Is there a way to use this getDiscriminatorModelForClass function with an Array of objects?
This is an Example on the website, but basically i want to abb more than one event to one ClickEvent class. Is this possible?
// The Base Class
class Event {
#prop({ required: true })
public name!: string;
}
// A Discriminator Class Variant
class ClickEvent extends Event {
#prop({ required: true, default: 0 })
public timesClicked!: number;
}
const EventModel = getModelForClass(Event);
const ClickEventModel = getDiscriminatorModelForClass(EventModel, ClickEvent);
Related
export class ChildMessageRenderer implements ICellRendererAngularComp {
public params: any;
#ViewChild(SecComponent, { static: false }) accComponent: SecComponent;
agInit(params: any): void {
this.params = params;
}
public loadRequestsHistory() {
this.params.context.AccountBatchAuditComponent.loadRequestsHistory('36');
}
}
I am trying to call method of SecComponent from ChildMessageRenderer. #ViewChild is throughing error in the console. Can someone help on this issue?
Object structure look like as below:
export class Recipe {
public name: string;
public description: string;
public imagePath: string;
constructorn(name: string, desc: string, imagePath: string) {
this.name = name;
this.description = desc;
this.imagePath = imagePath;
}
}
And my call statement:
export class RecipeListComponent implements OnInit {
recipes: Recipe[] = [
new Recipe('Test Recipe', 'This is simply a test',
'https://cdn.pixabay.com/photo/2016/06/15/19/09/food-
1459693_960_720.jpg')
];
}
Though I am passing all the parameter but still I am getting the error "Supplied parameters do not match any signature of call target"
You misspelled constructor and might want to use parameter properties.
export class Recipe {
constructor(public name: string, public desc: string, public imagePath: string) {
// Insert logic..
}
}
This should do the job.
In my code I often have to copy data from json to instantiate class in constructor.
function append(dst, src) {
for (let key in src) {
if (src.hasOwnProperty(key) {
dst[key] = src[key];
}
}
};
export class DataClass {
id: number;
title: string;
content: string;
img: null | string;
author: string;
// no methods, just raw data from API
}
export class AdoptedClass1 extends DataClass {
// has same fields as DataClass
showcase: string;
constructor (data: DataClass) {
append(data, this);
// do some stuff
}
}
// similar code for AdoptedClass2
I'm wondering if I can replace append function call in constructor with object spread operator
For your need I'll prefer to use Object.assign(this, data) over your custom made append function. Nevertheless have a look at the documentation to understand the limitation of it.
Back to your main question: it is not possible to use the spread operator to do what you want. Many people are interested in that feature but it has been put on hold as you can see here.
To get closer of what you ask we can refactor your code a little:
export class DataClass {
id: number
title: string
content: string
img: null | string
author: string
constructor(data: DataClass) {
Object.assign(this, data)
}
}
export class AdoptedClass1 extends DataClass {
showcase: string
constructor (data: DataClass) {
super(data)
// do some stuff
}
}
By simply adding the constructor to the data class you will be allowed to use super(data) in children and IMHO the code will be a lot cleaner.
You can use object spread operator by replacing this line:
append(data,this)
with this line
data = {...data, ...this};
Suppose I have this class and interface
class User {
name: string;
age: number;
isAdmin: boolean;
}
interface IUser {
name: string;
age: number;
}
And then I get this json object from somewhere
const data = {
name: "John",
age: 25,
isAdmin: true
}
I want to subset data using IUser and remove the isAdmin property like this
let user = subset<IUser>(data);
// user is now { name: "John", age: 25 }
// can safely insert user in the db
My question is how do I implement that function in TypeScript?
function subset<T>(obj: object) {
// keep all properties of obj that are in T
// keep, all optional properties in T
// remove any properties out of T
}
There's no way to do that which is better than:
function subset(obj: IUser) {
return {
name: obj.name,
age: obj.age
}
}
The typescript interfaces don't exist at runtime (which is when subset is invoked) so you cannot use the IUser interface to know which properties are needed and which aren't.
You can use a class which does "survive" the compilation process but:
class IUser {
name: string;
age: number;
}
Compiles to:
var IUser = (function () {
function IUser() {
}
return IUser;
}());
As you can see, the properties aren't part of the compiled output, as the class members are only added to the instance and not to the class, so even a class won't help you.
You can use decorator and metadata (more on that here) but that sounds like an overkill for your scenario.
Another option for a more generic subset function is:
function subset<T>(obj: T, ...keys: (keyof T)[]) {
const result = {} as T;
keys.forEach(key => result[key] = obj[key]);
return result;
}
let user1 = subset(data, "name", "age");
let user2 = subset(data, "name", "ag"); // error: Argument of type '"ag"' is not assignable to parameter of type '"name" | "age" | "isAdmin"'
I'm trying to use the createjs EventDispatcher as a way to dispatchEvents from a class. I'm extending my class using createjs.EventDispatcher and using the dispatchEvent to trigger the event.
I get the following error when this line isthis.dispatchEvent(createJSEvent); executed:
Uncaught InvalidStateError: Failed to execute 'dispatchEvent' on 'EventTarget': The event provided is null.
Simplified TypeScript code to demonstrate what I'd like to do:
export class deviceOrientation extends createjs.EventDispatcher {
constructor() {
super();
// wait 2 seconds and then fire testDispatch
setTimeout(this.testDispatch(), 2000);
}
testDispatch():void {
var createJSEvent:createjs.Event = new createjs.Event("change", true, true);
this.dispatchEvent(createJSEvent);
}
}
// This is the starting function
export function appExternalModuleTest(): void {
let _deviceOrientation: deviceOrientation;
_deviceOrientation = new deviceOrientation();
_deviceOrientation.addEventListener("change", () => this.changeOrientation());
//_deviceOrientation.on("progress", () => this.changeOrientation());
}
export function changeOrientationi(event: Event): void {
console.log('orienationHasChanged ');
}
I'm using easeljs-0.8.1.min.js
I'm not sure if this is possible with CreateJS. Is there a better approach?
Any help is greatly appreciated.
The problem looks strange, because I do almost the same in my project and don't have any problems.
In a nutshell, I have a d.ts file for createjs classes declaration and I use these declarations in my "normal" typescript classes.
For example:
d.ts:
declare module createjs
{
export class EventDispatcher
{
addEventListener(type: string, listener: any, useCapture?: boolean): void;
removeEventListener(type: string, listener: any, useCapture?: boolean): void;
removeAllEventListener(type?: string): void;
dispatchEvent(event: Event): boolean;
}
export class Event
{
public type: string;
public target: any;
public currentTarget: any;
constructor(type: string, bubbling?: boolean, cancelable?: boolean);
clone(): Event;
}
}
Normal class:
module flashist
{
export class TestEventDispatcher extends createjs.EventDispatcher
{
public constructor()
{
super();
}
public testDispatch(): void
{
var tempEvent: createjs.Event = new createjs.Event("test");
this.dispatchEvent(tempEvent);
}
}
}
And somewhere else in the code you should create an instance of the TestEventDispatcher class. Something like:
this.testDispatcher = new TestEventDispatcher();
this.testDispatcher.addEventListener("test", (event: createjs.Event) => alert("Test Event Listener"));
this.testDispatcher.testDispatch();
I've just tested the code and it works for me.
The only idea I have is to make sure that the easel.js file is loaded before your main app files.