Tutorials covering programming languages, type systems, architecture, tooling, and the patterns used to build software that lasts. Each chapter is standalone, built around real examples and verified facts.
Native HTML form elements — <input>, <select>, <textarea> — are integrated into Angular’s forms system through built-in directives called value accessors. When you write formControlName=”email” on an <input>, Angular’s DefaultValueAccessor handles the bridge between the DOM element and the FormControl instance. But the moment you need a control that is not an <input> — a…
These two media features let you adapt styles based on how the app is displayed and the visual capabilities of the screen — from standalone PWA mode to HDR displays. Overview of Features Feature Description Values display-mode How the document is displayed browser, standalone, minimal-ui, fullscreen, picture-in-picture dynamic-range Brightness, contrast, and color depth standard, high…
An exception is a signal that something went wrong. It interrupts the normal flow of the program, unwinds the stack, and transfers control to the nearest handler. Dart’s exception system has four keywords: try, catch, on, and finally. The try block contains the code that might throw. The catch block handles the exception. The on…
A bridge network puts the container behind a NAT. The container has its own IP, but it is on a virtual subnet, and the outside world reaches it only through published ports. Some applications do not accept this. A legacy application that uses broadcast discovery, a monitoring tool that needs to see all traffic, a…
Method overriding is when a subclass provides its own implementation of a method that already exists in its parent class. The subclass’s method “takes over” — when called on an instance of the subclass, the new method runs instead of the parent’s. A Quick Look at the Example a. What is Method Overriding? Method overriding…
An error handler is not the place to fix the error. It is the place to translate the error into a response. The route throws, the error propagates, and the centralized handler receives it. The handler decides the status code, the message, and the format. It logs the error for the operators, and it sends…
Every asynchronous operation has three possible outcomes: it is still running, it succeeded, or it failed. A React component that fetches data must represent all three. The previous chapter introduced the three states as part of the fetch pattern. This chapter treats them as a design problem in their own right: how to model them,…
A function that calls a fallible function must decide what to do with the error. It can handle the error, or it can pass it to its own caller. Handling the error is the match or the unwrap. Passing it is propagation. The ? operator is the shorthand for propagation: it extracts the success value…
The INNER JOIN is the most common join type and the one you reach for by default when you need to combine data from two tables. It returns only the rows where the join condition matches in both tables. Rows with no match in either table are excluded from the result. This behavior is what…
A variant applies a utility based on the element’s own state. The hover: variant applies when the element is hovered. But sometimes the state belongs to a different element. A card’s child should change when the card is hovered. A label should change when the input next to it is focused. A dropdown should open…