In my Nuxt app I'm registering app services in a plugin file (e.g. /plugins/services.js) like this...
import FeatureOneService from '#/services/feature-one-service.js'
import FeatureTwoService from '#/services/feature-two-service.js'
import FeatureThreeService from '#/services/feature-three-service.js'
import FeatureFourService from '#/services/feature-four-service.js'
import FeatureFiveService from '#/services/feature-five-service.js'
export default (ctx, inject) => {
inject('feature1', new FeatureOneService(ctx))
inject('feature2', new FeatureTwoService(ctx))
inject('feature3', new FeatureThreeService(ctx))
inject('feature4', new FeatureFourService(ctx))
inject('feature5', new FeatureFiveService(ctx))
}
After doing this I can access any of my service on vue instance like this.$feature1.someMethod()
It works but I've once concern, that is, this approach loads all services globally. So whatever page the user visits all these services must be loaded.
Now I've 20+ such services in my app and this does not seem optimal approach to me.
The other approach I was wondering is to export a singleton instance within each service class and import this class instance in any component which needs that service.
So basically in my service class (e.g. feature-one-service.js) I would do like to do it like this..
export default new FeatureOneService() <---- I'm not sure how to pass nuxt instance in a .js file?
and import it my component where it is required like so...
import FeatureOneService from '#/services/feature-one-service.js'
What approach do you think is most feasible? if its the second one, then how to pass nuxt instance to my singleton class?
Yep, loading everything globally is not optimal in terms of performance.
You will need to either try to use JS files and pass down the Vue instance there.
Or use mixins, this is not optimal but it is pretty much the only solution in terms of reusability with Vue2.
Vue3 (composition API) brings composables, which is a far better approach regarding reusability (thing React hooks).
I've been struggling a lot with it and the only solution is probably to inject services to the global Vue instance at the component/page level during the initialisation (in created hook), another option is to do that in the middleware (or anywhere else where you have access to the nuxt context. Otherwise you won't be able to pass nuxt context to the service.
I usually set up services as classes, call them where necessary, and pass in the properties of the context which the class depends on as constructor arguments.
So for example, a basic MeiliSearchService class might look like:
export class MeilisearchService {
#client: MeiliSearch
constructor($config: NuxtRuntimeConfig) {
super()
this.#client = new MeiliSearch({
host: $config.services.meilisearch.host,
apiKey: $config.services.meilisearch.key
})
}
...
someMethod() {
let doSomething = this.#client.method()
...
}
...
}
Then wherever you need to use the service, just new up an instance (passing in whatever it needs) and make it available to the component.
data() {
const meiliSearchService = new MeiliSearchService(this.$config)
return {
meiliSearchService,
results,
...
}
},
methods: {
search(query) {
...
this.results = this.meiliSearchService.search(query)
...
}
}
As I'm sure you know, some context properties are only available in certain Nuxt life-cycle hooks. I find most of what I need is available everywhere, including $config, store, $route, $router etc.
Don't forget about Vue's reactivity when using this approach. For example, using a getter method on your service class will return the most recent value only when explicitly called. You can't, for example, stick the getter method in a computed() property and expect reactivty.
<div v-for='result in latestSearchResults'>
...
</div>
...
computed: {
latestSearchResults() {
return this.#client.getLatestResults()
}
}
Instead, call the method like:
methods: {
getLatestResults() {
return this.#client.getLatestResults()
}
}
Related
I recently came across this blog post: Stop using Page Objects and Start using App Actions. It describes an approach where the application exposes its model so that Cypress can access it in order to setup certain states for testing.
Example code from the link:
// app.jsx code
var model = new app.TodoModel('react-todos');
if (window.Cypress) {
window.model = model
}
I'd like to try this approach in my VueJS application but I'm struggling with how to expose "the model".
I'm aware that it's possible to expose the Vuex store as described here: Exposing vuex store to Cypress but I'd need access to the component's data().
So, how could I expose e.g. HelloWorld.data.message for being accessible from Cypress?
Demo application on codesandbox.io
Would it be possible via Options/Data API?
Vue is pretty good at providing it's internals for plugins, etc. Just console.log() to discover where the data sits at runtime.
For example, to read internal Vue data,
either from the app level (main.js)
const Vue = new Vue({...
if (window.Cypress) {
window.Vue = Vue;
}
then in the test
cy.window().then(win => {
const message = win.Vue.$children[0].$children[0].message;
}
or from the component level
mounted() {
if (window.Cypress) {
window.HelloWorld = this;
}
}
then in the test
cy.window().then(win => {
const message = win.HelloWorld.message;
}
But actions in the referenced article implies setting data, and in Vue that means you should use Vue.set() to maintain observability.
Since Vue is exposed on this.$root,
cy.window().then(win => {
const component = win.HelloWorld;
const Vue = component.$root;
Vue.$set(component, 'message', newValue);
}
P.S. The need to use Vue.set() may go away in v3, since they are implementing observability via proxies - you may just be able to assign the value.
Experimental App Action for Vue HelloWorld component.
You could expose a setter within the Vue component in the mounted hook
mounted() {
this.$root.setHelloWorldMessage = this.setMessage;
},
methods: {
setMessage: function (newValue) {
this.message = newValue;
}
}
But now we are looking at a situation where the Cypress test is looking like another component of the app that needs access to state of the HelloWorld.
In this case the Vuex approach you referenced seems the cleaner way to handle things.
How can I access my store from my plugin? Console returns undefined.
import store from './store';
export default {
install(vue, opts){
Vue.myGlobalFunction = function(){
console.log(store);
}
}
}
I recently had to do this too to make a pouchDb plugin, and came up with a new way.
