從0搭建vue3組件庫Input組件

更新時(shí)間：2022年11月11日 14:11:03 作者：迪迪滴

這篇文章主要介紹了從0搭建vue3組件庫Input組件,每個(gè)功能的實(shí)現(xiàn)代碼都做了精簡(jiǎn),方便大家快速定位到核心邏輯,接下來就開始對(duì)這些功能進(jìn)行實(shí)例代碼講解，需要的朋友可以參考下

基礎(chǔ)用法

首先先新建一個(gè)input.vue文件,然后寫入一個(gè)最基本的input輸入框

<template>
  <div class="k-input">
    <input class="k-input__inner" />
  </div>
</template>

然后在我們的 vue 項(xiàng)目examples下的app.vue引入Input組件

<template>
  <div class="Shake-demo">
    <Input />
  </div>
</template>
<script lang="ts" setup>
import { Input } from "kitty-ui";
</script>

此時(shí)頁面上便出現(xiàn)了原生的輸入框,所以需要對(duì)這個(gè)輸入框進(jìn)行樣式的添加,在input.vue同級(jí)新建style/index.less,Input樣式便寫在這里

.k-input {
  font-size: 14px;
  display: inline-block;
  position: relative;

  .k-input__inner {
    background-color: #fff;
    border-radius: 4px;
    border: 1px solid #dcdfe6;
    box-sizing: border-box;
    color: #606266;
    display: inline-block;
    font-size: inherit;
    height: 40px;
    line-height: 40px;
    outline: none;
    padding: 0 15px;
    width: 100%;
    &::placeholder {
      color: #c2c2ca;
    }

    &:hover {
      border: 1px solid #c0c4cc;
    }

    &:focus {
      border: 1px solid #409eff;
    }
  }
}

接下來要實(shí)現(xiàn)Input組件的核心功能:雙向數(shù)據(jù)綁定。當(dāng)我們?cè)?vue 中使用input輸入框的時(shí)候,我們可以直接使用v-model來實(shí)現(xiàn)雙向數(shù)據(jù)綁定,v-model其實(shí)就是value @input結(jié)合的語法糖。而在 vue3 組件中使用v-model則表示的是modelValue @update:modelValue的語法糖。比如Input組件為例

<Input v-model="tel" />

其實(shí)就是

<Input :modelValue="tel" @update:modelValue="tel = $event" />

所以在input.vue中我們就可以根據(jù)這個(gè)來實(shí)現(xiàn)Input組件的雙向數(shù)據(jù)綁定,這里我們使用setup語法

<template>
  <div class="k-input">
    <input
      class="k-input__inner"
      :value="inputProps.modelValue"
      @input="changeInputVal"
    />
  </div>
</template>
<script lang="ts" setup>
//組件命名
defineOptions({
  name: "k-input",
});
//組件接收的值類型
type InputProps = {
  modelValue?: string | number;
};

//組件發(fā)送事件類型
type InputEmits = {
  (e: "update:modelValue", value: string): void;
};

//withDefaults可以為props添加默認(rèn)值等
const inputProps = withDefaults(defineProps<InputProps>(), {
  modelValue: "",
});
const inputEmits = defineEmits<InputEmits>();

const changeInputVal = (event: Event) => {
  inputEmits("update:modelValue", (event.target as HTMLInputElement).value);
};
</script>

到這里基礎(chǔ)用法就完成了,接下來開始實(shí)現(xiàn)禁用狀態(tài)

禁用狀態(tài)

這個(gè)比較簡(jiǎn)單,只要根據(jù)props的disabled來賦予禁用類名即可

<template>
  <div class="k-input" :class="styleClass">
    <input
      class="k-input__inner"
      :value="inputProps.modelValue"
      @input="changeInputVal"
      :disabled="inputProps.disabled"
    />
  </div>
</template>
<script lang="ts" setup>
//...
type InputProps = {
  modelValue?: string | number;
  disabled?: boolean;
};
//...

//根據(jù)props更改類名
const styleClass = computed(() => {
  return {
    "is-disabled": inputProps.disabled,
  };
});
</script>

然后給is-disabled寫些樣式

//...

