What is the best way to use v-model without using it in the main app.js file? - laravel

Question

I was wondering i have this code inside my blade file:
<input type="text" class="form-control" :model="productname" id="name" name="name" aria-describedby="emailHelp" placeholder="Title" value="{{ old('name') }}" required>
and i want to create an 2 way data binding, so when user submitted 3 or more character to get an green background of this input field, but when they are less to get a red background.
I tried to do this with vue-component, but it seems for whatever reason the vue-component does not have access to the main #app id which is assign to the main app blade template in order all vue code to have access to the html code and change it. I have created an vue-component called Upload inside ressources/assests/js/components/Upload.js, but when i write this code:
<template>
</template>
<script>
export default {
data() {
return {
productname: '',
};
},
mounted() {
console.log('Upload component', this.message);
}
}
</script>
and added of course to app.js like that Vue.component('upload-component', require('./components/Upload.vue'));
and run - npm run dev to compile the code i am getting this error:
[Vue warn]: Property or method "productname" is not defined on the instance but referenced during render. Make sure that this property is reactive, either in the data option, or for class-based components, by initializing the property. See: https://v2.vuejs.org/v2/guide/reactivity.html#Declaring-Reactive-Properties.
Whatever when i write this code inside the main app.js file (resources/assests/js/app.js):
const app = new Vue({
el: '#app',
data() {
return {
productname: '',
};
},
});
everything is working fine and i dont get any errors, but i dont want that, as imagine for my website/app i have to have for example 100 v-models and i dont want to put them all inside the main app.js file. Is there other way to do this?
Can i still somehow make it work inside the vue component, so the component can see the v-model and not giving me this error?
If not, can i make it work and use vue inside the blade file something like that?
new Vue({
el: '#form',
data: {
productname: ''
}
});
but this code its not working. Thanks!

Answer 1

It's a bit tricky to make out what you are doing exactly, but your error is related to having no data property 'message', you have only a property called 'productname'.
If you want your component to communicate up to its parents or siblings you should read into emitting events in vue using
this.$emit