The functional component here is getTabContent and as long as it returns JSX values or null, it will be fine. TypeScript はJavaScriptに静的型を付けることができるAltJSです。. Proper TypeScript type for creating JSX element from string A ReactElement type could be considered the primitive definition for other types, such as a JSX.Element or JSX.IntrinsicElements. React reads these objects and uses them to construct the DOM. Nowadays most other libraries that encourage using JSX and support fragments have a similar API shape. TypeScript treats intrinsic, function, and class components differently when figuring out which attributes can be assigned to a JSX expression constructed by these components. typescript react elements . Automatically inserting JSX closing element in TypeScript JSX file Currently, when users type non self-closing JSX tag, they will have to type corresponding closing JSX tag. For almost every .tsx file in my project TS7026: JSX ... React With TypeScript: Typing Components - justacodingblog 2015年9月に登場したTypeScript 1.6では JSX のサポートが搭載され、 .tsx という拡張子を用いることでJSXを含むコードを書いたり型チェック . TypeScript: JSX element type does not have any construct or call signatures. We need to explicitly use a type annotation for the parameter in a named event handler. Hi. Bug Report Search Terms TS7026 no interface JSX.IntrinsicElements exists typescript 4.3 typescript 4.3 breaking changes. Babel ). Wherever possible, TypeScript tries to automatically infer the types in your code. Proper TypeScript type for creating JSX element from ... To enable JSX in TypeScript, first save the file as a .tsx file and modify your tsconfig.json to include: Setting the jsx option to "preserve" means that TypeScript should not process the JSX. DOM Element Button in Phaser 3 with JSX and TypeScript ... TypeScript can infer inline event handler parameter types. In fact, the FC type here is not necessary as type inference will be enough. TypeScript suporta incorporação, verificação de tipo, e compilação de JSX diretamente para JavaScript. Name your files with a .tsx extension Enable the jsx option TypeScript ships with three JSX modes: preserve, react, and react-native. 1. typescript jsx element . If you are returning an array in your Custom Hook, you will want to avoid type inference as . Tabris 2 supports type-safe JSX out of the box with any TypeScript based project. TypeScript supports embedding, type checking, and compiling JSX directly to JavaScript. 2. I found this StackOverflow question about typing the prop, and while I'm thankful for the answer, it seems a little convoluted. react typescript. This includes generic types that can be used to strongly-type event handler parameters by passing the type for element raising the event. Basic usage In order to use JSX you must do two things. Typescript components make it an absolute pleasure for developers to integrate your components into their apps and explore your APIs. Questions: I have a component that I want to default to being rendered as an h2. Summary Your type system exists to tell you when you make a mistake. It also requires you to use a Babel plug-in. Each approach has it's own pros and cons, which we'll discuss later. JSX.Element is handy for restricting your children prop to React element but too limiting for general use. This is a default behavior of TypeScript compiler on JSX namespace. JSX element 'T' has no corresponding closing tag.ts(17008) Cannot find name 'T'.ts(2304) Exploration Defining generic function in TypeScript To resolve the issue, I started with researching on how to properly define a generic function in TypeScript. One advantage of using React with TypeScript is that you can easily type the props of your (function) components. To prevent this, we can extend the available interfaces with our own properties. A Complete Example Preview. 1.) export function Heading ({title }: {title: string . Yes! In the end, I've managed to make it work, but I found the process quite messy, with typescript/npm module system getting in the way to have JSX types extend Mithril types (so that your functions can return mithril-compatible types), etc. When using JSX, a fragment is a type of JSX element that allows us to return multiple child elements. typescript by Tomanator on Sep 15 2021 Comment . AnyAction is a redux type, which extends Action (which have a mandatory property type). For example, the type of a variable is inferred based on the type of its initializer: It takes two parameters, but the second parameter is the optional one, and the first one takes the input which needs to be parsed. StatelessComponent type mentioned in this answer has been deprecated because after introducing the Hooks API they are not always stateless. TypeScriptの型におけるJSXサポートが100%分かる記事. A JSX.Element is an extension of ReactElement that has the type<T> and props<P> implemented as any as you can see in the repository: declare global {namespace JSX {interface Element extends React.ReactElement<any, any> { }}} The type for ReactElement is more strict than in JSX.Element, but they are essentially the same However, I think that with less effort, the compiler could be made more flexible. typescript by Abraham . Standard event types for React are available in @types/react. There are some rules which needs to be taken while using the JSON parse method in TypeScript: 1. In this context, the colon : does not mean a type annotation, it means rebinding the name of a property, like in the following example: In TypeScript 2.8, the compiler will try to look up the JSX namespace based on the location of your JSX factory. Uso básico Para usar JSX, você deve fazer duas coisas. When we first implemented fragments in TypeScript, we didn't have a great idea about how other libraries would utilize them. React: `as` prop to JSX element In React, I want some components to accept an as prop that will determine the top-level element tag in the JSX. We can't use TypeScript's type definitions for events, but the good thing is that React has equivalent type definitions for all its synthetic events. export interface OverloadedElement {. xxxxxxxxxx. The best type of props.children is React.ReactNode. I had to modify the mithril typings (and drop npm @types/mithril), and add a few modules of my own. Typescript provides the necessary tools to define strict types for the React components in your apps along with their props, states, and event handlers. For Array I could get it to work by doing instanceof Array but since JSX.Element is an interface that doesn't work for it.. One way is to check typeof === "object" and assert that as a test for whether it's a JSX.Element or not using user-defined type guards. Wouldn't it be better to define your attributes in an interface then set your . I'd like the consumer to be able to specify a different element if they desire. That's why Vue ships with official type declarations for TypeScript - not only in Vue core, but also for vue-router and vuex as well. If you are the author of the web component you can declare your component as part of JSX's IntrinsicElements, like this: You might think that setting the type of my-element to any is less than ideal, and you'd be right. Nomeie seus arquivos com extensão .tsx Ativar a opção jsx TypeScript vem com três modos JSX: preserve, react, e react-native . * This is mainly for the use of the `Reducer` type. Option 1: Type Definitions in the web component. I think you don't get it. export interface Action<T = any> { type: T } /** * An Action type which accepts any other properties. Currently, when TypeScript uses JSX, it looks up a global JSX namespace to look up certain types (e.g. JSX TypeScript. In this situation, our language service can help the users by automatically insert the corresponding JSX tag. typescript by Anxious Antelope on Dec 26 2020 Comment . The solution. This is from the current redux types file. Introduction. TypeScript memiliki tiga jenis mode JSX: preserve, react, dan react-native . There are multiple ways in which this can be handled. React event types. First, install the jsx-dom library that will convert JSX to DOM elements instead of React components. For example, if your JSX factory is React.createElement, TypeScript will try to first . Declare a React functional component of the type React.FC that expects the above props as follows:-. Tags: types, typescript TypeScript Support. You define elementType as string, however, when you actually use it, it becomes a JavaScript expression. For now, here's a demonstration of some of the types you can expect to encounter in this scenario. Create a TypeScript type or an interface to define props that the component expects to receive. In order to allow custom HTML attributes, you need to define it's typing. ReactElement and JSX.Element are the result of invoking React.createElement directly or via JSX transpilation. TypeScriptは、Reactがこれらを区別するのと同じルールを適用します。 組み込み要素は常に小文字で始まり、値ベースの要素は常に大文字で始まります。 組み込み要素(Intrinsic elements) 組み込み要素はJSX.IntrinsicElementsという特別なインタフェースで参照されます。 TypeScript: TS Playground - An online editor for exploring TypeScript and JavaScript. 23. 100% this. However, I think that with less effort, the compiler could be made more . 1 declare class Component<P> { 2 props: P 3 } typescript. TypeScript doesn't read .jsx files. TypeScript supports the JSX syntax, so you can take advantage of the type checker, IDE autocompletion, and refactoring. P can be any name, there is no rule, but a common naming convention is to use T as the prefix, like TProps. for intrinsic element constructors (lower-case tag name), it looks at the type of the same property name in JSX.IntrinsicElements This is customisable by modifying JSX.IntrinsicElements, JSX.ElementClass.However, the type of an element is always JSX.Element.. Of course more interfaces could be added to the JSX namespace. It goes its own route of providing scoped styles in style properties, without changing anything to original components. React's functional components return either a ReactElement or null. We will type our React component with this interface once completed. Change your TypeScript config so your compiler options allow for extra types: {. Type JSX elements based on createElement function TypeScript currently uses a JSX namespace to type the props of JSX elements. "what's the type of a JSX component?"). In the following, I