vue async component

Having vue wait on components which have been marked as async not only causes issues for the users, the pattern of using async/await to start data look up is present everywhere. Officiellement du moins. How hard is this for async loading of router level components? Before we start by lazy loading a component, let's first remember how we usually load a component. In Vue 2.3.0 or later, we can define an async component by creating a function that returns an object that has the promise that resolves to the component as the component that’s rendered. Nope, if you need to do something asynchronous, then you can't use a computed property. Check out more details on in the API reference. Vue.component(name, definition). En effet, chaque fois que vous basculez vers un nouvel onglet, Vue crée une nouvelle instance du composantOngletActuel. But just to refresh: async components are useful when you have a large(ish) component that is either a) not needed right away in your app, or b) may never be needed in a given session. // La fonction `import` dynamique retourne une `Promise`. Vue déclenchera la fonction usine seulement lorsque le rendu du composant est nécessaire, et mettra en cache le résultat pour les futurs nouveaux rendus. js; vuejs; async; axios; Most Vue apps need asynchronous HTTP requests, and there are many ways to realize … We’ll use this to style the app: for async stuff. Par défaut : 200ms. Installation. In some cases it might be good, and if a feature would be … It's an executor for a Promise, i.e. Pour rendre cela plus facile, Vue vous permet de définir un composant en tant que fonction usine qui va résoudre de façon asynchrone la définition de votre composant. Précédemment, nous avons utilisé l’attribut is pour basculer entre des composants dans une interface avec des onglets : Toutefois, lors de la bascule d’un composant à l’autre, vous voudrez parfois maintenir leur état ou éviter de refaire leur rendu pour des raisons de performance. Pour async composants Vue.js le résoudre argument est la fonction qui est appelée en cas de succès de l'appel asynchrone, de sorte que votre besoin() l'appel doit être à l'intérieur de l'appelé résoudre fonction. // Le délai à patienter avant d'afficher le composant de chargement. Le setTimeout est là en guise de démonstration ; à vous de décider comment vous souhaitez récupérer le composant. Vue.component('async-webpack-example', function (resolve) {// This special require syntax will instruct Webpack to // automatically split your built code into bundles which // are loaded over Ajax requests. A flexible modal component for Vue with the ability of asynchronous lazy loading. , // Passe la définition du composant à la fonction de rappel `resolve`, // Cette syntaxe spéciale `require` indique à webpack de, // diviser automatiquement votre code en sortie en paquets. It would force explicitly converting the code in these lifecycle hooks to unawaited promises to explicitly avoid blocking vue. // qui seront chargés via des requêtes AJAX. Transitions d'entrée, de sortie et de liste, Regarder le cours gratuit sur Vue School (EN), fonctionnalité de découpage de code de webpack. Earlier, we used the is attribute to switch between components in a tabbed interface: When switching between these components though, you'll sometimes want to maintain their state or avoid re-rendering for performance reasons. Vue.component( 'async-webpack-example', // The `import` function below returns a Promise. It would force explicitly converting the code in these lifecycle hooks to unawaited promises to explicitly avoid blocking vue. You can also return a Promise in the factory function, so with Webpack 2 or later and ES2015 syntax you can do: You can also use defineAsyncComponent when registering a component locally: Async components are suspensible by default. §Interactive demo. With some experience it becomes natural to handle computed properties as purely synchronous functions. This is a mini Vue.js app with its own router and mount point inside a Markdown component. Pour résoudre ce problème, nous pouvons envelopper notre composant dynamique dans un élément : Désormais, l’onglet Posts conserve son état (le post sélectionné) même lorsqu’il n’est pas dessiné. Assuming you're bundling your code with Webpack or something similar, the easiest way to do this is to use the dynamic … Transcript. But to start: what is lazy loading? The vue-async-computed package allows you to create and consume asynchronous computed properties in your components by binding the resolved value of a promise to a component property. It’s a new way of managing state in your React components without the traditional class syntax. So, computed properties are "yay!" Promise's resolve callback should be called when you have retrieved your component definition from the server. by Vue (@Vue) Code. In this article, I’ll demonstrate how to optimize performance of Vue app with async components. You can also call reject(reason) to indicate the load has failed. If you try to do something async, then you'll end up returning a Promise instead of the real value. Using a Vue Renderless Component to handle async requests to abstract the HTTP request logic and make it reusable. Dynamic imports are async. it has a res… With the tweak, we are declaring the canvas editor as a async vue component. If you need an async computed property, then you probably made an architectural mistake in your component. In this case, the loading state will be controlled by the , and the component's own loading, error, delay and timeout options will be ignored. Now that we have a handle on asynchronous components, let’s truly harvest their power by only loading them when they’re really needed. While a simple request is straightforward with axios, we usually want to cover at least two additional states: Rather than having a definition object as the second argument, async components have a function. by Vue (@Vue) Vue apps created with Vue CLI has built-in support for dynamic imports, which is what we need to create an async component. Let’s proceed to build a basic book donation app to show how async components can be leveraged. You'll notice that if you select a post, switch to the Archive tab, then switch back to Posts, it's no longer showing the post you selected. Consultez ce fiddle pour le code complet. Another thing that is very easy to do in Vue.js is rendering components dynamically. Most Vue apps need asynchronous HTTP requests, and there are many ways to realize them: in the mounted() lifecycle hook, in a method triggered by a button, within the store (when using vuex) or in the asyncData() and fetch() methods (with Nuxt)..
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