9 KiB
Vue.js style guide
Linting
We default to eslint-vue-plugin, with the plugin:vue/recommended
.
Please check this rules for more documentation.
Basic Rules
-
The service has its own file
-
The store has its own file
-
Use a function in the bundle file to instantiate the Vue component:
// bad class { init() { new Component({}) } } // good document.addEventListener('DOMContentLoaded', () => new Vue({ el: '#element', components: { componentName }, render: createElement => createElement('component-name'), }));
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Do not use a singleton for the service or the store
// bad class Store { constructor() { if (!this.prototype.singleton) { // do something } } } // good class Store { constructor() { // do something } }
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Use
.vue
for Vue templates. Do not use%template
in HAML.
Naming
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Extensions: Use
.vue
extension for Vue components. Do not use.js
as file extension (#34371). -
Reference Naming: Use PascalCase for their instances:
// bad import cardBoard from 'cardBoard.vue' components: { cardBoard, }; // good import CardBoard from 'cardBoard.vue' components: { CardBoard, };
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Props Naming: Avoid using DOM component prop names.
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Props Naming: Use kebab-case instead of camelCase to provide props in templates.
// bad <component class="btn"> // good <component css-class="btn"> // bad <component myProp="prop" /> // good <component my-prop="prop" />
Alignment
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Follow these alignment styles for the template method:
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With more than one attribute, all attributes should be on a new line:
// bad <component v-if="bar" param="baz" /> <button class="btn">Click me</button> // good <component v-if="bar" param="baz" /> <button class="btn"> Click me </button>
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The tag can be inline if there is only one attribute:
// good <component bar="bar" /> // good <component bar="bar" /> // bad <component bar="bar" />
-
Quotes
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Always use double quotes
"
inside templates and single quotes'
for all other JS.// bad template: ` <button :class='style'>Button</button> ` // good template: ` <button :class="style">Button</button> `
Props
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Props should be declared as an object
// bad props: ['foo'] // good props: { foo: { type: String, required: false, default: 'bar' } }
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Required key should always be provided when declaring a prop
// bad props: { foo: { type: String, } } // good props: { foo: { type: String, required: false, default: 'bar' } }
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Default key should be provided if the prop is not required. Note: There are some scenarios where we need to check for the existence of the property. On those a default key should not be provided.
// good props: { foo: { type: String, required: false, } } // good props: { foo: { type: String, required: false, default: 'bar' } } // good props: { foo: { type: String, required: true } }
Data
-
data
method should always be a function// bad data: { foo: 'foo' } // good data() { return { foo: 'foo' }; }
Directives
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Shorthand
@
is preferable overv-on
// bad <component v-on:click="eventHandler"/> // good <component @click="eventHandler"/>
-
Shorthand
:
is preferable overv-bind
// bad <component v-bind:class="btn"/> // good <component :class="btn"/>
-
Shorthand
#
is preferable overv-slot
// bad <template v-slot:header></template> // good <template #header></template>
Closing tags
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Prefer self-closing component tags
// bad <component></component> // good <component />
Component usage within templates
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Prefer a component's kebab-cased name over other styles when using it in a template
// bad <MyComponent /> // good <my-component />
Ordering
-
Tag order in
.vue
file<script> // ... </script> <template> // ... </template> // We don't use scoped styles but there are few instances of this <style> // ... </style>
-
Properties in a Vue Component: Check order of properties in components rule.
:key
When using v-for
you need to provide a unique :key
attribute for each item.
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If the elements of the array being iterated have an unique
id
it is advised to use it:<div v-for="item in items" :key="item.id" > <!-- content --> </div>
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When the elements being iterated don't have a unique id, you can use the array index as the
:key
attribute<div v-for="(item, index) in items" :key="index" > <!-- content --> </div>
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When using
v-for
withtemplate
and there is more than one child element, the:key
values must be unique. It's advised to usekebab-case
namespaces.<template v-for="(item, index) in items"> <span :key="`span-${index}`"></span> <button :key="`button-${index}`"></button> </template>
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When dealing with nested
v-for
use the same guidelines as above.<div v-for="item in items" :key="item.id" > <span v-for="element in array" :key="element.id" > <!-- content --> </span> </div>
Useful links:
Vue and Bootstrap
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Tooltips: Do not rely on
has-tooltip
class name for Vue components// bad <span class="has-tooltip" title="Some tooltip text"> Text </span> // good <span v-tooltip title="Some tooltip text"> Text </span>
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Tooltips: When using a tooltip, include the tooltip directive,
./app/assets/javascripts/vue_shared/directives/tooltip.js
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Don't change
data-original-title
.// bad <span data-original-title="tooltip text">Foo</span> // good <span title="tooltip text">Foo</span> $('span').tooltip('_fixTitle');
The JavaScript/Vue Accord
The goal of this accord is to make sure we are all on the same page.
- When writing Vue, you may not use jQuery in your application.
- If you need to grab data from the DOM, you may query the DOM 1 time while bootstrapping your application to grab data attributes using
dataset
. You can do this without jQuery. - You may use a jQuery dependency in Vue.js following this example from the docs.
- If an outside jQuery Event needs to be listen to inside the Vue application, you may use jQuery event listeners.
- We will avoid adding new jQuery events when they are not required. Instead of adding new jQuery events take a look at different methods to do the same task.
- If you need to grab data from the DOM, you may query the DOM 1 time while bootstrapping your application to grab data attributes using
- You may query the
window
object one time, while bootstrapping your application for application specific data (e.g.scrollTo
is ok to access anytime). Do this access during the bootstrapping of your application. - You may have a temporary but immediate need to create technical debt by writing code that does not follow our standards, to be refactored later. Maintainers need to be ok with the tech debt in the first place. An issue should be created for that tech debt to evaluate it further and discuss. In the coming months you should fix that tech debt, with its priority to be determined by maintainers.
- When creating tech debt you must write the tests for that code before hand and those tests may not be rewritten. e.g. jQuery tests rewritten to Vue tests.
- You may choose to use VueX as a centralized state management. If you choose not to use VueX, you must use the store pattern which can be found in the Vue.js documentation.
- Once you have chosen a centralized state-management solution you must use it for your entire application. i.e. Don't mix and match your state-management solutions.