vuex-class-modules

This is yet another package to introduce a simple type-safe class style syntax for your vuex modules, inspired by vue-class-component.

Installation

npm install vuex-class-modules

And make sure to have the

--experimentalDecorators

Both a

commonjs

esm

esm

Usage

Vuex modules can be written using decorators as a class:

// user-module.ts
import { VuexModule, Module, Mutation, Action } from "vuex-class-modules";

@Module
class UserModule extends VuexModule {
  // state
  firstName = "Foo";
  lastName = "Bar";
  // getters
  get fullName() {
    return this.firstName + " " + this.lastName;
  }
  // mutations
  @Mutation
  setFirstName(firstName: string) {
    this.firstName = firstName;
  }
  @Mutation
  setLastName(lastName: string) {
    this.lastName = lastName;
  }
  // actions
  @Action
  async loadUser() {
    const user = await fetchUser();
    this.setFirstName(user.firstName);
    this.setLastName(user.lastName);
  }
}
// register module (could be in any file)
import store from "path/to/store";
export const userModule = new UserModule({ store, name: "user" });

The module will automatically be registered to the store as a namespaced dynamic module when it is instantiated. (The modules are namespaced to avoid name conflicts between modules for getters/mutations/actions.)

The module can then be used in vue components as follows:

// MyComponent.vue
import Vue from "vue";
import { userModule } from "path/to/user-module.ts";

export class MyComponent extends Vue {
  get firstName() {
    return userModule.firstName; // -> store.state.user.firstName
  }
  get fullName() {
    return userModule.fullName; // -> store.getters["user/fullName]
  }
  created() {
    userModule.setFirstName("Foo"); // -> store.commit("user/setFirstName", "Foo")
    userModule.loadUser(); // -> store.dispatch("user/loadUser")
  }
}

What about

rootState

and

rootGetters

?

There are two ways to access other modules within a module, or dispatch actions to other modules.

1. Simply import the instantiated module (suitable if the modules are instantiated in the same file as they are defined):

// my-module.ts

// import the module instance
import { otherModule } from "./other-module";
@Module
class MyModule extends VuexModule {
  get myGetter() {
    return otherModule.foo;
  }
  @Action
  async myAction() {
    await otherModule.someAction();
    // ...
  }
}

1. The other module can be registered through the constructor (suitable if the modules are instantiated elsewhere)

// my-module.ts

// import the class, not the instance
import { OtherModule } from "./other-module";
@Module
export class MyModule extends VuexModule {
  private otherModule: OtherModule;
  constructor(otherModule: OtherModule, options: RegisterOptions) {
    super(options);
    this.otherModule = otherModule;
  }
  get myGetter() {
    return this.otherModule.foo;
  }
  @Action
  async myAction() {
    await this.otherModule.someAction();
    // ...
  }
}
// register-modules.ts
import store from "path/to/store";
import { OtherModule } from "path/to/other-module";
import { MyModule } from "path/to/my-module";
export const otherModule = new OtherModule({ store, name: "otherModule" });
export const myModule = new MyModule(otherModule, { store, name: "myModule" });

The local modules will not be part of the state and cannot be accessed from the outside, so they should always be declared private.

myModule.otherModule; // -> undefined

The

store.watch

function

Vuex can also be used ouside of vue modules. To listen for changes to the state, vuex provides a watch method.

This api is also provided by vuex-class-modules under the method name

$watch

import store from "./store";
import { MyModule } from "./my-module";

const myModule = new MyModule({ store, name: "MyModule" });
myModule.$watch(
  (theModule) => theModule.fullName,
  (newName: string, oldName: string) => {
    // ...
  },
  {
    deep: false,
    immediate: false,
  }
);

and to unwatch:

const unwatch = myModule.$watch(...);
unwatch();

Register options

• name

  [required]: Name of the module

• store

  [required]: The vuex store - which can just be instantiated as empty:

// store.ts
import Vue from "vue";
import Vuex from "vuex";
Vue.use(Vuex);
const store = new Vuex.Store({});

Module options

The module decorator can also accept options:

• generateMutationSetters

  [optional, default=false]: Whether automatic mutation setters for the state properties should be generated, see Generate Mutation Setters.

Example

The vuex shopping cart example rewritten using

vue-class-component

vuex-class-modules

npm run example

Caveats of

this

As for vue-class-component

this

@Module
class MyModule extends VuexModule {
  foo = "bar";

  get someGetter() {
    return 123;
  }
  get myGetter() {
    this.foo; // -> "bar"
    this.someGetter; // -> 123
    this.someMutation(); // undefined, getters cannot call mutations
    this.someAction(); // -> undefined, getters cannot call actions
  }
  @Mutation
  someMutation() {
    /* ... */
  }
  @Mutation
  myMutation() {
    this.foo; // -> "bar"
    this.someGetter; // -> undefined, mutations dont have access to getters
    this.someMutation(); // -> undefined, mutations cannot call other mutations
    this.someAction(); // -> undefined, mutations cannot call actions
  }
  @Action
  async someAction() {
    /* ... */
  }
  @Action
  async myAction() {
    this.foo; // -> "bar"
    this.someGetter; // -> 123
    this.myMutation(); // Ok
    await this.someAction(); // Ok
  }
}

Local Functions

The module can have non-mutation/action functions which can be used inside the module. As for local modules, these functions will not be exposed outside the module and should therefore be private.

this

@Module
class MyModule extends VuexModule {
  get myGetter() {
    return myGetterHelper();
  }
  private myGetterHelper() {
    // same 'this' context as myGetter
  }

  @Mutation
  myMutation() {
    this.myMutationHelper();
  }
  // should be private
  myMutationHelper() { /* ... */}
}
const myModule = new MyModule({ store, name: "myModule });
myModule.myMutationHelper // -> undefined.

Generate Mutation Setters

As I often find myself writing a lot of simple setter mutations like

@Module
class UserModule extends VuexModule {
  firstName = "Foo";
  lastName = "Bar";

  @Mutation
  setFirstName(firstName: string) {
    this.firstName = firstName;
  }
  @Mutation
  setLastName(lastName: string) {
    this.lastName = lastName;
  }
}

a module option

generateMutationSetters

@Module({ generateMutationSetters: true })
class UserModule extends VuexModule {
  firstName = "Foo";
  lastName = "Bar";

  // Auto generated:
  // @Mutation set__firstName(val: any) { this.firstName = val }
  // @Mutation set__lastName(val: any) { this.lastName = val }
  @Action
  async loadUser() {
    const user = await fetchUser();
    this.firstName = user.firstName; // -> this.set__firstName(user.firstName);
    this.lastName = user.lastName; // -> this.set__lastName(user.lastName);
  }
}

NOTE: Setters are only generated for root-level state properties, so in order to update a property of an object you have to use a mutation or replace the entire object:

@Module({ generateMutationSetters: true })
class UserModule extends VuexModule {
  user = {
    id: 123,
    name: "Foo",
  };

  @Mutation
  setUserName() {
    this.user.name = "Bar"; // OK!
  }
  @Action
  async loadUser() {
    this.user.name = "Bar"; // Bad, the state is mutated outside a mutation
    this.user = { ...this.user, name: "Bar" }; // OK!
  }
}

License

MIT