How to disable an UI component field while add new item and enable while editing?

Question

Hi i'm new at magento 2 and i want to disable Ui Component field while creating item, and enable the field while editing.

Well, following this tutorial: Disabling a UI component field upon condition in Magento 2

The tutorial is the opposite of what i was looking out, it only works to Disable while editing and not while add. I want to disable while add, and enable while editing. example

DataProvider:

class DataProvider extends AbstractDataProvider

{ /** * @var ResourceModel\Data\Collection */ protected $collection;

/**
 * @var DataPersistorInterface
 */
protected $dataPersistor;
/**
 * @var array
 */
protected $loadedData;
/**
 * @param string $name
 * @param string $primaryFieldName
 * @param string $requestFieldName
 * @param CollectionFactory $pageCollectionFactory
 * @param DataPersistorInterface $dataPersistor
 * @param array $meta
 * @param array $data
 */
public function __construct(
 $name,
 $primaryFieldName,
 $requestFieldName,
 CollectionFactory $pageCollectionFactory,
 DataPersistorInterface $dataPersistor,
 array $meta = [],
 array $data = []
) {
 $this->collection = $pageCollectionFactory->create();
 $this->dataPersistor = $dataPersistor;
 $this->meta = $this->prepareMeta($this->meta);
 parent::__construct($name, $primaryFieldName, $requestFieldName, $meta, $data);
}
/**
 * Prepares Meta
 *
 * @param array $meta
 * @return array
 */
public function prepareMeta(array $meta)
{
 return $meta;
}
/**
 * Get data
 *
 * @return array
 */
public function getData()
{
 if (isset($this->loadedData)) {
 return $this->loadedData;
 }
 $items = $this->collection->getItems();
 foreach ($items as $page) {
 $this->loadedData[$page->getId()] = $page->getData();
 }
 $data = $this->dataPersistor->get('module_messages');
 if (!empty($data)) {
 $page = $this->collection->getNewEmptyItem();
 $page->setData($data);
 $this->loadedData[$page->getId()] = $page->getData();
 $this->dataPersistor->clear('module_messages');
 }
 if($_SESSION['action'] == 'edicao' AND isset($page)){
 $this->loadedData[$page->getId()]['do_we_hide_it'] = true;
 }
 return $this->loadedData;
}

}

form.xml

<field name="nome_header" formElement="input">
 <argument name="nmh" xsi:type="array">
 <item name="config" xsi:type="array">
 <item name="source" xsi:type="string">nmh</item>
 </item>
 </argument>
 <settings>
 <imports>
 <link name="disabled">${ $.provider}:data.edit</link>
 </imports>
 <validation>
 <rule name="required-entry" xsi:type="boolean">false</rule>
 </validation>
 <dataType>text</dataType>
 <label translate="true">Nome Header</label>
 <dataScope>nome_header</dataScope>
 </settings>
 </field>

• Afreen Sheikh: can you provide your code for data provider, it will be easy to help you then
• Rafael Fagundes: I put the code of DataProvider.php

Answer 1

1. you can do so just by checking if your Entity id exists In your data provider.

   public function getData()
   {
    if (!empty($this->loadedData)) {
    return $this->loadedData;
    }
    $items = $this->collection->getItems();
    foreach ($items as $page) {
    $rec = $page->getData();
    $rec['edit'] = true; // true when the data is set for edit form. it can be any variable name
    $this->loadedData[$page->getId()] = $rec;
    }
    return $this->loadedData;
   }
   

And then at your field in ui-component form check for the edit variable inside the imports tag

 <field name="to_hide_feild">
 <argument name="data" xsi:type="array">
 <item name="config" xsi:type="array">
 <item name="sortOrder" xsi:type="number">10</item>
 <item name="dataType" xsi:type="string">text</item>
 <item name="label" xsi:type="string" translate="true">Title</item>
 <item name="formElement" xsi:type="string">input</item>
 <item name="dataScope" xsi:type="string">title</item>
 <item name="validation" xsi:type="array">
 <item name="required-entry" xsi:type="boolean">true</item>
 </item>
 <item name="imports" xsi:type="array">
 <item name="disabled" xsi:type="string">${ $.provider}:data.edit</item>
 </item>
 </item>
 </argument>
 </field>

if someone is using different pattern for fields in ui-component then this code will work.

 <field name="nome_header" formElement="input">
 <argument name="data" xsi:type="array">
 <item name="config" xsi:type="array">
 <item name="source" xsi:type="string">customer</item>
 </item>
 </item>
 </argument>
 <settings>
 <imports>
 <link name="disabled">${ $.provider}:data.edit</link>
 </imports>
 <validation>
 <rule name="required-entry" xsi:type="boolean">false</rule>
 </validation>
 <dataType>text</dataType>
 <disabled>true</disabled>
 <label translate="true">Nome Header</label>
 <dataScope>data</dataScope>
 </settings>
 </field>

• Rafael Fagundes: It says that _loadedData is undefined.And when i add the line:$this->loadedData[$page->getId()]['do_we_hide_it'] = true; It says that $page is undefined.
• Afreen Sheikh: sorry it was a typing mistake. I fixed it. just remove '_' from loadData variable
• Rafael Fagundes: I got the conclusion that $page is only Defined when i edit and existing product. and its undefined when i try to create a new product.
• Afreen Sheikh: yes. there are no collections then so the foreach loop does not run.
• Rafael Fagundes: Ok, when i tried WITHOUT this line: $this->loadedData[$page->getId()]['do_we_hide_it'] = true; I doesn't shows any error, but don't disable any field. And When a tried WITH that line it says $page is undefined.