Render Functions & JSX

This page contains a detailed API reference for the React component class definition. It assumes you’re familiar with fundamental React concepts, such as Components and Props, as well as State and Lifecycle. If you need to render more than one HTML element, then you have to keep them within a parent element. If you’re currently using this.refs.textInput to access refs, we recommend using either the callback pattern or the createRef API instead. If you use React 16.2 or lower, or if you need more flexibility than provided by ref forwarding, you can use this alternative approach and explicitly pass a ref as a differently named prop. Your first inclination may be to use refs to “make things happen” in your app.

Where can render methods be used

However, it’s better to use other approaches like switch statements for more complex logic. To find the current layout, Rails first looks for a file in app/views/layouts with the same base name as the controller. For example, rendering actions from the PhotosController class will use app/views/layouts/photos.html.erb (or app/views/layouts/photos.builder). If there is no such controller-specific layout, Rails will use app/views/layouts/application.html.erb or app/views/layouts/application.builder.

Conditional Rendering With React Router

Now, every time we want the mouse position for a different use case, we have to create a new component (i.e. essentially another ) that renders something specifically for that use case. The term “render prop” refers to a technique for sharing code between React components using a prop whose value is a function. H() is short for hyperscript – which means “JavaScript that produces HTML (hypertext markup language)”. This name is inherited from conventions shared by many virtual DOM implementations.

In most cases, you can attach a ref to the DOM node and avoid using findDOMNode at all. React expects that the rendered content is identical between the server and the client. It can patch up differences in text content, but you should treat mismatches as bugs and fix them. In development mode, React warns about mismatches during hydration.

Example of Using Render in React JS

Ref updates happen before componentDidMount or componentDidUpdate lifecycle methods. In React, Render is the technique that can redirect a page with the help of function render(). Most importantly, render a function we can use to define the HTML code within the HTML element. It helps to display certain views what is a rendering in the UI using certain logic defined in the render function and returns the output. The logical && operator is a concise method for rendering components or elements based on a condition. Returning null from a component’s render method does not affect the firing of the component’s lifecycle methods.

The function is called the first time a user sees an application and every time there’s a change to state and props. Sometimes a small change in a component’s state triggers the re-render of all its children components in the component tree. This might seem inefficient, but React elements returned by the render() function are just plain JavaScript objects. If you’re able to use SSG for your website, then there are some great benefits to gain. Most notably, the performance of SSG sites is the best out of all three rendering methods. This is due to having the rendering complete before the user requests a page.