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Awaiting till user finishes writing to input field in Vue.js

I have a QR code creating page. I want my QR codes to be created dynamically by user input. But I don’t want to instantly create a QR code. I want to wait my user to finish writing then after one second i will generate the QR code. So I have a template like below:

<div class="app">
    <qrcode-vue :value="genaratedQrCode"></qrcode-vue>
    <input type="text" v-model="qrCodeInput" />
</div>

And my script:

import QrcodeVue from 'qrcode.vue';

export default {
    data() {
        return {
            genaratedQrCode: '',
            qrCodeInput: '',
            isInputFunctionRunning: false
        }
    },
    watch: {
        async qrCodeInput() {
            if (this.isInputFunctionRunning) {
                return;
            }

            this.isInputFunctionRunning = true;

            await new Promise(r => setTimeout(r, 1000));

            this.genaratedQrCode = this.qrCodeInput;

            this.isInputFunctionRunning = false;
        }
    }
    components: {
        QrcodeVue,
    },
}

Apparently the code is not working. It generated the QR code every one seconds. What I want is waiting till user finished, then updating after 1 seconds.

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Answer

You have to use .lazy modifier :

<input type="text" v-model.lazy="qrCodeInput" />

If you want to wait some delay try this :

import QrcodeVue from 'qrcode.vue';

function debounce (fn, delay) {
  var timeoutID = null
  return function () {
    clearTimeout(timeoutID)
    var args = arguments
    var that = this
    timeoutID = setTimeout(function () {
      fn.apply(that, args)
    }, delay)
  }
}



export default {
    data() {
        return {
            genaratedQrCode: '',
            qrCodeInput: '',
            isInputFunctionRunning: false
        }
    },
    watch: {
        qrCodeInput:debounce(function() {
            if (this.isInputFunctionRunning) {
                return;
            }

            this.isInputFunctionRunning = true;

            this.genaratedQrCode = this.qrCodeInput;

            this.isInputFunctionRunning = false;
        },1000)
    }
    components: {
        QrcodeVue,
    },
}

This is based on this answer;

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