initExtend() — vue Function Reference

Architecture documentation for the initExtend() function in extend.ts from the vue codebase.

Function typescript CoreRuntime VirtualDOM calls 3 called by 1

Entity Profile

CoreRuntime→ VirtualDOM→ initExtend() — vue Function Reference

Dependency Diagram

graph TD
  ce425d9f_05ad_8df9_9c70_37c35a2bdb0e["initExtend()"]
  a14b0815_48fb_998a_d3d7_ac867ed1d7f9["extend.ts"]
  ce425d9f_05ad_8df9_9c70_37c35a2bdb0e -->|defined in| a14b0815_48fb_998a_d3d7_ac867ed1d7f9
  ee699f75_f5be_8f7a_91c2_18232c62b421["initGlobalAPI()"]
  ee699f75_f5be_8f7a_91c2_18232c62b421 -->|calls| ce425d9f_05ad_8df9_9c70_37c35a2bdb0e
  16abdeb5_17d6_b741_ca16_dfc41a7d0df5["getComponentName()"]
  ce425d9f_05ad_8df9_9c70_37c35a2bdb0e -->|calls| 16abdeb5_17d6_b741_ca16_dfc41a7d0df5
  c750fd7d_92c7_85b0_ab1c_c459424e4fb5["initProps()"]
  ce425d9f_05ad_8df9_9c70_37c35a2bdb0e -->|calls| c750fd7d_92c7_85b0_ab1c_c459424e4fb5
  bbde495f_48f3_a910_410f_28718d2c8ee1["initComputed()"]
  ce425d9f_05ad_8df9_9c70_37c35a2bdb0e -->|calls| bbde495f_48f3_a910_410f_28718d2c8ee1
  style ce425d9f_05ad_8df9_9c70_37c35a2bdb0e fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

src/core/global-api/extend.ts lines 8–80

export function initExtend(Vue: GlobalAPI) {
  /**
   * Each instance constructor, including Vue, has a unique
   * cid. This enables us to create wrapped "child
   * constructors" for prototypal inheritance and cache them.
   */
  Vue.cid = 0
  let cid = 1

  /**
   * Class inheritance
   */
  Vue.extend = function (extendOptions: any): typeof Component {
    extendOptions = extendOptions || {}
    const Super = this
    const SuperId = Super.cid
    const cachedCtors = extendOptions._Ctor || (extendOptions._Ctor = {})
    if (cachedCtors[SuperId]) {
      return cachedCtors[SuperId]
    }

    const name =
      getComponentName(extendOptions) || getComponentName(Super.options)
    if (__DEV__ && name) {
      validateComponentName(name)
    }

    const Sub = function VueComponent(this: any, options: any) {
      this._init(options)
    } as unknown as typeof Component
    Sub.prototype = Object.create(Super.prototype)
    Sub.prototype.constructor = Sub
    Sub.cid = cid++
    Sub.options = mergeOptions(Super.options, extendOptions)
    Sub['super'] = Super

    // For props and computed properties, we define the proxy getters on
    // the Vue instances at extension time, on the extended prototype. This
    // avoids Object.defineProperty calls for each instance created.
    if (Sub.options.props) {
      initProps(Sub)
    }
    if (Sub.options.computed) {
      initComputed(Sub)
    }

    // allow further extension/mixin/plugin usage
    Sub.extend = Super.extend
    Sub.mixin = Super.mixin
    Sub.use = Super.use

    // create asset registers, so extended classes
    // can have their private assets too.
    ASSET_TYPES.forEach(function (type) {
      Sub[type] = Super[type]
    })
    // enable recursive self-lookup
    if (name) {
      Sub.options.components[name] = Sub
    }

    // keep a reference to the super options at extension time.
    // later at instantiation we can check if Super's options have
    // been updated.
    Sub.superOptions = Super.options
    Sub.extendOptions = extendOptions
    Sub.sealedOptions = extend({}, Sub.options)

    // cache constructor
    cachedCtors[SuperId] = Sub
    return Sub
  }
}