Steps for showing an error prompt when input is invalid:

In my Vue 3 application, I have implemented a simple calculator that divides a dividend by a divisor and displays the quotient and remainder. Users can adjust any of the four numbers to perform different calculations.

<div id="app">
<input type="text" v-model.number="dividend"> divided by <input type="text" v-model.number="divisor">
is
<input type="text" v-model.number="quotient"> remainder <input type="text" v-model.number="remainder">
</div>
<script src="https://unpkg.com/vue@next"></script>
<script>
Vue.createApp({
  data() { return {
    dividend: 100,
    divisor: 7
  }},
  computed: {
      quotient: {
        get: function() { return Math.floor(this.dividend / this.divisor); },
        set: function(v) { this.dividend = v * this.divisor + this.remainder; }
      },
      remainder: {
        get: function() { return this.dividend % this.divisor; },
        set: function(v) { if (v < this.divisor) this.dividend = this.quotient * this.divisor + v; }
      }
    }
}).mount("#app");
</script>

However, when users input a remainder greater than or equal to the divisor, the remainder is automatically adjusted. For example, if they enter 9 as the remainder when the divisor is 7, it will be displayed as 2 with the quotient increasing by 1. This may seem counterintuitive, so I modified the setter for the remainder:

set: function(v) { if (v < this.divisor) this.dividend = this.quotient * this.divisor + v; }

Now, if an invalid remainder is entered, the calculation does not update until the user corrects it or modifies another value. However, in such cases, I would like to show an error message to guide the user. How can I go about implementing this feature?

Answer №1

observe has the ability to monitor changes.

Introduce a new property to manage the state and validate the input.

<div v-if="!isValidInput">Display your warning messages here.</div>

data() { 
 return {
    dividend: 100,
    divisor: 7,
    isValidInput: true,
  }},
watch: {
    'dividend': function(val){
      if (your_conditions) {
        this.isValidInput = false;
      }
    },
    'divisor': function(val){
      if (your_conditions) {
        this.isValidInput = false;
      }
    }

Similar questions

If you have not found the answer to your question or you are interested in this topic, then look at other similar questions below or use the search

Is there a way to reverse a string in Javascript without using any built-in functions?

I am looking for a way to reverse a string without using built-in functions like split, reverse, and join. I came across this code snippet on Stack Overflow (), but I'm having trouble understanding what the code does on the fourth line. I need more cl ...

Update the background URL of a div element using an HTML tag

My question is about a CSS div with set dimensions and background that I want to change on hover. I am aware that this seems like a simple task, but what I really want to do is retrieve the background sources from within the HTML tag itself. For example: ...

Prevent side-to-side scrolling on elements that exceed the width of the screen

I am working on building a navigation system similar to Google Play, where there are fixed tabs for browsing through the app. I have created a container div that holds various content sections. <div id="container"> <div class="section"> .. ...

Comparing the start and end times in tabular or array input using Yii2

Can I compare the start and end times in the Yii2 client/ajax validation for my form? This is how my view file code looks: <?php foreach ($model->weekDaysList as $index => $value) : ?> <div class="row"> <div class="col-sm ...

sending a pair of variables via jQuery and AJAX

Having difficulty posting two variables using ajax and jquery when a button on a confirm window is pressed. Each variable can be displayed separately, but not both at the same time. UPDATE - Issue resolved. I overlooked including a necessary file. My mist ...

What are the steps to utilize the .find() method to search for documents in a database that belong to the current user

My back-end code for the 'get' request to my '/logs' collection returns data in an array labeled "times": router.get('/', (req, res) => { time .find({'userName': req.params.userName}) .exec() .then(times => ...

Combining Import and Require in a Node JS File

Having some trouble with the normalize-url package. It needs to be imported instead of required since it's not supported in ES module. I tried to work around this by adding some code I found online, but it doesn't seem to be fixing the issue for ...

Create an input element using JavaScript/jQuery

Looking for some help with Javascript on a simple task. When a specific option is chosen, I want to add an input field to a div element. <select name="amount" > <option value="50">50$</option> <option value="100">100$</o ...

Unable to complete the task of executing com.github.eirslett:frontend-maven-plugin:1.6:install-node-and-npm (install node and npm)

I'm encountering an issue with Maven that's been causing some trouble: [ERROR] Failed to execute goal com.github.eirslett:frontend-maven-plugin:1.6:install-node-and-npm (install node and npm) on project xxx-frontend: Could not download Node.js: ...

Best practices for utilizing the getTile() method within Google Maps

I have a question about storing markers in a database using tile IDs. The goal is to display all the markers associated with a specific tile when it is displayed on a map. Initially, I created a code that was not working correctly. It only requested one ...

Is there a way to position two Grid elements to the left and one to the right in Material UI, especially if the first Grid element has a specified width

I'm currently using Material UI and have a Grid layout with three items. The left item needs to have a fixed width of 240px and be aligned to the left. The middle item should be left justified and can have any width, containing buttons that I've ...

MUI version 5 - Checkboxes are receiving a variety of unique classes

After recently upgrading from Mui v4 to v5, I've noticed a strange behavior with checkboxes. Upon inspecting the DOM differences between the two versions, it appears that some additional classes are now being applied in v5 and the extra span with the ...

Simple JavaScript numeric input field

Hey there, I'm a beginner learning JavaScript. I'm currently working on creating a program that adds numbers input through text fields. If you want to check out the HTML code, visit this link on JS Fiddle: http://jsfiddle.net/fCXMt/ My questio ...

Tips for handling notifications that have been read and unread in a React application

In my current project using React JS, I am tasked with creating a notifications component that will display account-related activities. The notifications need to be sorted into read and unread categories. My main question is how should I manage the read a ...

The functionality of string replacement is ineffective in the Safari browser

When using the code "MM/DD/YYYY".replace(/.?YYYY.?/, ''); , Chrome displays MM/DD, while Safari shows an empty string. Why does this difference occur? Is there a method that will produce consistent results across all browsers? ...

Excess space creating horizontal and vertical scrolling issues on an HTML webpage

Currently, I am experimenting with CSS effects. In my code, I have included div elements to display balls on the document body, each with random sizes and colors. However, an unexpected issue has arisen - excess scroll space is being generated due to the c ...

The functionality of Skrollr on mobile is currently not working properly due to the inability to prevent default actions

Encountering the following error on all chromium browsers while using the Skrollr library and accessing the website through mobile: "[Intervention] Unable to preventDefault inside passive event listener due to target being treated as passive. See < ...

How can I get my ReactJS file to properly show the user's email address?

After clicking submit, I encountered errors in both localhost (3000 and htdocs). When using localhost 3000, upon hitting submit, I was redirected to http://localhost:3000/index.php with the error message: Cannot POST /index.php While in localhost via the ...

Customizing Material UI Select for background and focus colors

I am looking to customize the appearance of the select component by changing the background color to "grey", as well as adjusting the label and border colors from blue to a different color when clicking on the select box. Can anyone assist me with this? B ...

There seems to be a syntax error in the AngularJS/Bootstrap code, with an unrecognized expression

Hey there, I'm currently working on developing an application using Angular and Bootstrap. I've successfully implemented ui.router for routing purposes, but I've encountered an issue when loading the Bootstrap library. The console is showing ...