How to wait for request and user input?-CodePudding

Let's say when a component loads I make an async request. That component also has a submit button that the user can press which triggers a function that relies on the result of that original request. How do I delay executing the triggered function until the async request is finished?

If that doesn't make sense let me give an example. MyComponent makes an async request getRandomColor() on mounted. MyComponent's template has <button @click="handleClick">. handleClick calls some function saveColor(). How do I make sure that saveColor() is not called until my async getRandomColor() is finished?

I'm currently using Vue.js but I think this question applies to all of javascript.

CodePudding user response：

You can achieve this by adding :disabled attribute in your button element. The value of :disabled will be based on the response. i.e. If response will be there then enabled it otherwise disabled.

Working Demo :

const app = Vue.createApp({
  el: '#app',
  data() {
    return {
        buttonText: 'Call Me!',
      apiResponse: [],
      isDisabled: false
    }
  },
  methods: {
    saveColor() {
        console.log('saveColor method call');
    }
  },
  mounted() {
    axios.get("https://jsonplaceholder.typicode.com/users").then(response => {
      this.apiResponse = response.data; // Here we are getting proper response. hence, button is getting enabled.
    }).catch((error) => {
        console.warn('API error');
        });
  }
})
app.mount('#app')

<script src="https://unpkg.com/vue"></script>
<script src="https://unpkg.com/axios/dist/axios.min.js"></script>

<div id="app">
  <button v-on:click="saveColor()" :disabled="!apiResponse.length">{{ buttonText }}</button>
</div>

Adding below snippet as per the comment added by the author of the post.

What if I didn't want to use the disabled button? Is there a way to make the button handler wait for the request to finish before it continues execution?

const app = Vue.createApp({
  el: '#app',
  data() {
    return {
        buttonText: 'Call Me!',
      apiResponse: [],
      isDisabled: false
    }
  },
  methods: {
    saveColor() {
        console.log('saveColor method call');
    }
  },
  mounted() {
    axios.get("https://jsonplaceholder.typicode.com/users").then(response => {
      this.apiResponse = response.data; // Here we are getting proper response. hence, button is getting enabled.
    }).catch((error) => {
        console.warn('API error');
        });
  }
})
app.mount('#app')

<script src="https://unpkg.com/vue"></script>
<script src="https://unpkg.com/axios/dist/axios.min.js"></script>

<div id="app">
  <button v-on:click.prevent="apiResponse.length ? saveColor() : {}">{{ buttonText }}</button>
</div>