.k-input.is-disabled {
  .k-input__inner {
    background-color: #f5f7fa;
    border-color: #e4e7ed;
    color: #c0c4cc;
    cursor: not-allowed;
    &::placeholder {
      color: #c3c4cc;
    }
  }
}

尺寸

按鈕尺寸包括medium,small,mini,不傳則是默認(rèn)尺寸。同樣的根據(jù)props的size來賦予不同類名

const styleClass = computed(() => {
  return {
    "is-disabled": inputProps.disabled,
    [`k-input--${inputProps.size}`]: inputProps.size,
  };
});

然后寫這三個(gè)類名的不同樣式

//...
.k-input.k-input--medium {
  .k-input__inner {
    height: 36px;
    &::placeholder {
      font-size: 15px;
    }
  }
}

.k-input.k-input--small {
  .k-input__inner {
    height: 32px;

    &::placeholder {
      font-size: 14px;
    }
  }
}

.k-input.k-input--mini {
  .k-input__inner {
    height: 28px;

    &::placeholder {
      font-size: 13px;
    }
  }
}

繼承原生 input 屬性

原生的input有type,placeholder等屬性,這里可以使用 vue3 中的useAttrs來實(shí)現(xiàn)props穿透.子組件可以通過v-bind將props綁定

<template>
  <div class="k-input" :class="styleClass">
    <input
      class="k-input__inner"
      :value="inputProps.modelValue"
      @input="changeInputVal"
      :disabled="inputProps.disabled"
      v-bind="attrs"
    />
  </div>
</template>
<script lang="ts" setup>
//...

const attrs = useAttrs();
</script>

可清空

通過clearable屬性、Input的值是否為空以及是否鼠標(biāo)是否移入來判斷是否需要顯示可清空?qǐng)D標(biāo)。圖標(biāo)則使用組件庫的Icon組件

<template>
  <div
    class="k-input"
    @mouseenter="isEnter = true"
    @mouseleave="isEnter = false"
    :class="styleClass"
  >
    <input
      class="k-input__inner"
      :disabled="inputProps.disabled"
      v-bind="attrs"
      :value="inputProps.modelValue"
      @input="changeInputVal"
    />
    <div
      @click="clearValue"
      v-if="inputProps.clearable && isClearAbled"
      v-show="isFoucs"
      class="k-input__suffix"
    >
      <Icon name="error" />
    </div>
  </div>
</template>
<script setup lang="ts">
//...
import Icon from "../icon/index";
//...
//雙向數(shù)據(jù)綁定&接收屬性
type InputProps = {
  modelValue?: string | number;
  disabled?: boolean;
  size?: string;
  clearable?: boolean;
};
//...
const isClearAbled = ref(false);
const changeInputVal = (event: Event) => {
  //可清除clearable
  (event.target as HTMLInputElement).value
    ? (isClearAbled.value = true)
    : (isClearAbled.value = false);

  inputEmits("update:modelValue", (event.target as HTMLInputElement).value);
};

//清除input value
const isEnter = ref(true);
const clearValue = () => {
  inputEmits("update:modelValue", "");
};
</script>

清除圖標(biāo)部分 css 樣式

.k-input__suffix {
  position: absolute;
  right: 10px;
  height: 100%;
  top: 0;
  display: flex;
  align-items: center;
  cursor: pointer;
  color: #c0c4cc;
}

密碼框 show-password

通過傳入show-password屬性可以得到一個(gè)可切換顯示隱藏的密碼框。這里要注意的是如果傳了clearable則不會(huì)顯示切換顯示隱藏的圖標(biāo)

<template>
  <div
    class="k-input"
    @mouseenter="isEnter = true"
    @mouseleave="isEnter = false"
    :class="styleClass"
  >
    <input
      ref="ipt"
      class="k-input__inner"
      :disabled="inputProps.disabled"
      v-bind="attrs"
      :value="inputProps.modelValue"
      @input="changeInputVal"
    />
    <div class="k-input__suffix" v-show="isShowEye">
      <Icon @click="changeType" :name="eyeIcon" />
    </div>
  </div>
</template>
<script setup lang="ts">
//...
const attrs = useAttrs();

//...

