rich components.

🖋️Articles

Link iOS Sleep Schedule with Hue Light Bulbs using Shortcuts and Hue API

iOS
Shortcuts

An iOS shortcut to link the sleep schedule with the Hue light bulbs through the Hue API.

Deploying Multi Zones on Vercel with Next.js

Web Development

Next.js and Vercel offer support for multi zones that merge different deployments in a single project. Assigning custom domains to all zone in Vercel is crucial to encourage search engines to index each deployment.

Open Third-Party URLs in a SwiftUI App Using a Share Extension

iOS
SwiftUI

There are two widespread ways of opening an URL with a SwiftUI app, namely custom URL schemes and universal links. Since the latter are not applicable for third-party URLs, I utilize a share extension combined with a custom URL scheme to open third-party URLs in a SwiftUI app.

Infinite Scrolling List for Paginated Results from GraphQL with SwiftUI

iOS
SwiftUI

Creating a list in SwiftUI is pretty simple. To populate lists, we usually refer to other data sources, e.g., an API. This way, the items in the list can easily exceed the available vertical display space which automatically makes the list scrollable. However, the API used as the list’s data source may not return all items that satisfy the corresponding request. Rather, the returned results are paginated where only one of the pages is returned at a time. To enable the user to scroll through the list of all items seamlessly, we refer to the paradigm of infinite scrolling.

Tackling AttributeGraph precondition failure: setting value during update using Realm in SwiftUI

iOS
Realm
SwiftUI

In SwiftUI, AttributeGraph precondition failure is a common error that often hints at an underlying issue. In this article, we look at an instance of this error occurring when using Realm's @ObservedResults property wrapper.

Synced Realm on iOS with SwiftUI using Sign-in with Apple for Authentication

iOS
Realm
SwiftUI

Some apps store sensitive user information that requires authorized access. For example, an app may store a user’s first and last name which should not be accessed by any other user. As such, these apps need to integrate with authorized data storage. On iOS, two commonly employed technologies for authentication and authorized data storage are Sign-in with Apple and Realm, respectively.

Updating Schema of Synced Realm and iOS App in Production

iOS
Realm

Realm offers a development mode to conveniently design your app’s data models from its source code. Once the app enters the production environment, updating the app’s data models becomes more involved. This article shows you how to perform such a schema update in a synchronized Realm and iOS.

Security Vulnerability in GitLab: Sending Arbitrary Requests through Jupyter Notebooks

Security

With GitLab 14.3, the DevOps platform fixed a security vulnerability that enabled an attacker to impersonate a victim while sending arbitrary HTTP requests. Exploiting this vulnerability would allow an attacker to gain maintainer access to a third-party project, for example. This exploit was possible due to a stored XSS vulnerability in the rich representation of Jupyter notebooks. Combining the lack of HTML sanitization with an npm package used by GitLab triggered an arbitrary HTTP request on behalf of the victim, impersonating them.

Migration of a dockerized MySQL database with SQLAlchemy and Alembic

SQL

The data models in a database evolve with the development of a codebase. Hence, applying changes to these data models is a common task of developers. While tools like SQLAlchemy and Alembic come in handy to accomplish these tasks, using Docker for the development process adds another layer of challenges on top. In this article, I showcase the migration of a dockerized MySQL database in Python with the aforementioned tools.

How busy is your gym? A home screen widget for iOS

iOS
JavaScript
Shortcuts

A home screen widget for iOS created using Scriptable and JavaScript to display the number of visitors currently at your gym.