You can use a Step Builder if you have many mandatory parameters. In short: you define an interface for every single mandatory parameter and a builder method returns the next mandatory builder interface or the builder itself for optional methods. The builder remains a single class which implements all the interfaces. interface StepB { StepBuilder … Read more
You should use groupby. In Query Builder you can do it this way: $users = DB::table(‘users’) ->select(‘id’,’name’, ’email’) ->groupBy(‘name’) ->get();
This is certainly possible with the recursive bound, but the subtype builders need to also be generic, and you need a few interim abstract classes. It’s a little bit cumbersome, but it’s still easier than the non-generic version. /** * Extend this for Mammal subtype builders. */ abstract class GenericMammalBuilder<B extends GenericMammalBuilder<B>> { String sex; … Read more
Here’s a minimal reproduction: #[derive(Debug)] pub struct Canvas; impl Canvas { fn new() -> Self { Canvas } fn color(&self) -> &Canvas { self } } fn main() { let mut canvas = Canvas::new().color(); // 1 ^~~~~~~~~~~~~ // 2 ^~~~~ println!(“{:?}”, canvas); } Rust 2015 error[E0597]: borrowed value does not live long enough –> src/main.rs:15:22 … Read more
If you wanted to avoid an eval(), you could just do: id = “1234asdf” constructor = globals()[id] instance = constructor() Provided that the class is defined in (or imported into) your current scope.
FutureBuilder removes boilerplate code. Let’s say you want to fetch some data from the backend on page launch and show a loader until data comes. Tasks for ListBuilder: Have two state variables, dataFromBackend and isLoadingFlag On launch, set isLoadingFlag = true, and based on this, show loader. Once data arrives, set data with what you … Read more
Instead of getApplicationContext(), just use ActivityName.this.