基于elementUI使用v-model实现经纬度输入的vue组件

<template>
 <div class="coordinates">
  <!-- 经度 -->
  <div class="item">
   <span class="itude"
      @click="itudeChange(true)">{{ longFlag | longitudeName }}</span>
   <el-input v-model.number="longitude[0]"
        @change="change(true,0)"
        size="mini">
    <i slot="suffix">°</i>
   </el-input>
   <el-input v-model.number="longitude[1]"
        @change="change(true,1)"
        size="mini">
    <i slot="suffix">′</i>
   </el-input>
   <el-input v-model.number="longitude[2]"
        @change="change(true,2)"
        size="mini">
    <i slot="suffix">″</i>
   </el-input>
  </div>
  <!-- 纬度 -->
  <div class="item">
   <span class="itude"
      @click="itudeChange(false)">{{ latFlag | latitudeName }}</span>
   <el-input v-model.number="latitude[0]"
        @change="change(false,0)"
        size="mini">
    <i slot="suffix">°</i>
   </el-input>
   <el-input v-model.number="latitude[1]"
        @change="change(false,1)"
        size="mini">
    <i slot="suffix">′</i>
   </el-input>
   <el-input v-model.number="latitude[2]"
        @change="change(false,2)"
        size="mini">
    <i slot="suffix">″</i>
   </el-input>
  </div>
 </div>
</template>

value: { //绑定的 value
 type: Array,
 require: true,
 validator: function (value) {
  let len = value.length > 0 && value.length === 2
  let isvalid = Math.abs(value[0]) < 180 && Math.abs(value[1]) < 90
  return len && isvalid
 },
 default: function () {
  return []
 }
}

model: { 
 prop: 'value',
 event: 'input'
},

/**
 * v-model 绑定事件 双向绑定实现
 */
returnBackFn () {
 let longitude = parseFloat(this.longFlag + this.Dms2D(this.longitude));
 let latitude = parseFloat(this.latFlag + this.Dms2D(this.latitude));
 let array = [longitude, latitude]
 this.$emit('input', array);
},

