在 Vuejs 中更改 v-model 输入值时动态数据不会更新

Question

我正在使用这个 Weather API 构建一个天气应用程序。我正在尝试添加一个 <input> 字段值，当它更改城市名称时，然后更新其他值预测。

我创建了 <input> 更新城市值的字段，它应该相应地更新天气预报。我知道 v-model 正在工作，但它不会更改数据结果。只有当我在 Vue-instance 中硬编码不同的城市时，数据才会更新更改。

 <template>
  <div class="home">
    <h1>{{ msg }}</h1>
    <p>A weather app built Vuejs & Open Weather App. Made by Manuel Abascal</p>
    <input type="text" v-model.lazy="currentWeather.name">
    <div class="forecast">
     <div v-if="this.currentWeather">
      <!-- Forecast stat values -->
      <h2>Right now:</h2>
      <div><strong>City:</strong> {{ currentCity }}</div>
      <div><strong>Longitude: </strong> {{ currentWeather.coord.lon }}</div>
      <div><strong>Latitude: </strong> {{ currentWeather.coord.lat }}</div>
      <div><strong>Weather condition </strong> {{ currentWeather.weather[0].description }}</div>
      <div><strong>Temperature Mid: </strong> {{  currentWeather.main.temp }} Farenheit</div>
      <div><strong>Temperature Max: </strong> {{  currentWeather.main.temp_max}} Farenheit</div>
      <div><strong>Temperature Min: </strong> {{  currentWeather.main.temp_min}} Farenheit</div>
      <div><strong>Humidity: </strong> {{  currentWeather.main.humidity }}%</div>
      <div><strong>Wind: </strong> {{  currentWeather.wind.speed }} mph</div>
     </div>
    </div>
  </div>
</template>

<script>
// import Axios
import axios from "axios"

export default {
  name: "Home",
  props: {
    msg: String,
  },
  data(){
    return {
      // current weather
      currentWeather: null,
      // current city
      currentCity: 'Montreal',
      // current country
      currentCountry: 'ca',
      unit: 'imperial'
    }
    this.$set(this.currentCity);
  },
  mounted(){
    // Make axios request to open weather api
    axios.get('https://api.openweathermap.org/data/2.5/weather?q='+this.currentCity+','+this.currentCountry+'&appid=fe435501a7f0d2f2172ccf5f139248f7&units='+this.unit+'')
    .then((response) => {
        // takes response object & stores it in currentWeather
        this.currentWeather = response.data

    })
    .catch(function (error) {
        // handle error
        console.log(error);
    })
  }
};
</script>

<style scoped lang="scss">

</style>

当我换到蒙特利尔、多伦多、渥太华、阿尔伯塔等城市时，我正在尝试。它相应地改变了预测。

原文由 Manuel Abascal 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 1

您没有 currentCity 更改的事件处理程序。因此，您的代码将在初始加载（即 mounted ）上运行，更改为 currentCity 不会更改任何天气数据。

您需要将 @change 添加到输入中，并在每次更改时获取新的 api 数据。

下面是示例代码

 new Vue({
  el: '#app',
  data() {
    return {
      // current weather
      currentWeather: null,
      // current city
      currentCity: 'Montreal',
      // current country
      currentCountry: 'ca',
      unit: 'imperial'
    }
    this.$set(this.currentCity);
  },
  methods: {
    getWeather() {
      // Make axios request to open weather api
      fetch('https://api.openweathermap.org/data/2.5/weather?q=' + this.currentCity + ',' + this.currentCountry + '&appid=fe435501a7f0d2f2172ccf5f139248f7&units=' + this.unit + '')
        .then(res => res.json()).then(data => {
          // takes response object & stores it in currentWeather
          this.currentWeather = data;

        })
        .catch(function(error) {
          // handle error
          console.log(error);
        })
    }
  },
  mounted() {
    this.getWeather();
  }
})

 <script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.min.js"></script>
<div id="app">
  <div class="home">
    <p>A weather app built Vuejs & Open Weather App. Made by Manuel Abascal</p>
    Search: <input type="text" v-model.lazy="currentCity" @change="getWeather">
    <div class="forecast" v-if="currentWeather && currentWeather.cod == 200">
      <!-- Forecast stat values -->
      <h2>Right now:</h2>
      <div><strong>City:</strong> {{ currentWeather.name }}</div>
      <div><strong>Longitude: </strong> {{ currentWeather.coord.lon }}</div>
      <div><strong>Latitude: </strong> {{ currentWeather.coord.lat }}</div>
      <div><strong>Weather condition </strong> {{ currentWeather.weather[0].description }}</div>
      <div><strong>Temperature Mid: </strong> {{ currentWeather.main.temp }} Farenheit</div>
      <div><strong>Temperature Max: </strong> {{ currentWeather.main.temp_max}} Farenheit</div>
      <div><strong>Temperature Min: </strong> {{ currentWeather.main.temp_min}} Farenheit</div>
      <div><strong>Humidity: </strong> {{ currentWeather.main.humidity }}%</div>
      <div><strong>Wind: </strong> {{ currentWeather.wind.speed }} mph</div>
    </div>
    <div v-else>
      "{{ currentCity }}" is not found
    </div>
  </div>
</div>

原文由 Ja9ad335h 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 2

你有两个问题：

首先，输入绑定 currentWeather.name 而不是 currentCity

其次，您在已安装的生命周期中有 axios 请求。即使 currentCity 模型发生变化，您也没有定义它发生变化时会发生什么。您需要在 currentCity 更改时添加一个 api 调用。

1. 将输入的模型更改为 currentCity <input type="text" v-model="currentCity">

2. 将 axios 请求移动到它自己的方法

   getWeather() {
       const url = 'https://api.openweathermap.org/data/2.5/weather?q=' + this.currentCity + ',' + this.currentCountry + '&appid=fe435501a7f0d2f2172ccf5f139248f7&units=' + this.unit + '';
       axios.get(url)
           .then((response) => {
               this.currentWeather = response.data;
           })
           .catch(function(error) {
               console.log(error);
           })
   }

1. 将输入更改绑定到 getWeather 方法

您可以将 getWeather 事件添加到 currentCity 输入的输入法中。

 <input type="text" v-model="currentCity" @input="getWeather">

或为当前天气添加观察者

watch: {
    currentCity: function(newCity, oldCity) {
        this.getWeather();
    }
}

奖金

每次您写下或擦除输入的字母时，该方法都会触发。添加去抖动或超时，它会在毫秒后触发。

 // import Axios
import axios from "axios"

export default {
    name: "Home",
    props: {
        msg: String,
    },
    data() {
        return {
            currentWeather: null,
            currentCity: 'Montreal',
            currentCountry: 'ca',
            unit: 'imperial'
        };
    },
    watch: {
        currentCity: function(newCity, oldCity) {
            this.debounceGetWeather();
        },
    },
    mounted() {
        this.getWeather();
    },
    methods: {
        debounceGetWeather() {
            setTimeout(() => {
                this.getWeather();
            }, 300);
        },
        getWeather() {
            axios.get('https://api.openweathermap.org/data/2.5/weather?q=' + this.currentCity + ',' + this.currentCountry + '&appid=fe435501a7f0d2f2172ccf5f139248f7&units=' + this.unit + '')
                .then((response) => {
                    this.currentWeather = response.data '
                })
                .catch(function(error) {
                    console.log(error);
                })
        },
    },
};

原文由 lntg 发布，翻译遵循 CC BY-SA 4.0 许可协议