[英]How to react to a global variable with Vue?
I have a mobile webview that is injected with some global config object: 我有一个移动Web视图,其中注入了一些全局配置对象:
Vue.prototype.$configServer = {
MODE: "DEBUG",
isMobile: false,
injected: false,
version: -1,
title:"App",
user: null,
host: "http://127.0.0.1:8080"
}
Later the WebView inject this: 后来,WebView将其注入:
Vue.prototype.$configServer = {
MODE: "DEBUG",
title: "App",
version: "2.0",
isMobile: true,
injected: true,
host: "http://127.0.0.1:8081"
}
And try to use it for the component: 并尝试将其用于组件:
const HomePage = {
key: 'HomePage',
template: '#HomePage',
components: { toolbar },
data() {
return {
items: [
{name:"Login", link:"login"},
]
}
},
computed:{
config() {
return Vue.prototype.$configServer
}
},
};
However the page is not updated. 但是,该页面未更新。 How react to the change? 如何应对变化?
PD: I confirm the object is updated with the safari debug tools. PD:我确认使用Safari调试工具更新了对象。 Also test in a local html. 还要在本地html中测试。
Instead of putting the config into the prototype of Vue, you can actually add it as a data option inside the main vue instance which will guarantee you that all your config properties will be reactive. 您实际上可以将配置作为数据选项添加到主vue实例中,而不必保证将配置放入Vue的原型中,这将确保您所有的配置属性都是反应性的。 As mentioned in the docs 如文档中所述
When you pass a plain JavaScript object to a Vue instance as its data option, Vue will walk through all of its properties and convert them to getter/setters using Object.defineProperty. 当您将纯JavaScript对象作为数据选项传递给Vue实例时,Vue将遍历其所有属性,并使用Object.defineProperty将它们转换为getter / setter。
Having said that whenever you update your config properties, vue will react to it. 话虽如此,只要您更新配置属性,vue都会对此做出反应。
Now let's see how to do it in code: 现在让我们看看如何在代码中做到这一点:
new Vue(){
data:{ //only place where data is not a function
configServer = {
MODE: "DEBUG",
isMobile: false,
injected: false,
version: -1,
title:"App",
user: null,
host: "http://127.0.0.1:8080"
}
}
}
Now whenever you need to access your config you can directly access it from any component using $root. 现在,每当需要访问配置时,都可以使用$ root从任何组件直接访问它。 Like this.$root.configServer
. 像this.$root.configServer
。
Well that's it. 就是这样。
I hope it helps. 希望对您有所帮助。
There are 3 ways to acheive what you want 有3种方法来实现您想要的
1- Make sure you import vue in your component 1-确保在组件中导入vue
import 'Vue' from vue
...
...
...
computed:{
config() {
return Vue.prototype.$configServer
}
2- If you don't want to import vue the you can directly access prototype using proto from any instance. 2-如果您不想导入vue,则可以从任何实例使用proto直接访问原型。
computed:{
config() {
return this.__proto__.$configServer
}
3- As you have added the config in the prototype you can actually access is directly from the vue instance using this
3-在原型中添加配置后,您实际上可以直接使用this
实例从vue实例访问
computed:{
config() {
return this.$configServer
}
},
Well whatever style matches yours you can choose that. 好吧,无论哪种样式适合您,您都可以选择。
But I would personally recommend using the 3rd one, because accessing the prototype of instance is sort of an anti-pattern. 但是我个人建议使用第3个,因为访问实例的原型有点像反模式。
I hope it helps. 希望对您有所帮助。
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