Before doing customizations, do the following.
- Set Magento to developer mode
- Do not edit default Magento code, instead add customizations in a
separate module
- Do not use Ui for your custom module name
**Step 1: Create the JS implementation of the form UI component**
In your `<your_module_dir>/view/frontend/web/js/view/` directory, create a .js file implementing the form.
/*global define*/
define([
'Magento_Ui/js/form/form'
], function(Component) {
'use strict';
return Component.extend({
initialize: function () {
this._super();
// component initialization logic
return this;
},
/**
* Form submit handler
*
* This method can have any name.
*/
onSubmit: function() {
// trigger form validation
this.source.set('params.invalid', false);
this.source.trigger('customCheckoutForm.data.validate');
// verify that form data is valid
if (!this.source.get('params.invalid')) {
// data is retrieved from data provider by value of the customScope property
var formData = this.source.get('customCheckoutForm');
// do something with form data
console.dir(formData);
}
}
});
});
**Step 2: Create the HTML template**
Add the `knockout.js` HTML template for the form component under the `<your_module_dir>/view/frontend/web/`template directory.
**Example:**
<div>
<form id="custom-checkout-form" class="form" data-bind="attr: {'data-hasrequired': $t('* Required Fields')}">
<fieldset class="fieldset">
<legend data-bind="i18n: 'Custom Checkout Form'"></legend>
<!-- ko foreach: getRegion('custom-checkout-form-fields') -->
<!-- ko template: getTemplate() --><!-- /ko -->
<!--/ko-->
</fieldset>
<button type="reset">
<span data-bind="i18n: 'Reset'"></span>
</button>
<button type="button" data-bind="click: onSubmit" class="action">
<span data-bind="i18n: 'Submit'"></span>
</button>
</form>
</div>
**Clear files after modification**
If you modify your custom .html template after it was applied on the store pages, the changes will not apply until you do the following:
Delete all files in the `pub/static/frontend` and `var/view_preprocessed` directories.
Reload the pages.
**Step 3: Declare the form in the checkout page layout**
To add content to the Shipping Information step, create a `checkout_index_index.xml` layout update in the `<your_module_dir>/view/frontend/layout/`.
It should be similar to the following.
<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
<body>
<referenceBlock name="checkout.root">
<arguments>
<argument name="jsLayout" xsi:type="array">
<item name="components" xsi:type="array">
<item name="checkout" xsi:type="array">
<item name="children" xsi:type="array">
<item name="steps" xsi:type="array">
<item name="children" xsi:type="array">
<item name="shipping-step" xsi:type="array">
<item name="children" xsi:type="array">
<item name="shippingAddress" xsi:type="array">
<item name="children" xsi:type="array">
<item name="before-form" xsi:type="array">
<item name="children" xsi:type="array">
<!-- Your form declaration here -->
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</argument>
</arguments>
</referenceBlock>
</body>
</page>
**Static forms:**
The following code sample shows configuration of the form that contains four fields: text input, select, checkbox, and date. This form uses checkout data provider (checkoutProvider) that is introduced in the Magento_Checkout module:
<item name="custom-checkout-form-container" xsi:type="array">
<item name="component" xsi:type="string">%your_module_dir%/js/view/custom-checkout-form</item>
<item name="provider" xsi:type="string">checkoutProvider</item>
<item name="config" xsi:type="array">
<item name="template" xsi:type="string">%your_module_dir%/custom-checkout-form</item>
</item>
<item name="children" xsi:type="array">
<item name="custom-checkout-form-fieldset" xsi:type="array">
<!-- uiComponent is used as a wrapper for form fields (its template will render all children as a list) -->
<item name="component" xsi:type="string">uiComponent</item>
<!-- the following display area is used in template (see below) -->
