el-button源码解读4——props color和native-type

js 复制代码

  <component
    :is="tag"
    ref="_ref"
    v-bind="_props"
    :class="buttonKls"
    :style="buttonStyle"
    @click="handleClick"
  >

:style="buttonStyle"：用于在设置了 color 时，自动计算并应用按钮各状态（默认、悬停、激活、禁用）的颜色样式，无需手动设置每个状态的颜色。

js 复制代码

const buttonStyle = useButtonCustomStyle(props)
/**
 * 获取实例中props为name的值
 */
export const useProp = <T>(name: string): ComputedRef<T | undefined> => {
  const vm = getCurrentInstance()
  return computed(() => (vm?.proxy?.$props as any)?.[name])
}


/**
 * 获取表单的disabled状态
 * @param fallback 默认值
 * @returns 表单的disabled状态
 */
export const useFormDisabled = (fallback?: MaybeRef<boolean | undefined>) => {
  const disabled = useProp<boolean>('disabled')
  const form = inject(formContextKey, undefined)
  // 如果是表单内部的button那么是有值的，如果是外部的button那么是undefined
  console.log('form', form)
  /**
   * 组件自身的 disabled prop 
      ↓ (如果没有)
      传入的 fallback 参数
      ↓ (如果没有)
      表单的 disabled 状态
      ↓ (如果没有)
      默认值 false
   */
  return computed(
    () => disabled.value || unref(fallback) || form?.disabled || false
  )
}

/**
 * 获取按钮自定义样式
 * @param props 
 * @returns 
 */
export function useButtonCustomStyle(props: ButtonProps) {
  // 获取按钮的disabled状态
  const _disabled = useFormDisabled()
  // 获取按钮的命名空间
  const ns = useNamespace('button')

  // calculate hover & active color by custom color
  // only work when custom color
  return computed(() => {
    let styles: Record<string, string> = {}

    let buttonColor = props.color

    if (buttonColor) {
      // 检测buttonColor是否为CSS变量格式 ，并提取变量名 如 var(--el-color-primary)
      const match = (buttonColor as string).match(/var\((.*?)\)/)
      if (match) {
        buttonColor = window
          .getComputedStyle(window.document.documentElement)
          .getPropertyValue(match[1])
      }
      // TinyColor: Fast, small color manipulation and conversion for JavaScript
      const color = new TinyColor(buttonColor)
      console.log('color', color)
      // tint - 变亮（添加白色）变亮20%
      // darken - 变暗（添加黑色）变暗20%
      const activeBgColor = props.dark
        ? color.tint(20).toString()
        : darken(color, 20)

      if (props.plain) {
        styles = ns.cssVarBlock({
          'bg-color': props.dark
            ? darken(color, 90)
            : color.tint(90).toString(),
          'text-color': buttonColor,
          'border-color': props.dark
            ? darken(color, 50)
            : color.tint(50).toString(),
          'hover-text-color': `var(${ns.cssVarName('color-white')})`,
          'hover-bg-color': buttonColor,
          'hover-border-color': buttonColor,
          'active-bg-color': activeBgColor,
          'active-text-color': `var(${ns.cssVarName('color-white')})`,
          'active-border-color': activeBgColor,
        })

        if (_disabled.value) {
          styles[ns.cssVarBlockName('disabled-bg-color')] = props.dark
            ? darken(color, 90)
            : color.tint(90).toString()
          styles[ns.cssVarBlockName('disabled-text-color')] = props.dark
            ? darken(color, 50)
            : color.tint(50).toString()
          styles[ns.cssVarBlockName('disabled-border-color')] = props.dark
            ? darken(color, 80)
            : color.tint(80).toString()
        }
      } else {
        const hoverBgColor = props.dark
          ? darken(color, 30)
          : color.tint(30).toString()
        const textColor = color.isDark()
          ? `var(${ns.cssVarName('color-white')})`
          : `var(${ns.cssVarName('color-black')})`
        styles = ns.cssVarBlock({
          'bg-color': buttonColor,
          'text-color': textColor,
          'border-color': buttonColor,
          'hover-bg-color': hoverBgColor,
          'hover-text-color': textColor,
          'hover-border-color': hoverBgColor,
          'active-bg-color': activeBgColor,
          'active-border-color': activeBgColor,
        })

        if (_disabled.value) {
          const disabledButtonColor = props.dark
            ? darken(color, 50)
            : color.tint(50).toString()
          styles[ns.cssVarBlockName('disabled-bg-color')] = disabledButtonColor
          styles[ns.cssVarBlockName('disabled-text-color')] = props.dark
            ? 'rgba(255, 255, 255, 0.5)'
            : `var(${ns.cssVarName('color-white')})`
          styles[ns.cssVarBlockName('disabled-border-color')] =
            disabledButtonColor
        }
      }
    }

    return styles
  })
}

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js 复制代码

props：native-type
export const buttonNativeTypes = ['button', 'submit', 'reset'] as const

props:
  /**
   * @description native button type
   */
  nativeType: {
    type: String,
    values: buttonNativeTypes,
    default: 'button',
  },