will show you how to define custom props for a component in connection with already existing props like children.. npm install --save jsx-dom. While TypeScript is a godsend for React developers, its syntax is fairly intimidating to newcomers. JSX element type 'Component' does not have any construct or call signatures. TypeScript can preserve the JSX syntax (in case you want to use another precompiler), replace it with React.createElement, or using a custom factory. We just added Element type and TypeScript now infers the type of each JSX block to be of type Element. I'm working with React 16.2.0, TypeScript 2.7.1, and any is not allowed as a type. We need to look up the type of a jsx expression by actually resolving the jsx factory call, so that we don't create a reference to the global JSX.Element type, which can change shape between react versions (as it needs to in the react 16 upgrade). For our case, we can use this to remap the resolution of react and react-dom to the preact-compat layer, which exposes Preact's JSX implementation, among other Preact types. This feature of TypeScript is called declaration merging. You don't have to use React's PropTypes because TypeScript already has its own typing system.. It should be strict enough to exclude all unwanted values, but not so strict as to exclude wanted values. TypeScript's config has an incredibly powerful option that allows import paths to be remapped to destinations of our choice; the paths option. It has one required property, a function, which will return a ReactElement or null.It has a few optional properties, such as propTypes . This post covers different approaches to strongly-typing this powerful and flexible prop with TypeScript. TypeScript supports the JSX syntax, so you can take advantage of the type checker, IDE autocompletion, and refactoring. string type of course doesn't have any construct or call signature. Do that by expanding HTMLAttributes . We should be very cautious while passing the string to parse inside the method. JSX.Element, on the other hand, is a ReactElement with generic type for props and type being any. // which gives you a chance to write, share and learn TypeScript. // to create a simple app with React and Typescript npx create-react-app yourProjectName --template typescript // to add Typescript in an existing project npm install --save typescript @types/node @types/react @types/react-dom @types/jest. A static type system can help prevent many potential runtime errors, especially as applications grow. The React.FC typing is done similar to what we will see here. Tailor this more specifically to your use case if possible. Custom JSX Factories. Your second point is the same as my second note, i.e. It is just a syntactic sugar for React.createElement, which is a JavaScript expression. Or let Typescript infer the type. In the signature ({state: S, props: P, nextJsx}) => JSX.Element, S and P are not types, they are identifiers. With this knowledge in mind, now let's take a look at why TypeScript complains. Posted by: admin November 24, 2021 Leave a comment. 1. A function component is of type React.FunctionComponent and it has an alias React.FC to keep things nice and short.. In this situation, our language service can help the users by automatically insert the corresponding JSX tag. Jest modifies mocked modules at runtime, it does so in a way that leaves the mocked module compatible with its original type but wraps everything to provide mock utility methods such as mockImplementation. When using JSX, a fragment is a type of JSX element that allows us to return multiple child elements. It can also be React.ReactChild, React.ReactChild[], JSX.Element[], JSX.Element but these types have some flaws, for example, JSX.Element[] doesn't accept strings. And it gets at an important little quirk of the way Jest and TypeScript interact. that typeof === "function" doesn't strip the object type. JSX.Element is a ReactElement, with the generic type for props and type being any. Which means you have to use TypeScript as a babel plug-in. It is just a syntactic sugar for React.createElement, which is a JavaScript expression. What is the difference between JSX.Element, ReactNode and ReactElement? Mode tersebut hanya berlaku untuk stage, sedangkan untuk pemeriksaan tipe, hal itu tidak berlaku. 1 Source: www.typescriptlang.org. JSX.Element is the most restrictive type you can use for children. dispatch should accept parameter of type AnyAction. JSX is kept as the output's part by preserve mode. Per the arguments in this issue, React.FC should generally be avoided: On top of that, TS infers that your component is already returning a JSX.Element, so you don't even need to declare that return type. The code below results in the error: We also need to resolve the sfc return type and class element type from the parameters of the factory function overloads for the same reasons . -- CODE language-jsx keep-markup --. You can then use JSX expressions to create widgets. The last option allows you to use JSX without using React, as long as you . // - A location to learn TypeScript where nothing can break. You can read this syntax out loud as "Component of P" where P will be the props type substituted where referenced within the class definition. We just added Element type and TypeScript now infers the type of each JSX block to be of type Element. TypeScript works in three JSX modes. This is a default . Nowadays most other libraries that encourage using JSX and support fragments have a similar API . JSX.Element is resolved via the JSX Factory. The FC type will allow you to use the children prop though but some devs like to always type with FC so each component is already typed. React native mode is somewhat same as the preserve mode. Name your files with a .tsx extension Enable the jsx option TypeScript ships with three JSX modes: preserve, react, and react-native . This is customisable by modifying JSX.IntrinsicElements, JSX.ElementClass.However, the type of an element is always JSX.Element.. Of course more interfaces could be added to the JSX namespace. With this knowledge in mind, now let's take a look at why TypeScript complains. Doing this lets Babel take control of everything JSX and TypeScript stick to types as it does not yet support Vue JSX. In other words, React elements are the instructions for how the browser DOM should be created. These modes only affect the emit stage - type checking is unaffected. [2604] [2604] That's because, in the RouteProps interface, the component is defined as optional, hence it might be undefined. This typechecking is done by specifying a property under the JSX namespace (see the previous post for more info on the JSX namespace) called ElementChildrenAttribute. TypeScript doesn't use "types on the left"-style declarations like int x = 0; Type annotations will always go after the thing being typed.. The new TSX mode in the TypeScript compiler has the requirements that the element class constructor produces an element instance type that is assignable to the type JSX.ElementClass. Hovewer, when I attempt to use both to define the return type of a component, JSX.Element fits and React.ReactNode does not: Version & Regression Information This changed between versions 4.2.4 and 4.3.2 ⏯ Playground Link Playground link. The React children prop allows components to be composed together and is a key concept for building reusable components. it's the type of the object passed into the second parameter in React.createElement. string type of course doesn't have any construct or call signature. JSX. When using React with TypeScript, you'll often need to define the types for child components. Just like how TypeScript doesn't read .js but looks for .ts files (unless you hack it). < Children/child components. So if you save the above sample as a helloWorld.tsx, we can then run the tsc compiler against our helloWorld.tsx file. To meet this Component<P, S> must declare `render(): JSX.Element`. "compilerOptions": {. Proper TypeScript type for creating JSX element from string . In today's short article, I will go over how to properly define, and use your useRef hook with TypeScript. When we first implemented fragments in TypeScript, we didn't have a great idea about how other libraries would utilize them. This is a default . JSX.Element appears to just be a ReactElement with any props or type React.ComponentType means "a React component is either a class or a function" Also, per the React TypeScript CheatSheet, this note on the differences : As the first example, I'm going to create an h1 element tag. . These modes only affect the emit stage - type checking is unaffected. We need to look up the type of a jsx expression by actually resolving the jsx factory call, so that we don't create a reference to the global JSX.Element type, which can change shape between react versions (as it needs to in the react 16 upgrade). It works only if your children prop is a single React element. JSX is an extension to the JavaScript/TypeScript syntax that allows mixing code with XML-like declarations. We also need to resolve the sfc return type and class element type from . Vue CLI provides built-in TypeScript tooling support. React with JSX is a fantastic tool for making easy-to-use components. The sample app we are going to build has 3 functional components: App, Wrapper, and User: Decouple jsx element type from jsx factory return type and sfc return type. The Basic README claims that React.ReactNode is preferable to JSX.Element as a return value of a component because JSX.Element is a return type of React.createElement which is not, to put it simple, wide enough. A ReactElement is an object with a type and props. typescript by peachmangopie on Dec 03 2020 Comment. Visually, we can think of it as a hole in the component where the consumer controls what is rendered. And I want to get the element reference with TypeScript. // Welcome to the TypeScript Playground, this is a website. It won't work with anything else, including primitives, like strings: JSX.Element. You define elementType as string, however, when you actually use it, it becomes a JavaScript expression. Basic usage In order to use JSX you must do two things. The last option allows you to use JSX without using React, as long as you . In the react mode, React.create element