Doing real-time calculations in a form using JavaScript
In this tutorial, we will learn how to perform calculations using JavaScript. It is quite often required to do calculations online in order forms, request quote forms and the like. This tutorial will show you how to use different form elements like drop-down list, radio button, check box and text box in a calculation. We will be using a ‘cake order form’ as an example. As the user makes selections in the form, the total price is calculated in real time.
Can JavaScript email a form?
NO! JavaScript can’t email a form! but, there are alternatives to send the form data to an email address. There is no direct method provided by JavaScript to send the data submitted in the form to an email address. The main concern for not providing a ‘JavaScript email form’ feature is security. Suppose there is a feature in JavaScript to send email. Some malicious coder can write a script to send email to some address immediately when you visit their page.
How to Submit a Form Using JavaScript
Generally, a form is submitted when the user presses a submit button. However, sometimes, you may need to submit the form programmatically using JavaScript. JavaScript provides the form object that contains the submit() method. Use the ‘id’ of the form to get the form object. For example, if the name of your form is ‘myform’, the JavaScript code for the submit call is: document.forms["myform"].submit(); But, how to identify a form? Give an id attribute in the form tag
How to get the value of a form element : check box and radio button
This is the third article in the getting form element values using JavaScript series. In this article we will see how to get the value of check box and radio button. Getting a radio element and it’s checked value Radio buttons in a form can be grouped together using the same name attribute, such that, if one of them is checked, all the others are automatically un-checked. Let us look at an example:
How to get the value of a form element : Drop downs and lists
This article is in continuation of getting form element values using JavaScript series. Drop down list We can obtain a reference to this type of element using its name: oSelectOne = oForm.elements["select_one_element_name"]; To get the index of the selected option in the JavaScript options array of the select element, we can use the selectedIndex property of the select element object: index = oSelectOne.selectedIndex; We can now use this index to determine the value of the selected option:
How to get the value of a form element using JavaScript
Please refer article: how to get JavaScript form object for information on getting a reference to the form object. In this article we demonstrate the use of JavaScript for accessing the values of form elements. Later, we will demonstrate all the concepts using a real world example. Text input element To obtain a reference to a text input element, here is some sample code: oText = oForm.elements["text_element_name"]; OR oText = oForm.
Using JavaScript to access form objects when there are multiple forms
In order to access a form through JavaScript, we need to obtain a reference to the form object. One obvious way to approach, is to use the getElementById method. For instance, if we had a form with the id attribute "subscribe_frm", we could access the form in this way: var oForm = document.getElementById('subscribe_frm'); However, this approach has the limitation that the <form> tag must have an id attribute, as the getElementById method needs the id of an element in order to locate it in the DOM tree.
Using JavaScript to reset or clear a form
Using an HTML ‘Reset’ button is an easy way to reset all form fields to their default values. For instance, the code snippet below shows an <input> field of type “reset”, which on being clicked resets all the form fields: <input type="reset" value="Reset Form"> In fact, we could also use the form’s reset() method to achieve the same effect, using a simple button element: <input type="button" value="Reset Form" onClick="this.form.reset()" /> These methods are very convenient to use, but they do not provide the functionality of clearing all the fields, including their default values.
How to set the value of a form element using Javascript
As we have seen in earlier articles, in order to work with forms in JavaScript, it is imperative to obtain references to the form object and its elements. In this article, we will be using the forms collection of the document object and the elements collection of the form object to set the values of the form elements. The syntax for accessing the form object is as below: oFormObject = document.
How to set the value of a form field using Javascript PII
This is in continuation of the article: set the value of a form element using Javascript. In this section, we will see how to set the value of other input fields like hidden field, drop down list etc Setting the value of a hidden field using Javascript As in the case of ’textarea’ and ’text’ input elements, in order to set the value of a hidden input element in a form, we can use the following syntax:
How to set the value of a form field using Javascript PIII
This is in continuation of the previous article: How to set the value of a form field using JavaScript Selecting options of a select element through javascript In Javascript, since each <option> tag inside a <select> tag, is placed in the options array of the select object, we can access each select option using a construct such as: selectObject.options[index] where, “index” refers to the position of the option in the array.
