"use strict"; const {Fragment: _Fragment, jsx: _jsx, jsxs: _jsxs} = arguments[0]; const {useMDXComponents: _provideComponents} = arguments[0]; function _createMdxContent(props) { const _components = { code: "code", p: "p", pre: "pre", span: "span", ..._provideComponents(), ...props.components }; return _jsxs(_Fragment, { children: [_jsx(_components.p, { children: "React is fast by default. So the useTransition hook has specific use cases and is probably not something you will use in all your applications. useTransition hook is a hook available in React 18 and above and is used to manage asynchronous operations. This hook is designed to provide better performance and faster user experience, especially in large and complex applications. Thus, the user interface does not freeze and user interaction is not hindered." }), "\n", _jsx(_components.p, { children: "In the example below, when you click the button, 50 000 items are added to the \"items\" array and these items are displayed as \"div\" elements containing the \"☠️\" symbol." }), "\n", _jsx(_components.pre, { className: "language-javascript", children: _jsxs(_components.code, { className: "language-javascript", children: [_jsx(_components.span, { className: "token keyword module", children: "import" }), " ", _jsxs(_components.span, { className: "token imports", children: [_jsx(_components.span, { className: "token maybe-class-name", children: "React" }), _jsx(_components.span, { className: "token punctuation", children: "," }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), " useState ", _jsx(_components.span, { className: "token punctuation", children: "}" })] }), " ", _jsx(_components.span, { className: "token keyword module", children: "from" }), " ", _jsx(_components.span, { className: "token string", children: "\"react\"" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n\n", _jsx(_components.span, { className: "token keyword", children: "function" }), " ", _jsx(_components.span, { className: "token function", children: _jsx(_components.span, { className: "token maybe-class-name", children: "App" }) }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "\n ", _jsx(_components.span, { className: "token keyword", children: "const" }), " ", _jsx(_components.span, { className: "token punctuation", children: "[" }), "items", _jsx(_components.span, { className: "token punctuation", children: "," }), " setItems", _jsx(_components.span, { className: "token punctuation", children: "]" }), " ", _jsx(_components.span, { className: "token operator", children: "=" }), " ", _jsx(_components.span, { className: "token function", children: "useState" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token punctuation", children: "[" }), _jsx(_components.span, { className: "token punctuation", children: "]" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n ", _jsx(_components.span, { className: "token keyword", children: "const" }), " ", _jsx(_components.span, { className: "token function-variable function", children: "addItem" }), " ", _jsx(_components.span, { className: "token operator", children: "=" }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token arrow operator", children: "=>" }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "\n ", _jsx(_components.span, { className: "token keyword", children: "const" }), " newItems ", _jsx(_components.span, { className: "token operator", children: "=" }), " ", _jsx(_components.span, { className: "token known-class-name class-name", children: "Array" }), _jsx(_components.span, { className: "token punctuation", children: "." }), _jsx(_components.span, { className: "token keyword module", children: "from" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token punctuation", children: "{" }), " ", _jsx(_components.span, { className: "token literal-property property", children: "length" }), _jsx(_components.span, { className: "token operator", children: ":" }), " ", _jsx(_components.span, { className: "token number", children: "50000" }), " ", _jsx(_components.span, { className: "token punctuation", children: "}" }), _jsx(_components.span, { className: "token punctuation", children: "," }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsxs(_components.span, { className: "token parameter", children: ["_", _jsx(_components.span, { className: "token punctuation", children: "," }), " index"] }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token arrow operator", children: "=>" }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "\n ", _jsx(_components.span, { className: "token keyword control-flow", children: "return" }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), "\n ", _jsx(_components.span, { className: "token operator", children: "<" }), "div key", _jsx(_components.span, { className: "token operator", children: "=" }), _jsx(_components.span, { className: "token punctuation", children: "{" }), "index", _jsx(_components.span, { className: "token punctuation", children: "}" }), _jsx(_components.span, { className: "token operator", children: ">" }), "\n ", _jsx(_components.span, { className: "token operator", children: "<" }), "p", _jsx(_components.span, { className: "token operator", children: ">" }), "☠️", _jsx(_components.span, { className: "token operator", children: "<" }), _jsx(_components.span, { className: "token operator", children: "/" }), "p", _jsx(_components.span, { className: "token operator", children: ">" }), "\n ", _jsx(_components.span, { className: "token operator", children: "<" }), _jsx(_components.span, { className: "token operator", children: "/" }), "div", _jsx(_components.span, { className: "token operator", children: ">" }), "\n ", _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n ", _jsx(_components.span, { className: "token punctuation", children: "}" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n ", _jsx(_components.span, { className: "token function", children: "setItems" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "newItems", _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n ", _jsx(_components.span, { className: "token punctuation", children: "}" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n\n ", _jsx(_components.span, { className: "token keyword control-flow", children: "return" }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), "\n ", _jsx(_components.span, { className: "token operator", children: "<" }), "div", _jsx(_components.span, { className: "token operator", children: ">" }), "\n ", _jsx(_components.span, { className: "token operator", children: "<" }), "button onClick", _jsx(_components.span, { className: "token operator", children: "=" }), _jsx(_components.span, { className: "token punctuation", children: "{" }), "addItem", _jsx(_components.span, { className: "token punctuation", children: "}" }), _jsx(_components.span, { className: "token operator", children: ">" }), _jsx(_components.span, { className: "token maybe-class-name", children: "Add" }), " ", _jsx(_components.span, { className: "token maybe-class-name", children: "Item" }), _jsx(_components.span, { className: "token operator", children: "<" }), _jsx(_components.span, { className: "token operator", children: "/" }), "button", _jsx(_components.span, { className: "token operator", children: ">" }), "\n ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "items", _jsx(_components.span, { className: "token punctuation", children: "}" }), "\n ", _jsx(_components.span, { className: "token operator", children: "<" }), _jsx(_components.span, { className: "token operator", children: "/" }), "div", _jsx(_components.span, { className: "token operator", children: ">" }), "\n ", _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n", _jsx(_components.span, { className: "token punctuation", children: "}" }), "\n\n", _jsx(_components.span, { className: "token keyword module", children: "export" }), " ", _jsx(_components.span, { className: "token keyword module", children: "default" }), " ", _jsx(_components.span, { className: "token maybe-class-name", children: "App" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }) }), "\n", _jsx(_components.p, { children: "It will run very slowly. It will take a long time for them to appear on the screen." }), "\n", _jsx(_components.p, { children: "Now let's do our example with the useTransition hook" }), "\n", _jsx(_components.pre, { className: "language-javascript", children: _jsxs(_components.code, { className: "language-javascript", children: [_jsx(_components.span, { className: "token keyword module", children: "import" }), " ", _jsxs(_components.span, { className: "token imports", children: [_jsx(_components.span, { className: "token maybe-class-name", children: "React" }), _jsx(_components.span, { className: "token punctuation", children: "," }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), " useState", _jsx(_components.span, { className: "token punctuation", children: "," }), " useTransition ", _jsx(_components.span, { className: "token punctuation", children: "}" })] }), " ", _jsx(_components.span, { className: "token keyword module", children: "from" }), " ", _jsx(_components.span, { className: "token string", children: "\"react\"" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n\n", _jsx(_components.span, { className: "token keyword", children: "function" }), " ", _jsx(_components.span, { className: "token function", children: _jsx(_components.span, { className: "token maybe-class-name", children: "App" }) }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "\n ", _jsx(_components.span, { className: "token keyword", children: "const" }), " ", _jsx(_components.span, { className: "token punctuation", children: "[" }), "items", _jsx(_components.span, { className: "token punctuation", children: "," }), " setItems", _jsx(_components.span, { className: "token punctuation", children: "]" }), " ", _jsx(_components.span, { className: "token operator", children: "=" }), " ", _jsx(_components.span, { className: "token function", children: "useState" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token punctuation", children: "[" }), _jsx(_components.span, { className: "token punctuation", children: "]" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n ", _jsx(_components.span, { className: "token keyword", children: "const" }), " ", _jsx(_components.span, { className: "token punctuation", children: "[" }), "isAdding", _jsx(_components.span, { className: "token punctuation", children: "," }), " startAdding", _jsx(_components.span, { className: "token punctuation", children: "]" }), " ", _jsx(_components.span, { className: "token operator", children: "=" }), " ", _jsx(_components.span, { className: "token function", children: "useTransition" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n\n ", _jsx(_components.span, { className: "token keyword", children: "const" }), " ", _jsx(_components.span, { className: "token function-variable function", children: "addItem" }), " ", _jsx(_components.span, { className: "token operator", children: "=" }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token arrow operator", children: "=>" }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "\n ", _jsx(_components.span, { className: "token function", children: "startAdding" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token arrow operator", children: "=>" }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "\n ", _jsx(_components.span, { className: "token keyword", children: "const" }), " newItems ", _jsx(_components.span, { className: "token operator", children: "=" }), " ", _jsx(_components.span, { className: "token known-class-name class-name", children: "Array" }), _jsx(_components.span, { className: "token punctuation", children: "." }), _jsx(_components.span, { className: "token keyword module", children: "from" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token punctuation", children: "{" }), " ", _jsx(_components.span, { className: "token literal-property property", children: "length" }), _jsx(_components.span, { className: "token operator", children: ":" }), " ", _jsx(_components.span, { className: "token number", children: "50000" }), " ", _jsx(_components.span, { className: "token punctuation", children: "}" }), _jsx(_components.span, { className: "token punctuation", children: "," }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsxs(_components.span, { className: "token parameter", children: ["_", _jsx(_components.span, { className: "token punctuation", children: "," }), " index"] }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token arrow operator", children: "=>" }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "\n ", _jsx(_components.span, { className: "token keyword control-flow", children: "return" }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), "\n ", _jsx(_components.span, { className: "token operator", children: "<" }), "div key", _jsx(_components.span, { className: "token operator", children: "=" }), _jsx(_components.span, { className: "token punctuation", children: "{" }), "index", _jsx(_components.span, { className: "token punctuation", children: "}" }), _jsx(_components.span, { className: "token operator", children: ">" }), "\n ", _jsx(_components.span, { className: "token operator", children: "<" }), "p", _jsx(_components.span, { className: "token operator", children: ">" }), "☠️", _jsx(_components.span, { className: "token operator", children: "<" }), _jsx(_components.span, { className: "token operator", children: "/" }), "p", _jsx(_components.span, { className: "token operator", children: ">" }), "\n ", _jsx(_components.span, { className: "token operator", children: "<" }), _jsx(_components.span, { className: "token operator", children: "/" }), "div", _jsx(_components.span, { className: "token operator", children: ">" }), "\n ", _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n ", _jsx(_components.span, { className: "token punctuation", children: "}" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n\n ", _jsx(_components.span, { className: "token function", children: "setItems" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "newItems", _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n ", _jsx(_components.span, { className: "token punctuation", children: "}" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n ", _jsx(_components.span, { className: "token punctuation", children: "}" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n\n ", _jsx(_components.span, { className: "token keyword control-flow", children: "return" }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), "\n ", _jsx(_components.span, { className: "token operator", children: "<" }), "div", _jsx(_components.span, { className: "token operator", children: ">" }), "\n ", _jsx(_components.span, { className: "token operator", children: "<" }), "button onClick", _jsx(_components.span, { className: "token operator", children: "=" }), _jsx(_components.span, { className: "token punctuation", children: "{" }), "addItem", _jsx(_components.span, { className: "token punctuation", children: "}" }), _jsx(_components.span, { className: "token operator", children: ">" }), _jsx(_components.span, { className: "token maybe-class-name", children: "Add" }), " ", _jsx(_components.span, { className: "token maybe-class-name", children: "Item" }), _jsx(_components.span, { className: "token operator", children: "<" }), _jsx(_components.span, { className: "token operator", children: "/" }), "button", _jsx(_components.span, { className: "token operator", children: ">" }), "\n ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "isAdding ", _jsx(_components.span, { className: "token operator", children: "?" }), " ", _jsx(_components.span, { className: "token operator", children: "<" }), "p", _jsx(_components.span, { className: "token operator", children: ">" }), _jsx(_components.span, { className: "token maybe-class-name", children: "Adding" }), " items", _jsx(_components.span, { className: "token spread operator", children: "..." }), _jsx(_components.span, { className: "token operator", children: "<" }), _jsx(_components.span, { className: "token operator", children: "/" }), "p", _jsx(_components.span, { className: "token operator", children: ">" }), " ", _jsx(_components.span, { className: "token operator", children: ":" }), " items", _jsx(_components.span, { className: "token punctuation", children: "}" }), "\n ", _jsx(_components.span, { className: "token operator", children: "<" }), _jsx(_components.span, { className: "token operator", children: "/" }), "div", _jsx(_components.span, { className: "token operator", children: ">" }), "\n ", _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n", _jsx(_components.span, { className: "token punctuation", children: "}" }), "\n\n", _jsx(_components.span, { className: "token keyword module", children: "export" }), " ", _jsx(_components.span, { className: "token keyword module", children: "default" }), " ", _jsx(_components.span, { className: "token maybe-class-name", children: "App" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }) }), "\n", _jsx(_components.p, { children: "In this example, we saw how React can handle large batch updates without blocking the main thread. Migration helps React prioritize rebuild updates, making it more responsive to user interactions." }), "\n", _jsx(_components.p, { children: "The purpose of this code is to showcase how concurrent mode can be used to handle large batch updates to the UI without blocking the main thread, making the application more responsive to user interactions. The transition helps avoid UI jank by allowing React to prioritize rendering updates." }), "\n", _jsx(_components.p, { children: "we use the useTransition hook to manage the addition of items to the \"items\" array. When you initiate the addition, a transition sequence is used to add items to the array. The variable \"isAdding\" is used to control whether the transition is ongoing. If the addition is in progress, you'll see the \"Adding items...\" message; otherwise, the added items are rendered." }), "\n", _jsx(_components.p, { children: "This provides a better user experience for situations that involve larger operations and UI updates." })] }); } function MDXContent(props = {}) { const {wrapper: MDXLayout} = { ..._provideComponents(), ...props.components }; return MDXLayout ? _jsx(MDXLayout, { ...props, children: _jsx(_createMdxContent, { ...props }) }) : _createMdxContent(props); } return { default: MDXContent };