//顯示隱藏密碼框 showPassword
const ipt = ref();
Promise.resolve().then(() => {
  if (inputProps.showPassword) {
    ipt.value.type = "password";
  }
});
const eyeIcon = ref("browse");
const isShowEye = computed(() => {
  return (
    inputProps.showPassword && inputProps.modelValue && !inputProps.clearable
  );
});
const changeType = () => {
  if (ipt.value.type === "password") {
    eyeIcon.value = "eye-close";
    ipt.value.type = attrs.type || "text";
    return;
  }
  ipt.value.type = "password";
  eyeIcon.value = "browse";
};
</script>

這里是通過獲取input元素,然后通過它的type屬性進(jìn)行切換,其中browse和eye-close分別是Icon組件中眼睛開與閉,效果如下

帶 Icon 的輸入框

通過prefix-icon和suffix-icon 屬性可以為Input組件添加首尾圖標(biāo)。

可以通過計(jì)算屬性判斷出是否顯示首尾圖標(biāo),防止和前面的clearable和show-password沖突.這里代碼做了

<template>
  <div class="k-input">
    <input
      ref="ipt"
      class="k-input__inner"
      :class="{ ['k-input--prefix']: isShowPrefixIcon }"
      :disabled="inputProps.disabled"
      v-bind="attrs"
      :value="inputProps.modelValue"
      @input="changeInputVal"
    />

    <div class="k-input__prefix" v-if="isShowPrefixIcon">
      <Icon :name="inputProps.prefixIcon" />
    </div>
    <div class="k-input__suffix no-cursor" v-if="isShowSuffixIcon">
      <Icon :name="inputProps.suffixIcon" />
    </div>
  </div>
</template>
<script setup lang="ts">
//...
type InputProps = {
  prefixIcon?: string;
  suffixIcon?: string;
};

//...

//帶Icon輸入框
const isShowSuffixIcon = computed(() => {
  return (
    inputProps.suffixIcon && !inputProps.clearable && !inputProps.showPassword
  );
});
const isShowPrefixIcon = computed(() => {
  return inputProps.prefixIcon;
});
</script>

相關(guān)樣式部分

.k-input__suffix,
.k-input__prefix {
  position: absolute;
  right: 10px;
  height: 100%;
  top: 0;
  display: flex;
  align-items: center;
  cursor: pointer;
  color: #c0c4cc;
  font-size: 15px;
}

.no-cursor {
  cursor: default;
}

.k-input--prefix.k-input__inner {
  padding-left: 30px;
}

.k-input__prefix {
  position: absolute;
  width: 20px;
  cursor: default;
  left: 10px;
}

在app.vue中使用效果如下

<template>
  <div class="input-demo">
    <Input v-model="tel" suffixIcon="edit" placeholder="請(qǐng)輸入內(nèi)容" />

    <Input v-model="tel" prefixIcon="edit" placeholder="請(qǐng)輸入內(nèi)容" />
  </div>
</template>
<script lang="ts" setup>
import { Input } from "kitty-ui";
import { ref } from "vue";
const tel = ref("");
</script>
<style lang="less">
.input-demo {
  width: 200px;
}
</style>

文本域

將type屬性的值指定為textarea即可展示文本域模式。它綁定的事件以及屬性和input基本一樣

<template>
  <div class="k-textarea" v-if="attrs.type === 'textarea'">
    <textarea
      class="k-textarea__inner"
      :style="textareaStyle"
      v-bind="attrs"
      ref="textarea"
      :value="inputProps.modelValue"
      @input="changeInputVal"
    />
  </div>
  <div
    v-else
    class="k-input"
    @mouseenter="isEnter = true"
    @mouseleave="isEnter = false"
    :class="styleClass"
  >
    ...
  </div>
</template>

樣式基本也就是focus,hover改變 border 顏色

.k-textarea {
  width: 100%;

  .k-textarea__inner {
    display: block;
    padding: 5px 15px;
    line-height: 1.5;
    box-sizing: border-box;
    width: 100%;
    font-size: inherit;
    color: #606266;
    background-color: #fff;
    background-image: none;
    border: 1px solid #dcdfe6;
    border-radius: 4px;

