Inferno is an insanely fast, React-like library for building high-performance user interfaces on both the client and server.
The main objective of the InfernoJS project is to provide the fastest possible runtime performance for web applications. Inferno excels at rendering real time data views or large DOM trees.
The performance is achieved through multiple optimizations, for example:
createVNode calls, instead of createElement calls.
Optimizing runtime performance of the application. linkEvent feature removes the need to use arrow functions or binding event callbacksinferno-servercreatePortal - APIor using object literal syntax
. For camelCase syntax support see [inferno-compat`](https://github.com/infernojs/inferno/tree/master/packages/inferno-compat).
- Fragments (v6)
- createRef and forwardRef APIs (v6)
- componentDidAppear, componentWillDisappear and componentWillMove (v8) - class and function component callbacks to ease animation work, see inferno-animation package
Inferno v9 requires following features to be present in the executing runtime:
PromiseString.prototype.includes()String.prototype.startsWith()Array.prototype.includes()Object.spread()for ... ofSince version 4 we have started running our test suite without any polyfills. Inferno is now part of Saucelabs open source program and we use their service for executing the tests.
InfernoJS is actively tested with browsers listed below, however it may run well on older browsers as well. This is due to limited support of browser versions in recent testing frameworks. https://github.com/jasmine/jasmine/blob/main/release_notes/5.0.0.md
Live examples at https://infernojs.github.io/inferno
Let's start with some code. As you can see, Inferno intentionally keeps the same design ideas as React regarding components: one-way data flow and separation of concerns.
In these examples, JSX is used via the Inferno JSX Babel Plugin to provide a simple way to express Inferno virtual DOM. You do not need to use JSX, it's completely optional, you can use hyperscript or createElement (like React does). Keep in mind that compile time optimizations are available only for JSX.
import { render } from 'inferno';
const message = "Hello world";
render(
<MyComponent message={ message } />,
document.getElementById("app")
);
Furthermore, Inferno also uses ES6 components like React:
import { render, Component } from 'inferno';
class MyComponent extends Component {
constructor(props) {
super(props);
this.state = {
counter: 0
};
}
render() {
return (
<h1>Header!</h1>
<span>Counter is at: { this.state.counter }</span>
);
}
}
render(
<MyComponent />,
document.getElementById("app")
);
Because performance is an important aspect of this library, we want to show you how to optimize your application even further.
In the example below we optimize diffing process by using JSX $HasVNodeChildren and $HasTextChildren to predefine children shape compile time.
In the MyComponent render method there is a div that contains JSX expression node as its content. Due to dynamic nature of Javascript
that variable node could be anything and Inferno needs to go through the normalization process to make sure there are no nested arrays or other invalid data.
Inferno offers a feature called ChildFlags for application developers to pre-define the shape of vNode's child node. In this example case
it is using $HasVNodeChildren to tell the JSX compiler, that this vNode contains only single element or component vNode.
Now inferno will not go into the normalization process runtime, but trusts the developer decision about the shape of the object and correctness of data.
If this contract is not kept and node variable contains invalid value for the pre-defined shape (fe. null), then application would crash runtime.
There is also span-element in the same render method, which content is set dynamically through _getText() method. There $HasTextChildren child-flag
fits nicely, because the content of that given "span" is never anything else than text.
All the available child flags are documented here.
import { createTextVNode, render, Component } from 'inferno';
class MyComponent extends Component {
constructor(props) {
super(props);
this.state = {
counter: 0
};
}
_getText() {
return 'Hello!';
}
render() {
const node = this.state.counter > 0 ?
0
: <span $HasTextChildren>{this._getText()}</span>;
return (
<h1>Header!</h1>
{node}
);
}
}
render(
<MyComponent />,
document.getElementById("app")
);
To tear down inferno application you need to render null on root element.
Rendering null will trigger unmount lifecycle hooks for whole vDOM tree and remove global event listeners.
It is important to unmount unused vNode trees to free browser memory.
import { createTextVNode, render, Component } from 'inferno';
const rootElement = document.getElementById("app");
// Start the application
render(
<ExampleComponent/>,
rootElement
);
// Tear down
render(
null,
rootElement
);
If you have built something using Inferno you can add them here:
The easiest way to get started with Inferno is by using Create Inferno App.
Alternatively, you can try any of the following: * the Inferno Boilerplate for a very simple setup. * for a more advanced example demonstrating how Inferno might be used, we recommend trying out Inferno Starter Project by nightwolfz. * for using Inferno to build a mobile app, try Inferno Mobile Starter Project by Rudy-Zidan. * for TypeScript support and bundling, check out ts-plugin-inferno, or inferno-typescript-example. * for an example of how to use Inferno in codesandbox: https://codesandbox.io/s/znmyj24w4p * for using parcel and typescript
Core package:
npm install --save inferno
Addons:
# server-side rendering
npm install --save inferno-server
# routing
npm install --save inferno-router
Pre-bundled files for browser consumption can be found on our cdnjs:
Or on jsDelivr:
https://cdn.jsdelivr.net/npm/inferno@latest/dist/inferno.min.js
Or on unpkg.com:
https://unpkg.com/inferno@latest/dist/inferno.min.js
npm install --save-dev babel-plugin-inferno
npm install --save inferno-hyperscript
npm install --save inferno-create-element
npm install --save-dev inferno-compat
Note: Make sure you read more about inferno-compat before using it.
Inferno now has bindings available for some of the major state management libraries out there:
inferno-reduxinferno-mobx@cerebral/infernoInferno has its own JSX Babel plugin.
onClick).createRef or callback ref API$ claude mcp add inferno \
-- python -m otcore.mcp_server <graph>