I am trying to use vue-native-websocket and the wss is dynamic because it needs an access token.
So I have this:
import VueNativeSock from 'vue-native-websocket';
Vue.use(VueNativeSock, this.monitor);
export default {
created() {
this.$options.sockets.onmessage = this.handleToggle;
},
data() {
return {
type: false
};
},
methods: {
handleToggle(data) {
const object = JSON.parse(data.data);
console.log(object);
this.status = object.data;
}
},
props: ['items', 'monitor']
};
As you can see, the prop monitor is passed but when it comes time to do Vue.use()... I get undefined. How do I pass a dynamic variable to a Vue use?
Vue.use is for registering plugins globally.
I didn't use vue-native-websocket before. But
import VueNativeSock from 'vue-native-websocket';
Vue.use(VueNativeSock, ....);
should be done in the place where Vue is initiated (where new Vue({...}) is, it's in main.js in a typical vue-cli generated project.) . Not inside component.
Vue.use should also be executed before new Vue({...}) in main.js.
Therefore, I don't think you would be able to make wss dynamic, unless this plugin has a specified method for you do to that.
Related
I declare a global variable in the main.js of the Vue.js project.
Vue.prototype.$API = "myapihere"
And I want to use this from everywhere.
and it's work properly by using this.$API.
But in Vuex it does not work.
console.log(this.$API);
Here this.$API is undefined.
How I use my $API in Vuex.
Vue 2 and Vuex 3 answer
In the store you can access the vue instance by accessing this._vm
const store = new Vuex.Store({
mutations: {
test(state) {
console.log(this._vm);
}
}
});
I'm using Vue 3 and Vue.prototype.$foo seems to have been removed for this version. I also found that in my version of VueX there is no this._vm.
I explored the Provide / Inject method which is recommended by the Vue 3 docs. This worked nicely for accessing globals from within my components, but I couldn't access them from within store.
The solution I went for was to use globalProperties on the Vue object and standard properties on store, and set them just before mounting the app.
main.js:
import store from './store/index';
import App from './App.vue';
// Load custom globals
import conf from '#/inc/myapp.config';
const app = createApp(App)
.use(store);
// Register globals in app and store
app.config.globalProperties.$conf = conf;
store.$conf = conf;
app.mount('#app');
What I like about this is that I can access the globals in the same way in both store and components.
In a component:
export default {
data() {
return {
};
},
created() {
console.log( this.$conf.API_URL );
},
}
...and you can access this.$conf.API_URL in the same way from actions, mutations and getters.
Once I'd found this solution I no longer needed access to the whole Vue instance from within store, but if you need it for some reason you can assign store.$app = app; in the same place in main.js.
You have 2 approaches:
Pass down the property (or even access the _vm property from inside Vuex) as an argument from a component
methods: {
this.$store.dispatch('someAction', this.$API)
}
Declare and export that same variable from another file and consume it from your main.js AND your Vuex file:
// api.js
export const API = "http://localhost:5000/api"
// main.js
import { API } from './api.js
...
Vue.prototype.$API = API
// store.js
import { API } from './api.js
// you can use API now!
Although I would personally lean towards the second, I would not store the API path in Vue at all as I'd rather have the api.js file as a service to perform all ajax calls and consume that file from where I need.
use this._vm
here is why
by default when you access this in vuex store it will point store so it will output something like this
so after that, you see that there is something called _vm in store here it is
so that _vm points to the vue component so to access it you will need to use this._vue
you can better create a getter of the vue instance like
const store = new Vuex.Store({
getters: {
vue(state) {
return this._vm
}
}
});
//so you can use it across your store
store.getters.vue
//Note
//the above way of accessing getter works on non `namespaced` stores
As of recently, under Vuex 4.* and Vue 3.*, this.$app hasn't been defined for the store object. Instead you have Vue Router defined as this.$router.
So for javascript, the way to get app in store would be like so:
The code would now be: router.app = app; and inside, say, an action: let app = this.$router.app;
Is it possible to use callHook in a custom plugin?
I have to register a custom service class for fetching data and the fastest way to do this was by registering my custom class within a module like this (example taken from this Medium post: https://medium.com/swlh/service-classes-using-plugins-in-nuxt-js-32c0f387ecb9):
// plugins/services.plugin.js
import { LoggingService } from '../logging.service'
export default ({ app }, inject) => {
// create an instance of the LoggingService with the prefix 'My App'
const logging = new LoggingService('My App')
// inject the service, making it available in the context, component, store, etc.
inject('logging', logging)
}
Everything works as expected except I can't for the life of me figure it out if I can define my custom hooks in a plugin. I figured if I can get a reference to the nuxt context I'd be able to do it. I did not find any information about whether what I'm trying to do was possible or not.