<item name="displayArea" xsi:type="string">custom-checkout-form-fields</item>
<item name="children" xsi:type="array">
<item name="text_field" xsi:type="array">
<item name="component" xsi:type="string">Magento_Ui/js/form/element/abstract</item>
<item name="config" xsi:type="array">
<!-- customScope is used to group elements within a single form (e.g. they can be validated separately) -->
<item name="customScope" xsi:type="string">customCheckoutForm</item>
<item name="template" xsi:type="string">ui/form/field</item>
<item name="elementTmpl" xsi:type="string">ui/form/element/input</item>
</item>
<item name="provider" xsi:type="string">checkoutProvider</item>
<item name="dataScope" xsi:type="string">customCheckoutForm.text_field</item>
<item name="label" xsi:type="string">Text Field</item>
<item name="sortOrder" xsi:type="string">1</item>
<item name="validation" xsi:type="array">
<item name="required-entry" xsi:type="string">true</item>
</item>
</item>
<item name="checkbox_field" xsi:type="array">
<item name="component" xsi:type="string">Magento_Ui/js/form/element/boolean</item>
<item name="config" xsi:type="array">
<!--customScope is used to group elements within a single form (e.g. they can be validated separately)-->
<item name="customScope" xsi:type="string">customCheckoutForm</item>
<item name="template" xsi:type="string">ui/form/field</item>
<item name="elementTmpl" xsi:type="string">ui/form/element/checkbox</item>
</item>
<item name="provider" xsi:type="string">checkoutProvider</item>
<item name="dataScope" xsi:type="string">customCheckoutForm.checkbox_field</item>
<item name="label" xsi:type="string">Checkbox Field</item>
<item name="sortOrder" xsi:type="string">3</item>
</item>
<item name="select_field" xsi:type="array">
<item name="component" xsi:type="string">Magento_Ui/js/form/element/select</item>
<item name="config" xsi:type="array">
<!--customScope is used to group elements within a single form (e.g. they can be validated separately)-->
<item name="customScope" xsi:type="string">customCheckoutForm</item>
<item name="template" xsi:type="string">ui/form/field</item>
<item name="elementTmpl" xsi:type="string">ui/form/element/select</item>
</item>
<item name="options" xsi:type="array">
<item name="0" xsi:type="array">
<item name="label" xsi:type="string">Please select value</item>
<item name="value" xsi:type="string"></item>
</item>
<item name="1" xsi:type="array">
<item name="label" xsi:type="string">Value 1</item>
<item name="value" xsi:type="string">value_1</item>
</item>
<item name="2" xsi:type="array">
<item name="label" xsi:type="string">Value 2</item>
<item name="value" xsi:type="string">value_2</item>
</item>
</item>
<!-- value element allows to specify default value of the form field -->
<item name="value" xsi:type="string">value_2</item>
<item name="provider" xsi:type="string">checkoutProvider</item>
<item name="dataScope" xsi:type="string">customCheckoutForm.select_field</item>
<item name="label" xsi:type="string">Select Field</item>
<item name="sortOrder" xsi:type="string">2</item>
</item>
<item name="date_field" xsi:type="array">
<item name="component" xsi:type="string">Magento_Ui/js/form/element/date</item>
<item name="config" xsi:type="array">
<!--customScope is used to group elements within a single form (e.g. they can be validated separately)-->
<item name="customScope" xsi:type="string">customCheckoutForm</item>
<item name="template" xsi:type="string">ui/form/field</item>
<item name="elementTmpl" xsi:type="string">ui/form/element/date</item>
</item>
<item name="provider" xsi:type="string">checkoutProvider</item>
<item name="dataScope" xsi:type="string">customCheckoutForm.date_field</item>
<item name="label" xsi:type="string">Date Field</item>
<item name="validation" xsi:type="array">
<item name="required-entry" xsi:type="string">true</item>
</item>
</item>
</item>
</item>
</item>
</item>
Hope this helps.
**Note:** Use the extension https://www.fmeextensions.com/custom-checkout-fields-order-attributes-extension-magento-2.html to get it done effortlessly.