How to use getElementById to get the elements in a form
There are many ways of accessing form elements, of which the easiest is by using the cross-browser W3C DOM document.getElementById() method. Before we learn more about this method, it would be useful to know something about the Document Object Model (DOM), the concept of HTML nodes or elements, and the concept of containers. Each time you load an HTML page, the web browser generates an internal representation of the page in the form of an inverted tree structure.
Easy method to submit a form with file uploads using Javascript
Submitting a form with file uploads using JavaScript can be done using the FormData API. This API allows you to easily create and manage form data and upload files to a server. Here is a step-by-step guide on how to submit a form with file uploads using JavaScript: Step 1: Create HTML form Create an HTML form that contains file input fields, as shown below: <form id="myForm"> <input type="text" name="name" placeholder="Name"> <input type="file" name="file"> <button type="submit">Submit</button> </form> Step 2: Add event listener Add an event listener to the form’s submit event to prevent the default form submission behavior and handle the form submission using JavaScript.
How to keep checkbox values after form is submitted in Javascript
When working with forms in web applications, it’s common to encounter a situation where you want to retain the user’s selected checkbox values even after the form has been submitted. This tutorial will guide you on how to keep the checkbox value after a form submit in JavaScript. We’ll be using localStorage to store the selected checkbox values and retrieve them when the page is reloaded. First, let’s create a simple HTML form with a few checkboxes:
How to Store Multiple Form Data in LocalStorage Using JavaScript
LocalStorage allows you to store data on the client-side, which persists even after the browser is closed. In this tutorial, we’ll walk through the process of storing multiple form data in LocalStorage using JavaScript. First, create an HTML file with a form containing some input fields. For this example, let’s create a simple registration form. <form id="registrationForm"> <label for="fullName">Full Name:</label> <input type="text" id="fullName" name="fullName" required> <label for="email">Email:</label> <input type="email" id="email" name="email" required> <label for="password">Password:</label> <input type="password" id="password" name="password" required> <button type="submit">Register</button> </form> JavaScript code for storing form data document.
Javascript submit a form and stay on page
In some cases, you may want to submit the form without leaving the current page, allowing users to continue interacting with the page without interruption. In this article, we’ll explore how to use JavaScript to submit a form and stay on the same page. Understanding the Basics of Form Submission Before diving into the specifics of submitting a form without leaving the page, it’s important to understand how form submission works in general.
Submit a form on select onchange
Step 1: Create a Form and Dropdown Create an HTML form that includes a dropdown menu with options. Give your form an id so that it can be easily targeted with JavaScript later. <form action="https://show.ratufa.io" method="post" id="myForm"> <select id="myDropdown" class="form-select" name="dropdown"> <option selected>Open this select menu</option> <option value="1">One</option> <option value="2">Two</option> <option value="3">Three</option> </select> </form> Step 2: Add Event Listener to Dropdown Add an event listener to the dropdown menu that listens for a change in its value.
Submit a form using link
Submitting a form using a link in JavaScript can be done using the Fetch API. Step 1: Create a Form First, create an HTML form that includes the inputs you want. For example: <h2>Contact Us</h2> <div class="p-4"> <form id="myform"> <div class="form-group"> <label for="myform_name">Name</label> <input type="text" name="name" class="form-control" id="myform_name" placeholder="Your Name"> </div> <div class="form-group"> <label for="myform_email">Email address:</label> <input type="email" name="email" class="form-control" id="myform_email" placeholder="Your email"> </div> <div class="form-group"> <label for="myform_message">Message</label> <textarea class="form-control" name="message" id="myform_message" rows="3"></textarea> </div> <a href="#" id="myLink" >Submit</a> </form> </div> This form has two input fields for name, email, a message, and a link to submit the form.
Submit a form using post method using Javascript
Submitting a form using the POST method in JavaScript can be done using the Fetch API, which is a newer and simpler way to make HTTP requests. In this tutorial, we’ll go through the steps required to submit a form using the POST method with the Fetch API. Step 1: Create a Form First, create an HTML form that includes the inputs you want to send via POST. For example: