Vue Micro Services

📖 Read the documentation

> A simple mechanism to transform a monolithic Vue application into an application based on Micro Services architecture.

Inspiration

Combination of Vue and NuxtJS frameworks gives us the opportunity to build any web application we want.
Unfortunately, application built on this approach is monolithic and we cannot extend its behavior. Of course we can extend project with some elements, but these are small fragments that do not add much. In addition, NuxtJS forces developers to have a specific directory structure (page, middleware, store, etc.). This gives us a rigid application built on specific principles.

VueMS gives the possibility to divide the application into micro parts that use all Vue + NuxtJS mechanisms, but do not have their limitations. Structure of these parts is identical to the monolithic application, however each module can operate separately, communicate and interact with one another. Modules can be both small elements (single component, plugin) and complex structures (components, plugins, middleware, store, pages).

Advantages of VueMS:

- Each module can have its own business context communicating separately with the backend application.
- Modules can be turned active or inactivate anytime which allows to customize the application for each client individually.
- Modules can be loaded locally within the application and downloaded from external servers ([npm][npm], [Verdaccio][verdaccio]).
- Thanks to having modules on external servers, we can version them, therefore the modules are independent and easy to expand.
- The customer can upgrade any package or replace it with another one.

---

Detailed Start

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- [Vue.js][vue] (v2.x)
- [Nuxt.js][nuxt] (v2.x)
- [Nuxt Router][router]

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- [Vuex][vuex] - optionally
- [i18n][i18n] - optionally

---

Setup

#### 1. Add @ergonode/vuems dependency to your project.

``bash
npm install @ergonode/vuems


or


yarn add @ergonode/vuems
`

#### 2. Add @ergonode/vuems to the buildModules section in the nuxt.config.js file.

`js
export default {
...
buildModules: [
['@ergonode/vuems', { / module options / }]
],
...
}
`

##### Using top level options

`js
export default {
...
buildModules: [
'@ergonode/vuems'
],
vuems: {
/ module options /
},
...
}
`
---


Options

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- Type: Object
- Default: { npm:[], local: [] }

Object with all loaded modules.

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- Type: Array
- Default: []

Array with required module names.

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- Type: String
- Default: modules

Local modules directory name.

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- Type: String
- Default: vendor

Npm modules directory name. Directory is temporary and used by symbolic link.

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- Type: String
- Default: node_modules

Directory where installed npm modules are to be found.

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- Type: Boolean
- Default: true

If Vuex library is used.

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- Type: Boolean
- Default: false

If i18n plugin is used.

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- Type: Boolean
- Default: false

Is development mode on.

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- Type: Boolean
- Default: false

Log all loaded modules.

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- Type: Boolean
- Default: true

Log module process.

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- Type: Object
- Default:
`
{
assets: 'assets',
components: 'components',
config: 'config',
layouts: 'layouts',
middleware: 'middleware',
pages: 'pages',
plugins: 'plugins',
store: 'store',
}
`

Directory structure for module.

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`js
vuems: {
required: [
'@my/core',
],
modules: {
local: [
'@my/core',
'@my/authentication',
],
npm: [
'@test/users',
'@test2/import'
]
},
isDev: process.env.NODE_ENV !== 'production',
}
`
---

Module creating

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Modules are based on mechanisms Nuxt Modules, but they have no restrictions on the structure. The module can have any structure, which means it can be a single functionality or a large and complex business logic. We divide modules at our discretion and it is also our decision what structure they will have.

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Modules can be divided into two types. The type determines the place from which the module is loaded.
- local: Modules placed locally in the project in the default modules directory. These modules are only available in the project and are fully modifiable.
:warning: Changing the default directory for local modules (modulesDir option)
- npm: Modules hosted on external servers (npm). Module is available when we install the package in the project (npm i module-name). These modules are unmodifiable and they are updated only by upgrading the npm package version.
:warning: Changing the directory for installed npm packages (nodeModulesDir option).
:warning: Changing the directory attached to the symbolic link (vendorDir option).

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#### Local
The names of local modules are determined based on the directory structure. The adopted and recommended directory structure is based on the concept npm scope.
`
modules/
|-- @test/
|-- my-local-module/
|-- users/
`
#### Npm
The names of the npm modules are consistent with the approach of creating npm packages.

