I'm looking for a class that I can easily create new instances from and optionally assign properties using the constructor.
For instance:
class Person {
name: string;
age: number;
constructor(props: {name?: string, age?: number}) {
this.name = props?.name?? "";
this.age = props?.age?? 0;
}
}
const person1 = new Person({name:"Pete"})
Is there a more streamlined approach to achieve this?
If we define "elegant" as having a DRY syntax, then there is little room for improvement. The example below demonstrates how you can streamline the constructor body implementation by utilizing default parameters and a self-referential type modified by the Partial
class Person {
age: number;
name: string;
constructor({ age = 0, name = "" }: Partial<Person> = {}) {
this.age = age;
this.name = name;
}
}
console.log(new Person({ name: "Pete" })); // { age: 0, name: "Pete" }
console.log(new Person({ age: 155 })); // { age: 155, name: "" }
console.log(new Person({ age: 155, name: "Pete" })); // { age: 155, name: "Pete" }
console.log(new Person({})); // { age: 0, name: "" }
console.log(new Person()); // { age: 0, name: "" }
TypeScript also offers parameter properties. However, this concept does not apply to the given example because the single constructor parameter is an object type, which cannot be assigned to any members of the class itself. By restructuring the class constructor to use ordered parameters for each field (instead of an object parameter), you could make use of this syntax pattern.
I'm attempting to create an expanding effect in my navbar using Angular. When I click on "show information," the content should slide up. The issue is that the top part of my footer does not follow the effect. I have tried something like: <foot ...
I am looking to use a more explicit name such as userId instead of the type number in my error message for error types. export const primaryKey: PrimaryKey = `CONSUMPTION#123a4`; // The error 'Type ""CONSUMPTION#123a4"" is not assignable to ...
I am looking to send a value based on a toggle switch checkbox selection between Hourly or Salary. How can I incorporate this into the form below? html <div class="row"> <div class="col-sm-6"> <div cl ...
I'm struggling to figure out how to execute a code snippet for my Angular app on Stack Overflow. Specifically, I am using mat-autocomplete. When I select a name that is 128 characters long, the cursor appears at the end of the selected string instead ...
Below are the components and function I am working with: interface ILabel<T> { readonly label: string; readonly key: T } interface IProps<T> { readonly labels: Array<ILabel<T>>; readonly defaultValue: T; readonly onChange ...
Why isn't the view reflecting changes when a variable is updated within a subscribe function? Here's my code snippet: example.component.ts testVariable: string; ngOnInit() { this.testVariable = 'foo'; this.someService.someO ...
When using the Openlayers Map scale line in Metric units, a specific zoom rate may be repeated twice during the zoom event, even though the actual zoom-in resolution varies on the map. In the provided link, you can observe that the zoom rates of 5km and ...
Can someone assist me with a dilemma I'm facing? Within CRM on Demand, I have a view that needs to extract values from CRM input fields to conduct a search against CRM via web service. If duplicate records are found, the view should display them. Be ...
I have been working on developing an Ionic app that requires creating a session for user login. The goal is to store the user's name upon logging in, so it can be checked later if the user is still logged in. I have created a model class and a user cl ...
Having trouble with promises, I believe I grasp the concept but it's not functioning as expected in my project. Here is a snippet of my code : (I am working with TypeScript using Angular 2 and Ionic 2) ngOnInit() { Promise.resolve(this.loadStatut ...
I'm facing a challenge where I need to transfer a single ion-card from the "drafts" segment to the "sent" segment by simply clicking a button. However, I am unsure of how to achieve this task seamlessly. Check out this image for reference. ...
Within a parent component, there is a list: items: SomeType; The values of this list are obtained from a service: this.someService.items$.subscribe(items => { this.items = items; }); At some point, the list is updated with new criteria: this.some ...
Why bother naming the export if you already have a file with the default export name? This seems redundant and goes against the DRY principle. While there is a rule that discourages anonymous default exports, how can we enforce an error when someone does ...
Recently diving into Angular 6 and facing an issue with my mat-toolbar integrated with mat-sidenav. Everything seems to be functioning fine, but I'm looking to customize the color for the active item in the side nav menu. Currently, all items have a ...
I am encountering an issue with the angular2-seed application. It seems unable to render my css when I place it in the index.html. index.html <!DOCTYPE html> <html lang="en"> <head> <base href="<%= APP_BASE %>"> < ...
I need to set a key value, but only if it doesn't already exist. In my component1.ts file, I am assigning the key and value in the constructor. However, I want to include a condition that this action should only be taken if the key is not already pre ...
SOLUTION STRATEGY: If you encounter a similar issue and are looking for a more comprehensive solution rather than quick fixes, consider recreating the repository. While it involves more effort initially, it can prevent future issues. In my case, the repos ...
Trying to pass request parameters using model structure in typescript. It works fine for non-nested objects, but encountering issues with nested arrays as shown below: export class exampleModel{ products: [ { name: string, ...
Creating a universal function in a file that is not a module: example.ts: function example() {} You can easily call this function from another file, say test.ts, without needing to import the function from example.ts: test.ts: example(); // calling univ ...
this.routeHandler = function () { let stations = ['KSFM', 'KPWM'] let coordinates = []; let allCoords = []; if (Array.isArray(stations) == true) { for (let i = 0; i < fetchRoute().length; i++) { fo ...