    &::placeholder {
      color: #c2c2ca;
    }

    &:hover {
      border: 1px solid #c0c4cc;
    }

    &:focus {
      outline: none;
      border: 1px solid #409eff;
    }
  }
}

可自適應(yīng)高度文本域

組件可以通過接收autosize屬性來開啟自適應(yīng)高度,同時(shí)autosize也可以傳對(duì)象形式來指定最小和最大行高

type AutosizeObj = {
    minRows?: number
    maxRows?: number
}
type InputProps = {
    autosize?: boolean | AutosizeObj
}

具體實(shí)現(xiàn)原理是通過監(jiān)聽輸入框值的變化來調(diào)整textarea的樣式,其中用到了一些原生的方法譬如window.getComputedStyle(獲取原生css對(duì)象),getPropertyValue(獲取css屬性值)等,所以原生js忘記的可以復(fù)習(xí)一下

...
const textareaStyle = ref<any>()
const textarea = shallowRef<HTMLTextAreaElement>()
watch(() => inputProps.modelValue, () => {
    if (attrs.type === 'textarea' && inputProps.autosize) {
        const minRows = isObject(inputProps.autosize) ? (inputProps.autosize as AutosizeObj).minRows : undefined
        const maxRows = isObject(inputProps.autosize) ? (inputProps.autosize as AutosizeObj).maxRows : undefined
        nextTick(() => {
            textareaStyle.value = calcTextareaHeight(textarea.value!, minRows, maxRows)
        })
    }

}, { immediate: true })

其中calcTextareaHeight為

const isNumber = (val: any): boolean => {
    return typeof val === 'number'
}
//隱藏的元素
let hiddenTextarea: HTMLTextAreaElement | undefined = undefined

//隱藏元素樣式
const HIDDEN_STYLE = `
  height:0 !important;
  visibility:hidden !important;
  overflow:hidden !important;
  position:absolute !important;
  z-index:-1000 !important;
  top:0 !important;
  right:0 !important;
`

const CONTEXT_STYLE = [
    'letter-spacing',
    'line-height',
    'padding-top',
    'padding-bottom',
    'font-family',
    'font-weight',
    'font-size',
    'text-rendering',
    'text-transform',
    'width',
    'text-indent',
    'padding-left',
    'padding-right',
    'border-width',
    'box-sizing',
]

type NodeStyle = {
    contextStyle: string
    boxSizing: string
    paddingSize: number
    borderSize: number
}

type TextAreaHeight = {
    height: string
    minHeight?: string
}

function calculateNodeStyling(targetElement: Element): NodeStyle {
  //獲取實(shí)際textarea樣式返回并賦值給隱藏的textarea
    const style = window.getComputedStyle(targetElement)

    const boxSizing = style.getPropertyValue('box-sizing')

    const paddingSize =
        Number.parseFloat(style.getPropertyValue('padding-bottom')) +
        Number.parseFloat(style.getPropertyValue('padding-top'))

    const borderSize =
        Number.parseFloat(style.getPropertyValue('border-bottom-width')) +
        Number.parseFloat(style.getPropertyValue('border-top-width'))

    const contextStyle = CONTEXT_STYLE.map(
        (name) => `${name}:${style.getPropertyValue(name)}`
    ).join(';')

    return { contextStyle, paddingSize, borderSize, boxSizing }
}

export function calcTextareaHeight(
    targetElement: HTMLTextAreaElement,
    minRows = 1,
    maxRows?: number
): TextAreaHeight {
    if (!hiddenTextarea) {
      //創(chuàng)建隱藏的textarea
        hiddenTextarea = document.createElement('textarea')
        document.body.appendChild(hiddenTextarea)
    }
    //給隱藏的teatarea賦予實(shí)際textarea的樣式以及值(value)
    const { paddingSize, borderSize, boxSizing, contextStyle } =
        calculateNodeStyling(targetElement)
    hiddenTextarea.setAttribute('style', `${contextStyle};${HIDDEN_STYLE}`)
    hiddenTextarea.value = targetElement.value || targetElement.placeholder || ''
    //隱藏textarea整個(gè)高度,包括內(nèi)邊距padding,border
    let height = hiddenTextarea.scrollHeight
    const result = {} as TextAreaHeight
    //判斷boxSizing,返回實(shí)際高度
    if (boxSizing === 'border-box') {
        height = height + borderSize
    } else if (boxSizing === 'content-box') {
        height = height - paddingSize
    }