When you create your first Vue object, you can do this.
import PouchDb from '#/pouch_db/PouchDbPlugin'
let DefaultVue = Vue.extend({
components: {App},
store,
created () {
Vue.use(PouchDb, this.$store) // Create it by passing in the store you want to use
}
})
My plugin adds an additional store, and it's own mutations and getters.
export default {
install (Vue, store) {
store.registerModule('PouchDb', pds)
const pouchDb = new PouchDb(store)
Vue.pouchDb = pouchDb
Vue.prototype.$pouchDb = pouchDb
}
}
Inside the constructor, I store the store
class PouchDb {
constructor (store) {
this.store = store
// ... etc.
}
// ... more functions
}
And then use it in other functions
class PouchDb {
// ... constructor and other functions
async addSync (docId) {
this.store.dispatch('PouchDb/addSync', docId)
}
}
It's a bit of a cheat to pass in the store, but seems to work nicely. It's usable throughout the app like this
// Inside vuex store
Vue.pouchDb.addSync(// ...etc)
// inside component
this.$pouchDb.removeSync(// ...etc)
See official guide here where it states
A Vue.js plugin should expose an install method. The method will be called with the Vue constructor as the first argument, along with possible options:
So you can do this, very easily.
Vue.use( {
install(Vue){
Vue.prototype.$something = function (){
this.$store...etc
}
}
} )
To use, simply do this.$something() in a components methods/computed etc, or directly in the component markup as {{$something()}}
This will remove the plugin needing to know where the store actually resides, while still allowing you to utilize the store within the plugin.
This is because it will inherit the scope of whatever component utilizes it, thus providing access to all of the components instance properties, including things like $store, $router as well any of it's local properties such as computed properties, parents etc. Essentially the plugin functions as if it is directly a part of the component (eg if you used it as a mixin).
For Vue 3
Incase if you wonder, how to do it in Vue 3, You can use the following.
plugin.js
export default {
install(app) { // app instance
console.log(app.config.globalProperties.$store)
}
}
main.js
import store from './pathtostore'
import plugin from './plugin'
createApp(...).use(store).use(plugin)
When app starts, you import your store and "append" it to Vue, globally.
Now, if you use() your plugin, the first parameter of install() is always Vue itself, and in this moment Vue already has access to the store, in the install method you can simply start
install(vue, opts) {
... here your can acces to vue.$store ....
}
I have an Aurelia app using Aurelia Store. I'm having some trouble when using the #connectTo decorator in an Aurelia pipeline step.
I have added the following step to my config pipeline:
config.addPipelineStep('authorize', AuthorizeStep);
And this step looks like:
#connectTo()
export class AuthorizeStep {
state: State;
run(navigationInstruction, next) {
if (navigationInstruction.getAllInstructions().find(x => x.config.isAdmin))
{
if (!this.state.user.isAdmin) {
return next.cancel();
}
}
return next();
}
}
However, my state is always undefined. Looking at other parts of my project, I can see the state and user are being populated, but it seems like in this AuthorizeStep it doesn't seem to work.
I think this issue may be due to the fact that my AuthorizeStep doesn't have a bind lifecycle method, but if so, what can I do about this?
The maintainers of Aurelia responded (only after I raised an issue on their GitHub) here.
Basically, as the bind lifecycle does not exist within this class, the #connectTo decorator won't work. Instead, I will need to manually inject the Store and subscribing to the state.
In my Vuex setup, the store is currently structured like this:
store
- modules
- common_data
- index.js
- mutations.js
- actions.js
- getters.js
Now, one of the actions inside actions.js is defined as:
populateTimeZones(context) {
var baseUrl = context.getters.getApiBaseUrl;
this.$http.get(baseUrl + '/time-zones')
.then(function (res){
if(res.status == 'ok'){
this.$store.commit('SET_TIME_ZONES', res.info.timeZones);
} else {
alert('An error occurred. Please try again!');
return;
}
}.bind(this));
}
I think the Vue instance is not available here, which is causing the action to fail with the error: Cannot read property 'get' of undefined. I've tried other combinations like this.axios and vue.axios but the result is same.
Am I doing something wrong? What is the common pattern for handling such cases?
You won't be able to access the Vue instance without passing it through or creating a new one.
A simple way to do what you want is to simply pass your this through to your action this.$store.dispatch('populateTimeZones', this), then change your method signiture to populateTimeZones({ context }, vueInstance). This would then allow you to access vueInstance.$http.
Another idea would be something called vue-inject which is a DI container for Vue. It would allow you to register axios as a service and then simply call VueInjector.get('axios') whenever you need it. On the Vue component itself you can do dependencies: ['axios'] and then use like this.axios. Not so much an issue in this case but helpful when you have lots of services doing work for you
Currently I'm using Babel to write a Node.js backend in ES6. Unfortunately I encountered a strange behaviour when extending a specific class. Some of my methods, defined in the extending class, are undefined. Unless I use the ES7 syntax to bind them to a property.
This is the actual code that gives me this strange behaviour:
import { Router } from 'express';
class MyCustomRouter extends Router
{
constructor() {
super();
this.methodWorks(); // works like a charm.
this.methodDoesnt(); // throws TypeError: _this.methodDoesnt is not a function
}
methodWorks = () => {
// some content
}
methodDoesnt() {
// some content
}
}
This is actually extends the Router from the expressjs library. So right now I'm just curious if someone could explain this behaviour and/or if there is a way to fix this.
I went looking inside the code of ExpressJS itself to find some explanation. Apparently they like to return a whole new and different context from the Router's constructor. Which explains why this is totally different and not containing my methods...