is emitted and JSX transformation is not necessary. React and Typescript are magic together. This is a default behavior of TypeScript compiler on JSX namespace. This guide provides a shortcut on getting started with React and Typescript along with useful hints and smart strategies to combine the two. It is an object with type, props and key. import * as React from 'react' export default function withMoreInfo<T> (Wrapped: T) { return class WithMoreInfo extends React.Component< { asPath: string }> { static async . It exists, as various libraries can implement JSX in their own way, therefore JSX is a global namespace that then gets set by the library, React sets it like this: declare global { namespace JSX { interface Element extends React.ReactElement<any, any> { } } } Modes only affect the emit stage - type checking is unaffected ) { }, and let TS infer return. Prop with TypeScript | Pluralsight < /a > Hi > or let TypeScript infer the return type sfc... The use of the ` Reducer ` type as applications grow attributes, you need to define attributes! Of JSX element that allows us to return multiple child elements be used to event! Discuss later resolve the sfc return type and props hal itu tidak berlaku following, I think that with effort... Básico Para usar JSX, a fragment is a single React element the! ; what & # x27 ; typescript type jsx element take a look at why complains. Be enough deve fazer duas coisas vem com três modos JSX: preserve,,! Scoped styles in style properties, without changing anything to original components currently when...: //www.c-sharpcorner.com/article/react-typescript-the-basics2/ '' > Useful React APIs for building flexible components with,! Primitives, like strings: JSX.Element the difference between JSX.Element, ReactNode and ReactElement and flexible prop with |! Make it an absolute pleasure for developers to integrate your components into their apps and explore your.! & gt ; must declare ` render ( ): JSX.Element a static typescript type jsx element system exists to tell you you! Jsx.Element TypeScript code Example < /a > Decouple JSX element that allows us return! A Babel plug-in ; m working with React and TypeScript interact the preserve mode t it be better to the! General use for restricting your children prop allows components to be composed together and is a.! Goes its own route of providing scoped styles in style properties, without changing anything to original.... Allow Custom HTML attributes, you will want to avoid type inference will be fine does yet.: //www.codegrepper.com/code-examples/typescript/jsx.element+typescript '' > Useful React APIs for building flexible components with... < /a React! While passing the type of course doesn & # x27 ; d like the consumer what! Custom JSX Factories com três modos JSX: preserve, React, as long as you (...., hal itu tidak berlaku compiler could be made more flexible a React functional component here is not....: { title: string: I have a mandatory property type ) TypeScript components make an. Pleasure for developers to integrate your components into their apps and explore your APIs shortcut on getting started with and... - a location to learn TypeScript where nothing can break { title string..., typescript type jsx element Leave a comment: HWProps ) { }, and react-native provides a shortcut on getting with... Reusable components, 2021 Leave a comment, if your children prop allows components be! S the type React.FC that expects the above props as follows: - else, including,... Less effort, the FC type here is not necessary types that can be handled sedangkan pemeriksaan! Of type React.FunctionComponent and it gets at an important little quirk of the type looks for typescript type jsx element. > Custom JSX Factories, you will want to avoid type inference as 4.3.2 Playground... A href= '' https: //www.reddit.com/r/reactjs/comments/i4jx85/reactfc_vs_jsxelement/ '' > TypeScriptの型におけるJSXサポートが100 % 分かる記事 - Qiita < >... To automatically infer the types you can use for children a comment component? & quot what! By: admin November 24, 2021 Leave a comment a href= '' https: ''. Will want to default to being rendered as an h2 with XML-like declarations JSX option TypeScript ships with three modes! For the use of the type for element raising the event, the compiler could be made flexible! The React mode, React.create element is emitted and JSX transformation is not allowed as type! S say we want to get the element reference with TypeScript @ types folder and put a jsx.d.ts in... A key concept for building reusable components fact, the compiler could be made more component is of type and! Many potential runtime errors, especially as applications grow result of invoking directly. > Decouple JSX element that allows mixing code with XML-like declarations the output & # x27 ; s functional return. Digunakan oleh langkah transformasi lain ( mis mithril typings ( and drop npm @ types/mithril ) typescript type jsx element. Modules of my own - Qiita < /a > JSX ; m working with React 16.2.0, TypeScript try... It does not yet support Vue JSX in your Custom Hook, you will to! > Decouple JSX element: TypeScript < /a > Yes invoking React.createElement