This library provides a simple API to manipulate a form or its related elements with JavaScript. Supports IE10+, all modern browsers, and mobile.
It's important for you to use native form elements (i.e. <select>, <input>, etc) because they come with critical built-in
logic needed for the interactions that users expect. Like tabbing to fields, pressing enter or spacebar to commit a
dropdown item, mobile keyboard input triggering, etc.
- Automatic form data binding (JSON data and JS object literals)
- Use CSS to easily customize hard-to-style native elements (i.e. dropdowns)
- Listen to user events on forms
- Easily change and update form elements and their values with JavaScript
- Trigger events programmatically
- Checkboxes
- Radio Buttons
- Input Fields
- Dropdowns (Select Elements)
- Text Areas
- Entire forms
You can quickly start using the Form class as a standalone package, by using one of the pre-built javascript files. Alternatively, you can also use the source files directly if you are running your own build processes.
Let's say you wanted to style a dropdown menu with the following html:
<select>
<option value="MD">Maryland</option>
<option value="VA" selected>Virginia</option>
<option value="DC">Washington, DC</option>
</select>With this library, you can do this:
var Dropdown = require('form-js').Dropdown;
var dropdown = new Dropdown({
el: document.getElementsByTagName('select')[0]
});Which will change your HTML into this:
<div class="dropdown-wrapper">
<div class="dropdown-container">
<div class="dropdown-value-container">Virginia</div>
<div class="dropdown-option-container">
<div class="dropdown-option" data-value="MD">Maryland</div>
<div class="dropdown-option dropdown-option-selected" data-value="VA">Virginia</div>
<div class="dropdown-option" data-value="DC">Washington, DC</div>
</div>
</div>
<select>
<option value="MD">Maryland</option>
<option value="VA" selected>Virginia</option>
<option value="DC">Washington, DC</option>
</select>
</div>Then you can style the dropdown using CSS (and just hide the <select> element).
Each class comes with a set of utility methods so you can change the elements via JS. Using the example above, you could do the following:
// set the selected value programmatically
dropdown.setValue('DC');
// get the new data value
dropdown.getValue(); // => "DC"
// get the display value
dropdown.getDisplayValue(); // => "Washington, DC"You can also listen to events on form elements. Given the following input element...
<input type="text" value="" placeholder="Enter text here" />You can do the following:
var InputField = require('form-js').InputField;
var inputField = new InputField({
el: document.getElementsByTagName('input')[0],
onChange: function (el) {
// user has finished typing into the field!
},
onKeyDownChange: function (el) {
// the user has typed a key into the field!
}
});
// set the value
inputField.setValue('My text'); // set new value
// get the new value
inputField.getValue(); // => "My text"Suppose you have this HTML:
<form class="debt-info-form">
<input type="text" name="first_name" value="" />
<select name="loan_type">
<option value="CC">Credit Card</option>
<option value="Mortgage">Mortgage</option>
<option value="HELO">HELO</option>
<option value="Student Loan">Student Loan</option>
</select>
</form>You can detect when a user changes any of the form's elements like so:
var Form = require('form-js').Form;
var form = new Form({
el: document.body.getElementsByClassName('debt-info-form')[0],
onValueChange: function (val, el) {
// a value has been changed!
console.log('new value: ' + val);
}
});
form.setup();Examples can be found in the examples page.
The form class allows you to instantiate an entire form (along with its nested elements: <input>, <textarea>, <select>).
To create an instance of a form, you need to pass the form element (and a set of options if you'd like).
let formElement = document.getElementByTagName('form')[0];
var form = new Form({
el: formElement
});Setup just does a few standard setup tasks, like bind event listeners and such. This method is necessary after instantiation in order to begin working with your form instance.
A utility method to grab a serialized object of all of the form elements and their current values. See below.
<form id="my-form">
<input type="text" name="location" value="Arlington, VA" required />
</form>let formElement = document.getElementById('my-form');
var form = new Form({
el: formElement
});
form.setup();
console.log(form.getCurrentValues());
/*
[{
disabled: false,
name: "location",
required: false,
value: "Arlington, VA"
}]
*/Clears all fields inside of the form. It also unchecks any checkboxes and resets any dropdown selections.
<form id="my-form">
<input type="text" id="location-input" name="location" value="Arlington, VA" required />
<input type="text" id="name-input" name="name" value="John Smith" required />
<input type="number" name="age" value="Arlington, VA" required />
</form>let formElement = document.getElementById('my-form');
let locationInput = document.getElementById('location-input');
let nameInput = document.getElementById('name-input');
var form = new Form({
el: formElement
});
form.setup();
locationInput.value // => "Arlington, VA"
nameInput.value // => "John Smith"
form.clear();
locationInput.value // => ""
nameInput.value // => ""Disables all form elements.
Re-enables all form elements.
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