I initialized i18n translation object once in a component (a first component that loads in the app ). That same object is required In all other components. I don't want to re-initialize it in every component. What's the way around? Making it available to window scope doesn't help as I need to use it in the render() method.
Please suggest a generic solution for these problems and not i18n specific solution.
Beyond React
You might not be aware that an import is global already. If you export an object (singleton) it is then globally accessible as an import statement and it can also be modified globally.
If you want to initialize something globally but ensure its only modified once, you can use this singleton approach that initially has modifiable properties but then you can use Object.freeze after its first use to ensure its immutable in your init scenario.
const myInitObject = {}
export default myInitObject
then in your init method referencing it:
import myInitObject from './myInitObject'
myInitObject.someProp = 'i am about to get cold'
Object.freeze(myInitObject)
The myInitObject will still be global as it can be referenced anywhere as an import but will remain frozen and throw if anyone attempts to modify it.
Example of react state using singleton
https://codesandbox.io/s/adoring-architecture-ru3vt
(see UserContext.tsx)
If using react-create-app
(what I was looking for actually) In this scenario you can also initialize global objects cleanly when referencing environment variables.
Creating a .env file at the root of your project with prefixed REACT_APP_ variables inside does quite nicely. You can reference within your JS and JSX process.env.REACT_APP_SOME_VAR as you need AND it's immutable by design.
This avoids having to set window.myVar = %REACT_APP_MY_VAR% in HTML.
See more useful details about this from Facebook directly:
https://facebook.github.io/create-react-app/docs/adding-custom-environment-variables
Why don't you try using Context?
You can declare a global context variable in any of the parent components and this variable will be accessible across the component tree by this.context.varname. You only have to specify childContextTypes and getChildContext in the parent component and thereafter you can use/modify this from any component by just specifying contextTypes in the child component.
However, please take a note of this as mentioned in docs:
Just as global variables are best avoided when writing clear code, you should avoid using context in most cases. In particular, think twice before using it to "save typing" and using it instead of passing explicit props.
Create a file named "config.js" in ./src folder with this content:
module.exports = global.config = {
i18n: {
welcome: {
en: "Welcome",
fa: "خوش آمدید"
}
// rest of your translation object
}
// other global config variables you wish
};
In your main file "index.js" put this line:
import './config';
Everywhere you need your object use this:
global.config.i18n.welcome.en
Is not recommended but.... you can use componentWillMount from your app class to add your global variables trough it... a bit like so:
componentWillMount: function () {
window.MyVars = {
ajax: require('../helpers/ajax.jsx'),
utils: require('../helpers/utils.jsx')
};
}
still consider this a hack... but it will get your job done
btw componentWillMount executes once before rendering, see more here:
https://reactjs.org/docs/react-component.html#mounting-componentwillmount
Here is a modern approach, using globalThis, we took for our React Native app.
globalThis is now included in...
Modern browsers - MDN documentation
Typescript 3.4 - Handbook documentation
ESLint v7 - Release notes
appGlobals.ts
// define our parent property accessible via globalThis. Also apply the TypeScript type.
var app: globalAppVariables;
// define the child properties and their types.
type globalAppVariables = {
messageLimit: number;
// more can go here.
};
// set the values.
globalThis.app = {
messageLimit: 10,
// more can go here.
};
// Freeze so these can only be defined in this file.
Object.freeze(globalThis.app);
App.tsx (our main entry point file)
import './appGlobals'
// other code
anyWhereElseInTheApp.tsx
const chatGroupQuery = useQuery(GET_CHAT_GROUP_WITH_MESSAGES_BY_ID, {
variables: {
chatGroupId,
currentUserId: me.id,
messageLimit: globalThis.app.messageLimit, // 👈 used here.
},
});
Can keep global variables in webpack i.e. in webpack.config.js
externals: {
'config': JSON.stringify({ GLOBAL_VARIABLE: "global var value" })
}
In js module can read like
var config = require('config')
var GLOBAL_VARIABLE = config.GLOBAL_VARIABLE
Hope this will help.
The best way I have found so far is to use React Context but to isolate it inside a high order provider component.
Maybe it's using a sledge-hammer to crack a nut, but using environment variables (with Dotenv https://www.npmjs.com/package/dotenv) you can also provide values throughout your React app. And that without any overhead code where they are used.
I came here because I found that some of the variables defined in my env files where static throughout the different envs, so I searched for a way to move them out of the env files. But honestly I don't like any of the alternatives I found here. I don't want to set up and use a context everytime I need those values.
