How to add an attribute dynamically in VueJs

Question

I'm using vuejs and I wanna know how to have control on inputs (add disabled attribute when necessary). Is there any way to add dynamically attribute in vuejs ? Below my Textfield component :

    <template>
     <input type="text" placeholder="{{ placeholder }}" v-model="value">
    </template>
    <script>
    export default  {
      props: {
       disabled: {type: Boolean, default: false},
       placeholder: {type: String, default: ""},
       value: {twoWay: true, default: ""}
      }
     }
    </script>

Usage :

<textfield placeholder="Name" value.sync="el.name" :disabled="true"></textfield>

Answer 1

You can bind it to a variable using v-bind:disabled="foo" or :disabled="foo" for short:

<textfield label="Name" value.sync="el.name" :disabled="myVar">

Then in Vue you can just set this.myVar = true and it will disable the input.

Edit: add this to your template:

<template>
  <input type="text" :disabled="disabled" :placeholder="placeholder" v-model="value">
</template>

Answer 2

As pointed out, you don't need dynamic attributes in your case.

But well, you asked if it is possible, and the answer is yes. You can have dynamic attributes, as of 2.6.0.

Example:

<a v-bind:[attributeName]="whatever">

It is documented here

Answer 3

I am trying to figure out how to set the attribute of the html tags from the array value dynamically when using the Vue v-for loop.

What I am going to show:

Example

1. There are 3 div elements with different background colors from array value(not static).

2. Each divs have a input tag and change the value when the user input value

   • The first div's input converts lowercase to uppercase.
   • second represents the mood, if enter 'happy', present 'good'. if enter 'sad', output 'bad'
   • The third div input doubles the input value.
   {{ box.outputData }} Rounded Box

   new Vue({
    el: "#app",
     data: {
       isRounded: false,
         boxes: [
           {
             inputData: "",
             outputData: "",
             color: "green",
             operation: "uppercase"
           },
           {
             inputData: "",
             outputData: "",
             color: "red",
             operation: "feeling"
           },
           {
             inputData: "",
             outputData: "",
             color: "blue",
             operation: "multiple"
           }
         ],
         feeling: {
           good: ["happy", "joyful", "calm"],
           bad: ["sad", "mad", "depressed"]
         }
     },
     methods: {
       toggle: function(todo){
           todo.done = !todo.done
       }
     },
     watch: {
       boxes: {
         deep: true,
         immediate: true,
         handler: function(val) {
           this.boxes.map(box => {
             if (box.operation === "uppercase")
               box.outputData = box.inputData.toUpperCase();
             else if (box.operation === "feeling") {
               box.outputData = this.feeling.good.includes(box.inputData)
                 ? "GOOD"
                 : this.feeling.bad.includes(box.inputData)
                 ? "BAD"
                 : "";
             } else if (box.operation === "multiple") {
               if (box.inputData == "") box.outputData = "";
               else box.outputData = parseInt(box.inputData) * 2;
             }
           });
         }
       }
     },
     mounted() {
       for (var i = 0; i < this.numBox; i++) {
         this.boxValue[i] = "";
         this.bxData[i] = "";
       }
     },
   })
   
   
   
   .clearfix{
    clear: both;
   }
   .full-width{
     width:100%;
   }
   input {
     background: transparent;
     text-decoration: underline;
     color: white;
     border: none;
     text-align: center;
     font-size:30px;
   }
   .box {
     float:left;
     color: white;
     width: 24%;
     margin-right: 1%;
     padding: 20px;
     background: blue;
     height: 100px;
   }
   .box-output {
     width: 100%;
     text-align: center;
     font-size:30px;
   }
   .box-rounded {
     border-radius: 50px;
   }
   

Answer 4

base one condition we can define or change attributes in vue

Please refer official document for the same https://v2.vuejs.org/v2/guide/syntax.html#Attributes

Answer 5

ok, try this if you are passing i18 -

:placeholder="$t('languagePlaceholder')"

Answer 6

To set an attribute whose name is dynamic (e.g. a variable), one can pass a dynamic argument to v-bind using square brackets.

<div :[attrName]="attrValue">Content...</div>

This is the shorthand for v-bind:[attrName]="attrValue".

See Vue SFC Playground example

Answer 7

I did that with checkboxes:

 <select id="newTwootType" v-model="state.selectedTwootType">
      <option 
      :value="option.value" 
      v-for="(option, index) in state.twootTypes" 
      :key="index">
        {{ option.name }}
      </option>
    </select>

my scripts

export default {
name: 'CreateNewTwootPanel',
setup(props, ctx) {
  const state = reactive({  
      selectedTwootType: 'instant',
      twootTypes: [
          { value: 'draft', name: 'Draft' },
          { value: 'instant', name: 'Instant Twoot' }
      ],
  })

  return {
    state,
    }
  }
}

Answer 8

Vue3 Example with error:

BaseInput.vue

<template>
    <div>
        <label>{{ label }}</label>
        <input v-bind="$attrs" :placeholder="label" :value="modelValue" @input="$emit('update:modelValue', $event.target.value)">
        <p v-if="error">{{ error }}</p>
    </div>
</template>

<script setup>
defineProps(['label', 'modelValue', 'error'])
defineEmits(['update:modelValue'])
</script>

v-bind="$attrs" is necessary if you want to pass attributes to child tag or there are multiple tag in <template> you can specify with tag need to get attributes.

Login.vue

<template>
    <form @focusout="validateForm" @submit.prevent="onSubmit">
        <BaseTitle title="Log in" h="h1"/>
        <BaseInput type="email" v-model="email" label="Email" :error="emailError"/>
        <BaseInput type="password" v-model="password" label="Password" :error="passwordError"/>
        <BaseButton type="submit" label="LogIn" />
    </form>
</template>

<script setup lang="ts">

const email = ref('')
const password = ref('')
const emailError = ref('')
const passwordError = ref('')

function validateForm() {
    emailError.value = "Error"
}

function onSubmit() {
    signIn({ email: email.value, password: password.value})
}
</script>