samuel toh samuel toh -4 years ago 574
Javascript Question

How to solve [Vue warn]: props must be strings when using array syntax?

My view is like this :

<div class="col-md-8">
...
<star :value="{{ $data['rating'] }}" :user="{{ $data['user_id']></star>
...
</div>


My star component is like this :

<template>
<span class="rating">
<template v-for="item in items">
<label class="radio-inline input-star" :class="{'is-selected': ((value >= item.value) && value != null), 'is-disabled': disabled}">
<input type="radio" class="input-rating" name="input-rating" v-bind:value="item.value" v-model="value" :disabled="disabled" @click="rate(item.value)">
</label>
</template>
</span>
</template>
<script>
export default{
props: [{'value': null,'disabled': Boolean}, 'user'],
data(){
return{
items: [
{value: 5},
{value: 4},
{value: 3},
{value: 2},
{value: 1}
],
temp_value: null,
}
},
methods:{
rate: function (star) {
var self = this;
if (!this.disabled) {
this.$http.post(window.BaseUrl + '/star', {star: star}).then(function (response) {
console.log('submitted');
});
this.temp_value = star;
return this.value = star;
}
},
}
}
</script>


My css is like this :

span.rating {
direction: rtl;
display: inline-block;
}

span.rating .input-star {
background: url("../img/star.png") 0 -16px;
padding-left: 0;
margin-left: 0;
width: 16px;
height: 16px;
}

span.rating .input-star:hover, span.rating .input-star:hover ~ .input-star {
background-position: 0 0;
}

span.rating .is-selected{
background-position: 0 0;
}

span.rating .is-disabled{
cursor: default;
}

span.rating .input-star .input-rating {
display: none;
}


When I click the star, there exist error on the console like this :


[Vue warn]: props must be strings when using array syntax.

[Vue warn]: Property or method "star" is not defined on the instance
but referenced during render. Make sure to declare reactive data
properties in the data option. (found in at
C:\xampp\htdocs\myshop\resources\assets\js\components\Star.vue)

[Vue warn]: Property or method "disabled" is not defined on the
instance but referenced during render. Make sure to declare reactive
data properties in the data option. (found in at
C:\xampp\htdocs\myshop\resources\assets\js\components\Star.vue)


How can I solve it?

Answer Source

There are several errors in your code.

First, you don't need the braces in props:

<star :value="{{ $data['rating'] }}" :user="{{ $data['user_id'] }}"></star>
         <!-- ^^ syntax error -->

just:

<star :value="$data['rating']" :user="$data['user_id']"></star>

and this can be simplified to:

<star :value="rating" :user="user_id"></star>

Another error is the declaration of props. That's the reason why Vue told you it can't recognize disabled and value.

The simplest way is props: ['value', 'disabled', 'user'],

If you want to add validations, follow the documentation here: https://vuejs.org/v2/guide/components.html#Prop-Validation

Another problem is that you are mutating props directly.

<input ... v-model="value" ...>

The value is a prop. The flow of props is one way down. A component should not mutate its props.

If you want to send the value back to parent, use events. Here is the documentation of events: https://vuejs.org/v2/guide/components.html#Custom-Events

or see my previous answer: Update parent model from child component Vue

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