Example:
`js
modules: {
local: [
'@test/my-local-module',
'users',
],
npm: [
'@npm/npm-module',
],
}
`

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Each module needs several things to work properly:

#### index.js entry file:

In the project directory we create an entry file called index.js, needed to run the module.
- index.js is created according to the Nuxt Modules rules,
- The default exported function must be asynchronous,
- We can add two additional functions:
- beforeModule() - asynchronous function run before the module is loaded,
- afterModule() - synchronous function started after the module is loaded,

`js
export async function beforeModule() {
// run before loding module
}
export default async function () {
// module logic
}
export async function afterModule() {
// run after loding module
}
`

#### config directory:
Module must have a config directory with index.js file. All available configurations can be placed in this directory.

##### Configurations:
- index.js: Main configuration file exporting object:
- name: Module name
- Type: String
- Required: true :warning:
- aliases: Module aliases needed for easy communication between modules
- Type: Object
- Required: true :warning:
- relations: Modules relations. Modules in this array are needed for proper module operation.
- Type: Array
- Required: false
- replacements: Component replacements. Replace any component from any module with your own.
- Type: Object
- Required: false
- plugins: Module plugins loaded globally.
- Type: Array
- Required: false
- css: Module css loaded globally.
- Type: Array
- Required: false

Example:
`js
export default {
name: '@test/core',
aliases: {
'@Core': '/',
},
replacements: {
'@Core/components/coreComponent': '/components/myComponent',
},
relations: [
'@test/messages',
],
plugins: [
{ ssr: true, src: './plugins/axios' },
],
css: [
'./assets/scss/reset.scss',
]
};
`

- routes.js: Main routing configuration file for the module. Is closely related with Nuxt Router mechanism.

Example:
`js
const Page = () => import('@Core/pages/settings/index').then(m => m.default || m);
const Tab = () => import('@Core/components/tab').then(m => m.default || m);

export default [
{
name: 'settings',
path: '/settings',
component: Page,
children: [
{
name: 'settings-main',
path: 'main',
component: Tab,
},
],
},
];
`

- extends.js: Mechanisms extending other modules.
- extendComponents: You can extend components from one module to components from another.
- Type: Object
- Required: false

Example:
`js
// Definition
const Navigation: () => import('@Notifications/components/Navigation');

export default {
extendComponents: {
NAVIGATION_BAR: [
{
component: Navigation,
props: {},
},
],
},
};
`
The global this.$getExtendSlot() function is used to download the component.
`js
// Use in other module


`
- extendRoutesChildren: You can extend routing in any module.
- Type: Array
- Required: false

Example:
`js
const TestSettingsTab = () => import('@Test/components/SettingsTab').then(m => m.default || m);

export default {
extendRoutesChildren: [
{
name: 'settings', // existing router name what we want extend
children: [ // array with router to extend
{
name: 'settings-test',
path: 'test',
component: TestSettingsTab,
},
],
}
];
}
`
- dictionaries: You can extend dictionaries.
- Type: Array
- Required: false

Example:
`js
export default {
dictionaries: [
{
stateProp: 'currencies',
dataFormat: {},
requestPath: '/dictionary/currencies',
},
]
}
`
- extendStore: You can extend the existing Vuex store.
- Type: Object
- Required: false

Example:
`js
const TestStore = () => import('@Test/extends/store/test');

export default {
extendStore: {
Test: TestStore,
},
}
`
If we have existing Test store and we want extend it.

- extendMethods: You can insert any method from module
- Type: Object
- Required: false

Example:
`js
// Definition
export default {
extendMethods: {
'@Test/store/test/action': () => {
console.log('test');
}
},
}
`
The global this.$getExtendMethod() function is used for call extended methods.
`js
// Use in other module
export default {
create({ state }) {
...
this.$getExtendMethod('@Test/store/test/action');
...
}
}
``

Example application

- Ergonode

[npm]: https://verdaccio.org/
[verdaccio]: https://verdaccio.org/
[vue]: https://vuejs.org
[nuxt]: https://nuxtjs.org/
[router]: https://github.com/nuxt-community/router-module
[vuex]: http://vuex.vuejs.org
[i18n]: https://i18n.nuxtjs.org/