core/packages/runtime-dom/src/modules/props.ts

// __UNSAFE__
// Reason: potentially setting innerHTML.
// This can come from explicit usage of v-html or innerHTML as a prop in render

import { warn, DeprecationTypes, compatUtils } from '@vue/runtime-core'
import { includeBooleanAttr } from '@vue/shared'

// functions. The user is responsible for using them with only trusted content.
export function patchDOMProp(
  el: any,
  key: string,
  value: any,
  // the following args are passed only due to potential innerHTML/textContent
  // overriding existing VNodes, in which case the old tree must be properly
  // unmounted.
  prevChildren: any,
  parentComponent: any,
  parentSuspense: any,
  unmountChildren: any
) {
  if (key === 'innerHTML' || key === 'textContent') {
    if (prevChildren) {
      unmountChildren(prevChildren, parentComponent, parentSuspense)
    }
    el[key] = value == null ? '' : value
    return
  }

  if (key === 'value' && el.tagName !== 'PROGRESS') {
    // store value as _value as well since
    // non-string values will be stringified.
    el._value = value
    const newValue = value == null ? '' : value
    if (el.value !== newValue) {
      el.value = newValue
    }
    if (value == null) {
      el.removeAttribute(key)
    }
    return
  }

  if (value === '' || value == null) {
    const type = typeof el[key]
    if (type === 'boolean') {
      // e.g. <select multiple> compiles to { multiple: '' }
      el[key] = includeBooleanAttr(value)
      return
    } else if (value == null && type === 'string') {
      // e.g. <div :id="null">
      el[key] = ''
      el.removeAttribute(key)
      return
    } else if (type === 'number') {
      // e.g. <img :width="null">
      // the value of some IDL attr must be greater than 0, e.g. input.size = 0 -> error
      try {
        el[key] = 0
      } catch {}
      el.removeAttribute(key)
      return
    }
  }

  if (
    __COMPAT__ &&
    value === false &&
    compatUtils.isCompatEnabled(
      DeprecationTypes.ATTR_FALSE_VALUE,
      parentComponent
    )
  ) {
    const type = typeof el[key]
    if (type === 'string' || type === 'number') {
      __DEV__ &&
        compatUtils.warnDeprecation(
          DeprecationTypes.ATTR_FALSE_VALUE,
          parentComponent,
          key
        )
      el[key] = type === 'number' ? 0 : ''
      el.removeAttribute(key)
      return
    }
  }

  // some properties perform value validation and throw
  try {
    el[key] = value
  } catch (e: any) {
    if (__DEV__) {
      warn(
        `Failed setting prop "${key}" on <${el.tagName.toLowerCase()}>: ` +
          `value ${value} is invalid.`,
        e
      )
    }
  }
}