<template>
 <div class="coordinates">
  <!-- 经度 -->
  <div class="item">
   <span class="itude"
      @click="itudeChange(true)">{{ longFlag | longitudeName }}</span>
   <el-input v-model.number="longitude[0]"
        @change="change(true,0)"
        size="mini">
    <i slot="suffix">°</i>
   </el-input>
   <el-input v-model.number="longitude[1]"
        @change="change(true,1)"
        size="mini">
    <i slot="suffix">′</i>
   </el-input>
   <el-input v-model.number="longitude[2]"
        @change="change(true,2)"
        size="mini">
    <i slot="suffix">″</i>
   </el-input>
  </div>
  <!-- 纬度 -->
  <div class="item">
   <span class="itude"
      @click="itudeChange(false)">{{ latFlag | latitudeName }}</span>
   <el-input v-model.number="latitude[0]"
        @change="change(false,0)"
        size="mini">
    <i slot="suffix">°</i>
   </el-input>
   <el-input v-model.number="latitude[1]"
        @change="change(false,1)"
        size="mini">
    <i slot="suffix">′</i>
   </el-input>
   <el-input v-model.number="latitude[2]"
        @change="change(false,2)"
        size="mini">
    <i slot="suffix">″</i>
   </el-input>
  </div>
 </div>
</template>
<script>
require('math')
export default {
 name: 'Coordinates',
 props: {
  value: { //绑定的 value
   type: Array,
   require: true,
   validator: function (value) {
    let len = value.length > 0 && value.length === 2
    let isvalid = Math.abs(value[0]) < 180 && Math.abs(value[1]) < 90
    return len && isvalid
   },
   default: function () {
    return []
   }
  }
 },
 // model: { // prop为 value 时不用实现 model 但是this.$emit(event,arg) 传入的event需要为 'input'
 //  prop: 'value',
 //  event: 'returnBack'
 // },
 data () {
  return {
   longitude: [], // 经度
   latitude: [],  // 纬度
   longFlag: '+', //表示东经西经
   latFlag: '+',  //表示南纬北纬
  }
 },
 created: function () {
  this.initData();
 },
 filters: {
  longitudeName (value) {
   return value === '+' ? "东经" : "西经"
  },
  latitudeName (value) {
   return value === '+' ? "南纬" : "北纬"
  }
 },
 watch: {
  /**
  * 监测父组件绑定的value
  */
  value () {
   this.initData();
  }
 },
 computed: {
  // 转换为  东经 XXX°XX′XX″  格式 
  // 返回一个经纬度的数组
  formatString () {
   let longitude = (this.longFlag === '+' ? "东经 " : "西经 ") + this.longitude[0] + '°' + this.longitude[1] + '′' + this.longitude[2] + '″';
   let latitude = (this.latFlag === '+' ? "南纬 " : "北纬 ") + this.latitude[0] + '°' + this.latitude[1] + '′' + this.latitude[2] + '″';
   return [longitude, latitude]
  }
 },
 methods: {
  /**
   * 东经西经，南纬北纬 change事件
   */
  itudeChange (flag) {
   flag ? (this.longFlag = (this.longFlag === '+' ? '-' : '+')) : (this.latFlag = (this.latFlag === '+' ? '-' : '+'))
   this.returnBackFn()
  },
  /**
   * 初始化数据，父组件修改绑定的value时调用
   */
  initData () {
   this.longitude = this.D2Dms(Math.abs(this.value[0]));
   this.latitude = this.D2Dms(Math.abs(this.value[1]));
   this.longFlag = this.value[0] < 0 ? '-' : '+'
   this.latFlag = this.value[1] < 0 ? '-' : '+'
  },
  /**
   * 输入框change事件，数据合法性验证
   */
  change (flag, index) {
   let name = '', max = 0
   flag ? [name, max] = ['longitude', 179] : [name, max] = ['latitude', 89]
   index ? max = 59 : null
   let value = parseInt(this[name][index], 10)
   if (isNaN(value)) {
    value = 0;
   }
   value = value < 0 ? 0 : value
   value = value > max ? max : value
   this.$set(this[name], index, value)
   this.returnBackFn()
  },
  /**
   * v-model 绑定事件 双向绑定实现
   */
  returnBackFn () {
   let longitude = parseFloat(this.longFlag + this.Dms2D(this.longitude));
   let latitude = parseFloat(this.latFlag + this.Dms2D(this.latitude));
   let array = [longitude, latitude]
   this.$emit('input', array);
  },
  /**
  * 度转度分秒
  */
  D2Dms (d_data = 0) {
   var degree = parseInt(d_data);
   var min = parseInt((d_data - degree) * 60);
   var sec = parseInt((d_data - degree) * 3600 - min * 60);
   return [degree, min, sec];
  },
  /**
  * 度分秒转度
  */
  Dms2D (dms_data = [0, 0, 0]) {
   let d = parseFloat(dms_data[0]);
   let m = parseFloat(dms_data[1]);
   let s = parseFloat(dms_data[2]);
   return this.keepFourDecimal(d + m / 60 + s / 60 / 60);
  },
  /**
  * 保留四位小数，小于四位精度可能丢失
  */
  keepFourDecimal (num) {
   var result = parseFloat(num);
   if (isNaN(result)) {
    return 0;
   }
   result = Math.round(num * 10000) / 10000;
   return result;
  }
 },
}
</script>
<style lang="less" scoped>
@color-border: #9e9e9e;
@height: 28px;
.coordinates {
 border: 1px solid @color-border;
 width: fit-content;
 display: inline-flex;
}
.item:nth-of-type(1) {
 border-right: 1px solid @color-border;
}
.el-input {
 width: 40px;
}
.itude {
 height: @height;
 line-height: @height;
 display: inline-block;
 padding-left: 5px;
 cursor: pointer;
 user-select: none;
}
i {
 font-size: 18px;
 color: gray;
}
</style>
<style lang="less">
.el-input__inner {
 text-align: center;
 border: none;
 border-radius: unset;
}
.el-input--suffix .el-input__inner {
 padding: 0;
}
</style>

<template>
 <div id="example">
  <Coordinates ref="coordinates"
         v-model="value"></Coordinates>
  <el-button @click="changeValue"
        type="primary">
   change value
  </el-button>
  <br>
  <span>value：{{value.toString()}}</span>
  <br>
  <span>度分秒格式：{{formatString.toString()}}</span>
  <el-button @click="refresh"
        type="primary">
   refresh
  </el-button>
 </div>
</template>
<script>
import Coordinates from '@/components/Coordinates'
export default {
 name: 'index',
 components: {
  Coordinates
 },
 data () {
  return {
   value: [12.34, -45.67],
   formatString: []
  }
 },
 mounted () {
  this.refresh ()
 },
 methods: {
  changeValue () {
   this.$set(this.value, 0, (this.value[0] + 2) >= 180 ? 0 : (this.value[0] + 2))
   this.$set(this.value, 1, (this.value[1] + 2) >= 90 ? 0 : (this.value[1] + 2))
   setTimeout(() => {
    refresh ()
   }, 10);
  },
  refresh () {
   // 获取度分秒格式
   this.formatString = this.$refs.coordinates.formatString
  }
 }
}
</script>
<style lang="less" scoped>
#example {
 padding: 20px;
}
.el-button {
 margin: 20px;
}
span {
 font-size: 17px;
}
</style>