    hiddenTextarea.value = ''
    //計(jì)算單行高度
    const singleRowHeight = hiddenTextarea.scrollHeight - paddingSize

    if (isNumber(minRows)) {
        let minHeight = singleRowHeight * minRows
        if (boxSizing === 'border-box') {
            minHeight = minHeight + paddingSize + borderSize
        }
        height = Math.max(minHeight, height)
        result.minHeight = `${minHeight}px`
    }
    if (isNumber(maxRows)) {
        let maxHeight = singleRowHeight * maxRows!
        if (boxSizing === 'border-box') {
            maxHeight = maxHeight + paddingSize + borderSize
        }
        height = Math.min(maxHeight, height)
    }
    result.height = `${height}px`
    hiddenTextarea.parentNode?.removeChild(hiddenTextarea)
    hiddenTextarea = undefined

    return result
}

這里的邏輯稍微復(fù)雜一點(diǎn),大致就是創(chuàng)建一個(gè)隱藏的textarea,然后每次當(dāng)輸入框值發(fā)生變化時(shí),將它的value賦值為組件的textarea的value,最后計(jì)算出這個(gè)隱藏的textarea的scrollHeight以及其它padding之類的值并作為高度返回賦值給組件中的textarea

最后在app.vue中使用

<template>
  <div class="input-demo">
    <Input
      v-model="tel"
      :autosize="{ minRows: 2 }"
      type="textarea"
      suffixIcon="edit"
      placeholder="請(qǐng)輸入內(nèi)容"
    />
  </div>
</template>

復(fù)合型輸入框

我們可以使用復(fù)合型輸入框來前置或者后置我們的元素,如下所示

這里我們借助 vue3 中的slot進(jìn)行實(shí)現(xiàn),其中用到了useSlots來判斷用戶使用了哪個(gè)插槽,從而展示不同樣式

import { useSlots } from "vue";

//復(fù)合輸入框
const slots = useSlots();

同時(shí)template中接收前后兩個(gè)插槽

<template>
  <div
    class="k-input"
    @mouseenter="isEnter = true"
    @mouseleave="isEnter = false"
    :class="styleClass"
  >
    <div class="k-input__prepend" v-if="slots.prepend">
      <slot name="prepend"></slot>
    </div>
    <input
      ref="ipt"
      class="k-input__inner"
      :class="inputStyle"
      :disabled="inputProps.disabled"
      v-bind="attrs"
      :value="inputProps.modelValue"
      @input="changeInputVal"
    />
    <div class="k-input__append" v-if="slots.append">
      <slot name="append"></slot>
    </div>
  </div>
</template>
<script setup lang="ts">
import { useSlots } from "vue";
const styleClass = computed(() => {
  return {
    ["k-input-group k-input-prepend"]: slots.prepend,
    ["k-input-group k-input-append"]: slots.append,
  };
});
//復(fù)合輸入框
const slots = useSlots();
</script>

最后給兩個(gè)插槽寫上樣式就實(shí)現(xiàn)了復(fù)合型輸入框啦

.k-input.k-input-group.k-input-append,
.k-input.k-input-group.k-input-prepend {
  line-height: normal;
  display: inline-table;
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;

  .k-input__inner {
    border-radius: 0 4px 4px 0;
  }

  //復(fù)合輸入框
  .k-input__prepend,
  .k-input__append {
    background-color: #f5f7fa;
    color: #909399;
    vertical-align: middle;
    display: table-cell;
    position: relative;
    border: 1px solid #dcdfe6;
    border-radius: 4 0px 0px 4px;
    padding: 0 20px;
    width: 1px;
    white-space: nowrap;
  }

  .k-input__append {
    border-radius: 0 4px 4px 0px;
  }
}

.k-input.k-input-group.k-input-append {
  .k-input__inner {
    border-top-right-radius: 0px;
    border-bottom-right-radius: 0px;
  }
}

在app.vue中使用

<template>
    <div class="input-demo">
        <Input v-model="tel" placeholder="請(qǐng)輸入內(nèi)容">
        <template #prepend>
            http://
        </template>
        </Input>
        <Input v-model="tel" placeholder="請(qǐng)輸入內(nèi)容">
        <template #append>
            .com
        </template>
        </Input>
    </div>
</template>