React and TypeScript, how to properly define direct properties of my component class?

React and TypeScript, how to properly define direct properties of my component class?

typescript react component type
typescript react component as prop
react typescript
typescript react-dom element
react ref typescript
typescript react ref object is possibly null
react component interface
react ref functional component

I've just started working with TypeScript and I ran into an error. Often I initialize refs in my constructor but TypeScript doesn't like it, consider this:

class MyComponent extends React.PureComponent<types.MyComponentProps>
  constructor(props: MyComponentProps){
    super(props);

    // error here: Property 'target' does not exist on type 'MyComponent'
    this.target = React.createRef(); 
  }
}

I know that React.PureComponent accepts an argument for props and an argument for state but how can I let TypeScript know that my component should expect properties directly, such as refs? Or alternatively, is this an anti-pattern and should I be defining refs differently?


You should initialize target as a class property:

class MyComponent extends React.PureComponent<types.MyComponentProps>
  target = React.createRef(); 

  constructor(props: MyComponentProps){
    super(props);
    // May not need a constructor at all
  }
}

How to extend React.Component interface with a “direct” property , class MyComponent extends React.PureComponent<types.MyComponentProps​> constructor(props: MyComponentProps){ super(props); // error here: Property  Class Component. Let's start with the class component. A class component is created by extending React.Component<P, S>. Defining properties' shape. React.Component<P, S> is a templated class. P defines the shape of your properties, while S on the other hand defines the shape of the component's state. So lets say we want to define a component for a TodoItem.


This is the way I do it, this way you get all the necessary type information for your ref. For example: a ScrollView

interface Props {}

interface State {}

class SomeComponent extends React.PureComponent<Props, State> {

  private target: React.RefObject<ScrollView>; // or some other type of Component

  constructor(props: Props){
    super(props);

    this.target = React.createRef(); 
  }

  public render(): JSX.Element {
    return (
      <ScrollView ref={this.target}>
        ...
      </ScrollView>
    );
  }

  // now you can define a scrollToTop method for instance
  private scrollToTop = (): void => {
    // The scrollTo method is available from autocomplete since it was defined as a ScrollView ref
    this.scrollViewRef.current.scrollTo({ x: 0, y: 0, animated});
  }
}

TypeScript and React: Components, You should initialize target as a class property: class MyComponent extends React.PureComponent<types.MyComponentProps> target = React.createRef();  The “olde way” of doing components is with class components. And they can keep state per class. State is like props, but private and only controlled by the component. @types/react typings of course have full support for those, and are also equally easy to use. Class components need to be extended from the base React.Component class.


You are declaring target in the constructor which is wrong, do it like this

class MyComponent extends React.PureComponent<types.MyComponentProps>
  constructor(props: MyComponentProps){
    super(props);

  }
this.target = React.createRef();
}

typescript-cheatsheet, I just had to declare the class property with the Typescript way : export default class TextField I use a higher order component with Typescript 2.8 in my codebase: const How do I properly set types on the component to let users of the wrapped to react component while also having required props defined in an interface. Just like React class components, whether the component has a state or not is still up to us. The latest React TypeScript definition gives you the choice between the following two new identical types.


Working with React and TypeScript, Functional components; Stateful class components; defaultProperties. Functional components #. Functional components are my most favourite thing in React. Creating a type for our properties, and telling TypeScript that the parameters of our we can use children even though we haven't defined them in our CardProps Create a Class Component. When creating a React component, the component's name must start with an upper case letter. The component has to include the extends React.Component statement, this statement creates an inheritance to React.Component, and gives your component access to React.Component's functions.


JSX In Depth – React, In TypeScript, all newly declared object properties (including both function example above is compiled successfully is because the compiler assumes age can only be of Exporting an interface for a react.js class component's state: and are a powerful way of defining contracts within your code as well as contracts with  Typically, new React apps have a single App component at the very top. However, if you integrate React into an existing app, you might start bottom-up with a small component like Button and gradually work your way to the top of the view hierarchy. Extracting Components . Don’t be afraid to split components into smaller components.


Web Components – React, Developing React components with TypeScript; 5. by the TypeScript compiler to ensure that we are using the third party libraries correctly. boolean } // Defines the interface of the properties of the TodoItem component interface namespace app.miscelanious { export class Utils { // generates a new  There are lots of possibilities for use cases, parsing date objects, checking lengths of arrays, if properties exist on an object you passed through, and so forth. With TypeScript. Let’s move away from our ES5 example and convert this over to a TypeScript class.