Here is way to set value & make field readonly(disabled)
Override
vendor/magento/module-checkout/view/frontend/layout/checkout_index_index.xml to app/design/frontend/package/themename/Magento_Checkout/layout/checkout_index_index.xml
<?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="shipping-address-fieldset" xsi:type="array">
<item name="children" xsi:type="array">
<item name="company" xsi:type="array">
<item name="visible" xsi:type="boolean">false</item>
</item>
<item name="city" xsi:type="array">
<item name="disabled" xsi:type="string">disabled</item>
<item name="value" xsi:type="string">Value</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</item>
</argument>
</arguments>
</referenceBlock>
</body>
</page>
In above file i added,
<item name="company" xsi:type="array">
<item name="visible" xsi:type="boolean">false</item>
</item>
<item name="city" xsi:type="array">
<item name="disabled" xsi:type="string">disabled</item>
<item name="value" xsi:type="string">value</item>
</item>
Then Override,
\Magento\Checkout\Block\Checkout\AttributeMerger to Namespace\Modulename\Block\Checkout\AttributeMerger
/**
* Copyright © 2016 Magento. All rights reserved.
* See COPYING.txt for license details.
*/
namespace Namespace\Modulename\Block\Checkout;
class AttributeMerger extends \Magento\Checkout\Block\Checkout\AttributeMerger
{
public function __construct(
\Magento\Customer\Helper\Address $addressHelper,
\Magento\Customer\Model\Session $customerSession,
\Magento\Customer\Api\CustomerRepositoryInterface $customerRepository,
\Magento\Directory\Helper\Data $directoryHelper
) {
parent::__construct(
$addressHelper,
$customerSession,
$customerRepository,
$directoryHelper
);
}
/**
* Retrieve UI field configuration for given attribute
*
* @param string $attributeCode
* @param array $attributeConfig
* @param array $additionalConfig field configuration provided via layout XML
* @param string $providerName name of the storage container used by UI component
* @param string $dataScopePrefix
* @return array
* @SuppressWarnings(PHPMD.CyclomaticComplexity)
* @SuppressWarnings(PHPMD.NPathComplexity)
*/
protected function getFieldConfig(
$attributeCode,
array $attributeConfig,
array $additionalConfig,
$providerName,
$dataScopePrefix
) {
// street attribute is unique in terms of configuration, so it has its own configuration builder
if (isset($attributeConfig['validation']['input_validation'])) {
$validationRule = $attributeConfig['validation']['input_validation'];
$attributeConfig['validation'][$this->inputValidationMap[$validationRule]] = true;
unset($attributeConfig['validation']['input_validation']);
}
if ($attributeConfig['formElement'] == 'multiline') {
return $this->getMultilineFieldConfig($attributeCode, $attributeConfig, $providerName, $dataScopePrefix);
}
$uiComponent = isset($this->formElementMap[$attributeConfig['formElement']])
? $this->formElementMap[$attributeConfig['formElement']]
: 'Magento_Ui/js/form/element/abstract';
$elementTemplate = isset($this->templateMap[$attributeConfig['formElement']])
? 'ui/form/element/' . $this->templateMap[$attributeConfig['formElement']]
: 'ui/form/element/' . $attributeConfig['formElement'];
$element = [
'component' => isset($additionalConfig['component']) ? $additionalConfig['component'] : $uiComponent,
'config' => [
// customScope is used to group elements within a single form (e.g. they can be validated separately)
'customScope' => $dataScopePrefix,
'customEntry' => isset($additionalConfig['config']['customEntry'])
? $additionalConfig['config']['customEntry']
: null,
'template' => 'ui/form/field',
'elementTmpl' => isset($additionalConfig['config']['elementTmpl'])
? $additionalConfig['config']['elementTmpl']
: $elementTemplate,
'tooltip' => isset($additionalConfig['config']['tooltip'])
? $additionalConfig['config']['tooltip']
: null
],
'dataScope' => $dataScopePrefix . '.' . $attributeCode,
'label' => $attributeConfig['label'],
'provider' => $providerName,
'sortOrder' => isset($additionalConfig['sortOrder'])
? $additionalConfig['sortOrder']
: $attributeConfig['sortOrder'],
'validation' => $this->mergeConfigurationNode('validation', $additionalConfig, $attributeConfig),
'options' => $this->getFieldOptions($attributeCode, $attributeConfig),
'filterBy' => isset($additionalConfig['filterBy']) ? $additionalConfig['filterBy'] : null,
'customEntry' => isset($additionalConfig['customEntry']) ? $additionalConfig['customEntry'] : null,
'visible' => isset($additionalConfig['visible']) ? $additionalConfig['visible'] : true,
];
if (isset($additionalConfig['disabled']) && $additionalConfig['disabled'] != null) {
$element['disabled'] = "disabled";
}
if (isset($additionalConfig['value']) && $additionalConfig['value'] != null) {
$element['value'] = "";
}
if (isset($attributeConfig['value']) && $attributeConfig['value'] != null) {
$element['value'] = $attributeConfig['value'];
} elseif (isset($attributeConfig['default']) && $attributeConfig['default'] != null) {
$element['value'] = $attributeConfig['default'];
} else {
$defaultValue = $this->getDefaultValue($attributeCode);
if (null !== $defaultValue) {
$element['value'] = $defaultValue;
}
}
return $element;
}
/**
* @param string $attributeCode
* @return null|string
*/
protected function getDefaultValue($attributeCode)
{
switch ($attributeCode) {
case 'firstname':
if ($this->getCustomer()) {
return $this->getCustomer()->getFirstname();
}
break;
case 'lastname':
if ($this->getCustomer()) {
return $this->getCustomer()->getLastname();
}
break;
case 'country_id':
return $this->directoryHelper->getDefaultCountry();
break;
case 'city':
if ($this->getCustomer()) {
return "return your value"
}
}
return null;
}
}
In Above file i added below code in function getFieldConfig
if (isset($additionalConfig['disabled']) && $additionalConfig['disabled'] != null) {
$element['disabled'] = "disabled";
}
And added below code in function getDefaultValue
case 'city':
if ($this->getCustomer()) {
return "return your value";
}
Thanks !!
Best Answer
To either make the State option MANDATORY or OPTIONAL, as of Magento 2.2.x, you set the option at: STORES>>Configuration>>General>>State Options