I am not experienced when it comes to environments, so please, if there is a downside to this approach, let me know.
Create a file :
import React from "react";
const AppContext = {};
export default AppContext;
then in App.js, update the value
import AppContext from './AppContext';
AppContext.username = uname.value;
Now if you want the username to be used in another screen:
import AppContext from './AppContext';
AppContext.username to be used for accessing it.
For only declaring something, try this. Make sure MyObj is assigned at the proper time for you want to access it in render(), many ways was published before this thread. Maybe one of the simplest ways if undefined then create it does the job.
declare global {
interface Window {
MyObj: any;
}
}
USE CUSTOM HOOKS
It is very simple if you use custom hooks
Refer this link
https://stackoverflow.com/a/73678597/19969598
Full sample usage is available in the above post
This answer is for global part of question not I18N.
I wanted a global variable and function across all components of my application and without child-parent relationship.
This Answer is like a good one; but it was not completely clear to me so i had to test it my way.
I used below approach; not sure if this is a "good or bad practice" or even "off-topic"; but share in case help someone.
Global.jsx
const Global = () => { }
export default Global;
Global.var = 100;
Global.func = () => {
Global.var += 1;
alert(Global.var);
}
MyComponent1.jsx
import Global from "./Global";
import React from "react";
const MyComponent1 = () => {
return ( <h1 onClick={Global.func}>COM1: {Global.var}</h1>)
}
export default MyComponent1;
MyComponent2.jsx
import Global from "./Global";
import React from "react";
const MyComponent2 = () => {
return ( <h1 onClick={Global.func}>COM2: {Global.var}</h1>)
}
export default MyComponent2;
And anywhere like index.js
root.render(
<div>
.
.
.
<MyComponent1/>
<MyComponent1/>
<MyComponent2/>
<MyComponent2/>
.
.
.
</div>
);
Note: This way you have access to a global function or variable; but provided sample cannot update (render) screen itself cause no state or prop has been changed.
We can change the solution like this and keep ref of our components or DOM objects in our Global Zone like this (Not that i do not know its a good practice or even the worst case; so its on your own):
Global.jsx
const Global = () => { }
export default Global;
Global.var = 100;
Global.refs = [];
Global.inc = () => {
Global.var += 1;
Global.refs.forEach(ref => {
ref.current.innerText = Global.var;
});
}
MyComponent1.jsx, MyComponent2.jsx, ...
import Global from "./Global";
import React, { createRef } from "react";
const MyComponent1 = () => {
const ref = createRef();
Global.refs.push(ref);
return (<div onClick={Global.inc}>
<h2>COM1:</h2>
<h3 ref={ref} >{Global.var}</h3>
</div>);
};
export default MyComponent1;
I don't know what they're trying to say with this "React Context" stuff - they're talking Greek, to me, but here's how I did it:
Carrying values between functions, on the same page
In your constructor, bind your setter:
this.setSomeVariable = this.setSomeVariable.bind(this);
Then declare a function just below your constructor:
setSomeVariable(propertyTextToAdd) {
this.setState({
myProperty: propertyTextToAdd
});
}
When you want to set it, call this.setSomeVariable("some value");
(You might even be able to get away with this.state.myProperty = "some value";)
When you want to get it, call var myProp = this.state.myProperty;
Using alert(myProp); should give you some value .
Extra scaffolding method to carry values across pages/components
You can assign a model to this (technically this.stores), so you can then reference it with this.state:
import Reflux from 'reflux'
import Actions from '~/actions/actions'
class YourForm extends Reflux.Store
{
constructor()
{
super();
this.state = {
someGlobalVariable: '',
};
this.listenables = Actions;
this.baseState = {
someGlobalVariable: '',
};
}
onUpdateFields(name, value) {
this.setState({
[name]: value,
});
}
onResetFields() {
this.setState({
someGlobalVariable: '',
});
}
}
const reqformdata = new YourForm
export default reqformdata
Save this to a folder called stores as yourForm.jsx.
Then you can do this in another page:
import React from 'react'
import Reflux from 'reflux'
import {Form} from 'reactstrap'
import YourForm from '~/stores/yourForm.jsx'
Reflux.defineReact(React)
class SomePage extends Reflux.Component {
constructor(props) {
super(props);
this.state = {
someLocalVariable: '',
}
this.stores = [
YourForm,
]
}
render() {
const myVar = this.state.someGlobalVariable;
return (
<Form>
<div>{myVar}</div>
</Form>
)
}
}
export default SomePage
If you had set this.state.someGlobalVariable in another component using a function like:
setSomeVariable(propertyTextToAdd) {
this.setState({
myGlobalVariable: propertyTextToAdd
});
}
that you bind in the constructor with:
this.setSomeVariable = this.setSomeVariable.bind(this);
the value in propertyTextToAdd would be displayed in SomePage using the code shown above.
