The component instance proxies access to the properties on its data object. Let's have a look at the bigger picture first and then dig deeper. Read that first if you are new to components. We'll use this structure: ./images/cameras/${cameraName}.jpg. So far, you've seen props passed a static value, like in: You've also seen props assigned dynamically with v-bind or its shortcut, the : character, such as in: In the two examples above, we happen to pass string values, but any type of value can actually be passed to a prop. In case anyone finds this issue from google searching for the same thing in Vue 2.0 and figures out that interpolation in props has been removed like I did, here is the proper way to do this is to simply do or . However, one huge change in Vue3 is the introduction of the setup method . This page assumes you've already read the Components Basics. You cannot pass data from a child to a parent. There are two specific things to keep in mind when dealing with props: Props are passed down the component tree to descendents (not up) Props are read-only and cannot be modified (as you may have discovered) Vue uses one way data flow, meaning that data can only flow from a parent into a child component. # Boolean mode When props is set to true, the route.params will be set as the component props. It builds on the popularity and ease of use of Vue 2. The type can be one of the following native constructors: In addition, type can also be a custom constructor function and the assertion will be made with an instanceof check. This means you should avoid destructuring them and always reference properties as attrs.x or slots.x.Also note that unlike props, attrs and slots are not reactive. In this case (Array/Object props) it's similar to why data is a function in Vue: we have an explicit factory method that can be easily extended (or even replaced with a factory/singleton function completely external to a component or a regular utility function if you wish! This feature idea comes from the use of it in react, which is documented here. Some of them are necessary for the component to work correctly. In this case (Array/Object props) it's similar to why data is a function in Vue: we have an explicit factory method that can be easily extended (or even replaced with a factory/singleton function completely external to a component or a regular utility function if you wish! 更新时间:2020年07月30日 09:50:16 作者:zhaobao1830 . When props is an object, this will be set as the component props as-is. We can specify which props are required and which ones aren't in our prop definition: Here we set our name prop to be required by adding required: true to its prop definition. One-time Donations … In our templates we saw that we just needed the prop name, like this: {{ rating }}. props do update reactively. This is similar to how in Javascript we can pass variables into functions as arguments: Here we pass the variable myMessage into the function as the argument message. There are two specific things to keep in mind when dealing with props: 1. The main reason this gives better type inference is that it is easier to type props and context, which are easily defined objects, to this, which is highly dynamic in JavaScript. Others are just extras, giving additional functionality if you need it. Vue will recursively convert its properties into getter/setters to make it “reactive”. Props are read-only and cannot be modified (as you may have discovered) Vue uses one way data flow, meaning that data can only flow from a parent into a child component. Prop Validation But there are a couple rules you need to know about first. Guide Style Guide Cookbook Examples Contribute Migration from Vue 2 API Reference Ecosystem. And because that parent component "owns" that value it passed down, the child can't modify it. Default Prop Values. There are 3 specific things here I'd like to cover: 1. Get discount. By now you should know everything you need to know about props in order to be a highly productive Vue developer. Once that is done, Vue pretty much works as advertised. They can be: By adding in prop types like this we can set expectations for what we'll receive. The : tells Vue that the object isn’t a string. For example, we could use a logical OR to use a default if we don't have an image for the camera: More commonly, we use the shorthand for v-bind which is just : and reduces clutter in the code: Because you can put in any arbitrary piece of Javascript, you can do a lot of nifty little things, such as dynamically adding a class name, or implementing a hover. Useful for when the props are static. I’ve heard when Vetur, the VSCode plugin for Vue components is updated for Vue 3, you will actually get type inference in