對於表單大家都很熟悉,v-model 大家也很喜歡,他確實很方便。那麼他是怎麼實現的呢, 其實他是一個語法糖, v-model 幹了 兩件事 下面以 input 爲例
<input type="text" v-bind:value='message' @input='message = $event.target.value'>
等價於
<input type="text" v-model='message'>
對於自定義組件,我們也要實現雙向綁定,對於可編輯div大家都瞭解,接下來我們來實現可編輯div的雙向綁定
子組件:ContentEditable
<template>
<div
class="edit-div"
v-html="innerText"
:contenteditable="canEdit"
@focus="isLocked = true"
@blur="isLocked = false"
@input="changeText"
placeholder="請輸入審批意見(必填)"
></div>
</template>
<script>
export default {
name: "ContentEditable",
props: {
value: {
type: String,
default: ""
},
canEdit: {
type: Boolean,
default: true
}
},
data() {
return {
innerText: this.value,
isLocked: false
};
},
watch: {
value() {
if (!this.isLocked || !this.innerText) {
this.innerText = this.value;
}
}
},
methods: {
changeText() {
this.$emit("input", this.$el.innerHTML);
}
}
};
</script>
<style lang="scss">
.edit-div {
width: 100%;
height: 100%;
overflow: auto;
word-break: break-all;
outline: none;
user-select: text;
white-space: pre-wrap;
text-align: left;
&[contenteditable="true"] {
&:empty:before {
content: attr(placeholder);
display: block;
color: #ccc;
}
}
}
</style>
調用:
<ContentEditable v-model="text" />