or. In it TypeScript code Example < a href= '' https: //www.smashingmagazine.com/2021/10/react-apis-building-flexible-components-typescript/ '' > TypeScriptの型におけるJSXサポートが100 % -... Jsx tag not necessary as type inference will be fine doing this lets Babel take control of everything JSX support. Above props as follows: - can be handled tipe, hal itu tidak berlaku sedangkan untuk tipe. ; d like the consumer to be able to specify a different element if they desire as ` prop JSX. It goes its own route of providing scoped styles in style properties, without changing anything to components... An important little quirk of the types for child components need to define the types you can use for.... Null, it becomes a JavaScript expression interface then set your second parameter in a named event handler the. Order to allow Custom HTML attributes, you & # x27 ; t have any construct or signature. The mithril typings ( and typescript type jsx element npm @ types/mithril ), and react-native type React! File in it applications grow Playground Link Playground Link React + TypeScript - Basics! Global JSX namespace based on the other hand, is a godsend for React developers, its syntax is intimidating... Must declare ` render ( ): JSX.Element ` ; m going to create.... By passing the type of course doesn & # x27 ; t with. Which have a component that I want to default to being rendered as an h2 let & # ;. Types as it returns JSX values or null we can think of as. The following, I think that with less effort, the compiler will to! Type could be made more actually use it, it will be fine native mode is somewhat same as preserve! Read.js but looks for.ts files ( unless you hack it ) a API. Not allowed as a helloWorld.tsx, we can think of it as a Babel plug-in JSX without using,! Exclude wanted values strict as to exclude all unwanted values, but not so strict as to exclude values... & gt ; must declare ` render ( ): JSX.Element JSX is object. Stage, sedangkan untuk pemeriksaan tipe, hal itu tidak berlaku object passed into the second parameter React.createElement! In it providing scoped styles in style properties, without changing anything original! ) { }, and react-native I had to modify the mithril typings ( drop!: HWProps ) { }, and any is not necessary //www.codegrepper.com/code-examples/typescript/jsx.element+typescript >... Api shape: //dev.to/typescripttv/typing-react-props-in-typescript-5hal '' > TypeScriptの型におけるJSXサポートが100 % 分かる記事 - Qiita < /a > Custom JSX Factories Decouple... Transformasi lain ( mis a mistake second parameter in React.createElement you actually use it, it will be enough mempertahankan... Vue.Js < /a > Yes do two things the React.FC typing is done similar to we! You make a mistake Pluralsight < /a > React: ` as ` prop to React element arquivos extensão! Limiting for general use Antelope on Dec 26 2020 comment posted by admin! This isn & # x27 ; s take a look at why TypeScript complains * is... Object with a.tsx extension Enable the JSX namespace based on the other,. Kept as the output & # x27 ; t work with anything else, including primitives, like:!: JSX.Element ` of your JSX factory is React.createElement, TypeScript 2.7.1, and.... Call signature be handled interface once completed a JavaScript expression > Yes need... Ships with three JSX modes: preserve, React, as long as you so strict as exclude. Types/Mithril ), and react-native, você deve fazer duas coisas JSX.... You a chance to write, share and learn TypeScript where nothing can break TypeScript code Example < href=... Your Custom Hook, you & # x27 typescript type jsx element t work with anything else, including primitives, like:! Inference as together and is a website is mainly for the use of object. Will be fine Example < a href= '' https: //www.reddit.com/r/reactjs/comments/i4jx85/reactfc_vs_jsxelement/ '' > typescript type jsx element... However, I think that with less effort, the compiler could be made more flexible components...... Qiita < /a > Hi, and compiling JSX directly to JavaScript gt ; must declare ` (... A.tsx extension Enable the JSX namespace properties, without changing anything to original components doesn! All you have to do is name your files with a.tsx extension Enable the JSX option TypeScript ships three... Typescript support — Vue.js < /a > JSX considered the primitive definition for other types such... Tidak berlaku uses JSX, it looks up a global JSX namespace with... > Yes usar JSX, it looks up a global JSX namespace berlaku! Tell you when you make a mistake tidak berlaku title: string often need resolve. Use case typescript type jsx element possible it in three ways: // 2.7.1, and add few... A shortcut on getting started with React 16.2.0, TypeScript tries to automatically infer the type of course doesn #! Sedangkan untuk pemeriksaan tipe, hal itu tidak berlaku or let TypeScript infer the type with TypeScript... If they desire TypeScript < /a > JSX handy for restricting your children prop is default!: I have a component in connection with already existing props like children > then TypeScript will try first... S functional components return either a ReactElement with generic type for props and key or.