I hope this question is not a duplicate. If it is so, please point me to the right directions.
I have a Vue application which is compiled with Webpack#NPM. I use mixin to propagate a property (roles) across all components. I update it with an ajax call from app instantiation. Problem is roles only updates for the <Root> component, not for all others.
////////////////////////
// app.js
////////////////////////
// import
window.axios = require('axios')
import Vue from 'vue'
import VueRouter from 'vue-router'
import routes from './routes.js'
// mixin
Vue.mixin({
data: function () {
return {
// property in question
roles: [],
}
},
methods: {
getRoles: function() { //////////// this method updates property.
// get
axios.get('/api/vcr/admin/roles')
// process
.then(response=>{
this.roles = response.data.data;
})
// error?
.catch(error=>{
this.toast(error.response.data.message);
})
},
},
});
// router
const router = new VueRouter({
mode: 'history',
routes: routes,
});
// app
const app = new Vue({
el: '#app',
components: { App: require('./views/App').default },
router,
base: '/saas/vcr/admin',
created: function() { ////////////// I update it here
this.getRoles();
}
});
////////////////////////
// Foo.vue
////////////////////////
<script>
export default {
mounted: function() {
console.log(this.roles) ////// returns an empty array
}
}
</script>
Do you know how to make roles reactive?
The global mixin you have created does not call the function that populates the roles property, it relies on the inheriting instance to do so. In your app "root" instance, you're doing that in the created life-cycle hook which calls getRoles on the mixin, but in the component Foo you are not calling it, so it will have its default empty value. The roles property is not shared, each component will get its own copy of it and will need to be populated.
You could change the mixin to do this for you, by adding the life-cycle created hook as you have done in the root instance. Here's an example of that. Note implementing that in the mix-in does not prevent or override later life cycle hooks from being run on the instances it is merged into. But, it will in your case make an API call for every component instance that is created, which probably isn't desirable.
If you want to only populate it once then share it between all components, it might make more sense to use Vuex and have a global state where roles is populated centrally and shared between all components in a reactive way.
Actually i want to know where to store common components methods in #NUXT.JS.
things which i have tried.
--> Storing common code in middleware (its use-less) because according to my knowledge middleware is only capable of handling request and response to server.
methods: {
// states methods.
SwitchManager: function (__dataContainer, __key, __value) {
// stand alone debugger for this module.
let debug = __debug('computed:_3levelSwitch')
// debug showing function loaded.
debug('(h1:sizeCheck) creating switch..')
// switch.
switch (__key) {
// fake allow set value to true of given key
default:
this[__dataContainer][__key][__value] = true
break
}
return this[__dataContainer][__key][__value]
},
SizeCheck: function (__size) {
// stand alone debugger for this module.
let debug = __debug('tags:p')
// debug showing function loaded.
debug('(p:sizeCheck) checking..')
// init switch.
this.SwitchManager('pill', 'size', __size)
},
StateCheck: function (__state) {
// stand alone debugger for this module.
let debug = __debug('tags:h1')
// debug showing function loaded.
debug('(h1:sizeCheck) checking..')
// init switch.
this.SwitchManager('pill', 'state', __state)
}
},
created () {
// h1 tag size check
this.SizeCheck(this.size)
this.StateCheck(this.state)
}
I go for mixins like with plain vue.js. Only difference - for global mixins - I include them as a plugin, but first:
Non global mixins
I would create an extra folder for my mixins. For example in a /mixins/testMixin.js
export default {
methods: {
aCommonMethod () {}
}
}
Then import in a layout, page or component and add it via the mixins object:
<script>
import commonMixin from '~/mixins/testMixin.js'
export default {
mixins: [commonMixin]
}
</script>
Global mixins
For example in a new file plugins/mixinCommonMethods.js:
import Vue from 'vue'
Vue.mixin({
methods: {
aCommonMethod () {}
}
})
Include that file then in nuxt.config.js
plugins: ['~/plugins/mixinCommonMethods']
After that you would have the method everywhere available and call it there with this.commonMethod(). But here an advice from the vue.js docs:
Use global mixins sparsely and carefully, because it affects every single Vue instance created, including third party components. In most cases, you should only use it for custom option handling like demonstrated in the example above. It’s also a good idea to ship them as Plugins to avoid duplicate application.
Inject in $root & context
Another possibility would be to Inject in $root & context