Function convertLegacyProps

packages/runtime-core/src/compat/renderFn.ts:179–227

(
  legacyProps: LegacyVNodeProps | undefined,
  type: any,
)

)

function convertLegacyProps(
  legacyProps: LegacyVNodeProps | undefined,
  type: any,
): (Data & VNodeProps) | null {
  if (!legacyProps) {
    return null
  }

  const converted: Data & VNodeProps = {}

  for (const key in legacyProps) {
    if (key === 'attrs' || key === 'domProps' || key === 'props') {
      extend(converted, legacyProps[key])
    } else if (key === 'on' || key === 'nativeOn') {
      const listeners = legacyProps[key]
      for (const event in listeners) {
        let handlerKey = convertLegacyEventKey(event)
        if (key === 'nativeOn') handlerKey += `Native`
        const existing = converted[handlerKey]
        const incoming = listeners[event]
        if (existing !== incoming) {
          if (existing) {
            converted[handlerKey] = [].concat(existing as any, incoming as any)
          } else {
            converted[handlerKey] = incoming
          }
        }
      }
    } else if (!skipLegacyRootLevelProps(key)) {
      converted[key] = legacyProps[key as keyof LegacyVNodeProps]
    }
  }

  if (legacyProps.staticClass) {
    converted.class = normalizeClass([legacyProps.staticClass, converted.class])
  }
  if (legacyProps.staticStyle) {
    converted.style = normalizeStyle([legacyProps.staticStyle, converted.style])
  }

  if (legacyProps.model && isObject(type)) {
    // v2 compiled component v-model
    const { prop = 'value', event = 'input' } = (type as any).model || {}
    converted[prop] = legacyProps.model.value
    converted[compatModelEventPrefix + event] = legacyProps.model.callback
  }

  return converted
}

function convertLegacyEventKey(event: string): string {
  // normalize v2 event prefixes