Vuex 4 — Modules Namespace. Vuex 4 is in beta and it’s subject to…
By: John Au-Yeung
Tags: Programming, Web Development, Technology, Software Development, JavaScript

Photo by Daniel Jerez on Unsplash

Vuex 4 is in beta and it’s subject to change.

Vuex is a popular state management library for Vue.

Vuex 4 is the version that’s made to work with Vue 3.

In this article, we’ll look at how to use Vuex 4 with Vue 3.

Accessing Global Assets in Namespaced Modules

We can access global assets in namespaced modules.

For example, we can write:

<!DOCTYPE html>

<html lang="en">

<head>

<script src="https://unpkg.com/vue@next"></script>

<script src="https://unpkg.com/vuex@4.0.0-beta.4/dist/vuex.global.js"></script>

<title>App</title>

</head>

<body>

<div id="app">

<button @click="this['moduleA/increment']">increment</button>

<p>{{this['moduleA/doubleCount']}}</p>

</div>

<script>

const moduleA = {

state: () => ({

count: 0

}),

mutations: {

increment(state) {

state.count++;

}

},

actions: {

increment({ commit, dispatch }) {

commit("increment");

commit("someAction", null, { root: true });

}

},

getters: {

doubleCount(state) {

return state.count * 2;

}

}

}; const store = new Vuex.Store({

mutations: {

someAction(state) {

console.log("someAction");

}

},

modules: {

moduleA: {

namespaced: true,

...moduleA

}

}

});

const app = Vue.createApp({

methods: {

...Vuex.mapActions(["moduleA/increment"])

},

computed: {

...Vuex.mapGetters(["moduleA/doubleCount"])

}

});

app.use(store);

app.mount("#app");

</script>

</body>

</html>

We have the increment action that commits the someAction mutation from the root namespace.

Therefore, when we dispatch the moduleA/increment action, we should see 'someAction' logged.

We called commit with an object with the root: true property to set make it dispatch the root mutation.

We can do the same with actions. For example, we can write:

<!DOCTYPE html>

<html lang="en">

<head>

<script src="https://unpkg.com/vue@next"></script>

<script src="https://unpkg.com/vuex@4.0.0-beta.4/dist/vuex.global.js"></script>

<title>App</title>

</head>

<body>

<div id="app">

<button @click="this['moduleA/increment']">increment</button>

<p>{{this['moduleA/doubleCount']}}</p>

</div>

<script>

const moduleA = {

state: () => ({

count: 0

}),

mutations: {

increment(state) {

state.count++;

}

},

actions: {

increment({ commit, dispatch }) {

commit("increment");

dispatch("someOtherAction", null, { root: true });

}

},

getters: {

doubleCount(state) {

return state.count * 2;

}

}

}; const store = new Vuex.Store({

mutations: {

someAction(state) {

console.log("someAction");

}

},

actions: {

someOtherAction({ commit }) {

commit("someAction");

}

},

modules: {

moduleA: {

namespaced: true,

...moduleA

}

}

});

const app = Vue.createApp({

methods: {

...Vuex.mapActions(["moduleA/increment"])

},

computed: {

...Vuex.mapGetters(["moduleA/doubleCount"])

}

});

app.use(store);

app.mount("#app");

</script>

</body>

</html>

We called dispatch with an object with the root: true property to set make it dispatch the root action.

We can access root getters with the rootGetters property.

To do that, we write:

<!DOCTYPE html>

<html lang="en">

<head>

<script src="https://unpkg.com/vue@next"></script>

<script src="https://unpkg.com/vuex@4.0.0-beta.4/dist/vuex.global.js"></script>

<title>App</title>

</head>

<body>

<div id="app">

<button @click="this['moduleA/increment']">increment</button>

<p>{{this['moduleA/doubleCount']}}</p>

</div>

<script>

const moduleA = {

state: () => ({

count: 0

}),

mutations: {

increment(state) {

state.count++;

}

},

actions: {

increment({ commit, dispatch, rootGetters }) {

console.log("increment", rootGetters.one);

commit("increment");

}

},

getters: {

doubleCount(state, getters, rootState, rootGetters) {

console.log("doubleCount", rootGetters.one);

return state.count * 2;

}

}

}; const store = new Vuex.Store({

getters: {

one(state) {

return 1;

}

},

modules: {

moduleA: {

namespaced: true,

...moduleA

}

}

});

const app = Vue.createApp({

methods: {

...Vuex.mapActions(["moduleA/increment"])

},

computed: {

...Vuex.mapGetters(["moduleA/doubleCount"])

}

});

app.use(store);

app.mount("#app");

</script>

</body>

</html>

We have a one root getter method in the store’s root.

Then we have the rootGetters property in the object parameter of the increment method.

We can get the getter’s return value with from the rootGetters.one property.

Other getters can get the value from the rootGetters parameter.

Conclusion

We can namespace our store so that we divide our store into smaller chunks that have their own states.