How to populate data in custom filed in product edit form in Magento 2

Question

I have added custom filed dropdown in product edit form using UI component. Below is the code in file app/code/Vendor/Module/view/adminhtml/ui_component/product_form.xml

<?xml version="1.0" encoding="UTF-8"?>
<form xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Ui:etc/ui_configuration.xsd">
<field name="customer" component="Vendor_Module/js/components/select-customer" sortOrder="5" formElement="select">
 <argument name="data" xsi:type="array">
 <item name="config" xsi:type="array">
 <item name="filterOptions" xsi:type="boolean">true</item>
 <item name="multiple" xsi:type="boolean">false</item>
 <item name="showCheckbox" xsi:type="boolean">true</item>
 <item name="disableLabel" xsi:type="boolean">true</item>
 <item name="levelsVisibility" xsi:type="number">1</item>
 </item>
 </argument>
 <settings>
 <required>true</required>
 <validation>
 <rule name="required-entry" xsi:type="boolean">true</rule>
 </validation>
 <elementTmpl>ui/grid/filters/elements/ui-select</elementTmpl>
 <label translate="true">Select Customer</label>
 <dataScope>data.customer</dataScope>
 <componentType>field</componentType>
 <listens>
 <link name="${ $.namespace }.${ $.namespace }:responseData">setParsed</link>
 </listens>
 </settings>
 <formElements>
 <select>
 <settings>
 <options class="Vendor\Module\Ui\Component\Create\Form\Customer\Options"/>
 </settings>
 </select>
 </formElements>
 </field>
</form>

By this code, I'm able to display a drop-down with customer name and id like an option value

enter image description here

Now when someone edits the product, I want to preselect the drop-down value base on the data save in another table. Can anyone help me with this? I think using data provider one can achieve this but not sure

If i add a dataprovider using below tag. It is giving an error "Element 'dataSource': This element is not expected"

 <dataSource name="customfiled_customer_data_source">
 <argument name="dataProvider" xsi:type="configurableObject">
 <argument name="class" xsi:type="string">Vendor\Module\Ui\DataProvider\Product\CustomerDataProvider</argument>
 <argument name="name" xsi:type="string">customfiled_customer_data_source</argument>
 <argument name="primaryFieldName" xsi:type="string">brand_id</argument>
 <argument name="requestFieldName" xsi:type="string">customer</argument>
 </argument>
 <argument name="data" xsi:type="array">
 <item name="js_config" xsi:type="array">
 <item name="component" xsi:type="string">Magento_Ui/js/form/provider</item>
 </item>
 </argument>
 </dataSource>

Answer 1

 <field name="customer">
 <argument name="data" xsi:type="array">
 <item name="options" xsi:type="Vendor\Module\Ui\Component\Create\Form\Customer\Options</item>
 <item name="config" xsi:type="array">
 <item name="filterOptions" xsi:type="boolean">true</item>
 <item name="multiple" xsi:type="boolean">false</item>
 <item name="showCheckbox" xsi:type="boolean">true</item>
 <item name="disableLabel" xsi:type="boolean">true</item>
 <item name="levelsVisibility" xsi:type="number">1</item>
 <item name="dataScope" xsi:type="string">Column_name(which you 
 want from database)</item>
 </item>
 </argument>
 </field>

you can use datasource in form like below:

 <dataSource name="custom_form_data_source">
 <argument name="dataProvider" xsi:type="configurableObject">
 <argument name="class" xsi:type="string">Vendor\Namespace\Model\DataProvider</argument>
 <argument name="name" xsi:type="string">custom_form_data_source</argument>
 <argument name="primaryFieldName" xsi:type="string">id</argument>
 <argument name="requestFieldName" xsi:type="string">id</argument>
 <argument name="data" xsi:type="array">
 <item name="config" xsi:type="array">
 <item name="submit_url" xsi:type="url" path="*/*/save"/>
 </item>
 </argument>
 </argument>
 <argument name="data" xsi:type="array">
 <item name="js_config" xsi:type="array">
 <item name="component" 
 xsi:type="string">Magento_Ui/js/form/provider</item>
 </item>
 </argument>
</dataSource>

your form file should be like:

(Just demo code)

 <?xml version="1.0" encoding="UTF-8"?>
 <form xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Ui:etc/ui_configuration.xsd"> Namespace_imports_form.Namespace_custom_form_data_source Namespace_imports_form.Namespace_custom_form_data_source Import Namespace using CSV data Namespace_imports_form

 <item name="buttons" xsi:type="array">
 <item name="back" xsi:type="string">Vendor\Namespace\Block\Adminhtml\Edit\Imports\BackButton</item>
 <item name="reset" xsi:type="string">Vendor\Namespace\Block\Adminhtml\Edit\ResetButton</item>
 <item name="save" xsi:type="string">Vendor\Namespace\Block\Adminhtml\Edit\SaveButton</item>
 </item>
 <item name="layout" xsi:type="array">
 <item name="type" xsi:type="string">tabs</item>
 <item name="navContainerName" xsi:type="string">left</item>
 </item>
</argument>
<dataSource name="Namespace_custom_form_data_source">
 <argument name="dataProvider" xsi:type="configurableObject">
 <argument name="class" xsi:type="string">Vendor\Namespace\Model\DataProvider</argument>
 <argument name="name" xsi:type="string">Namespace_custom_form_data_source</argument>
 <argument name="primaryFieldName" xsi:type="string">Namespace_id</argument>
 <argument name="requestFieldName" xsi:type="string">id</argument>
 <argument name="data" xsi:type="array">
 <item name="config" xsi:type="array">
 <item name="submit_url" xsi:type="url" path="*/imports/save"/>
 </item>
 </argument>
 </argument>
 <argument name="data" xsi:type="array">
 <item name="js_config" xsi:type="array">
 <item name="component" xsi:type="string">Magento_Ui/js/form/provider</item>
 </item>
 </argument>
</dataSource>
<fieldset name="Namespace" sortOrder="5">
 <argument name="data" xsi:type="array">
 <item name="config" xsi:type="array">
 <item name="label" xsi:type="string">Item information</item>
 <item name="collapsible" xsi:type="boolean">false</item>
 </item>
 </argument>
 <field name="upload_file">
 <argument name="data" xsi:type="array">
 <item name="config" xsi:type="array">
 <item name="dataType" xsi:type="string">text</item>
 <item name="label" xsi:type="string" translate="true">Select File to Import </item>
 <item name="formElement" xsi:type="string">fileUploader</item>
 <item name="elementTmpl" xsi:type="string">ui/form/element/uploader/uploader</item>
 <item name="source" xsi:type="string">Namespace</item>
 <item name="validation" xsi:type="array">
 <item name="required-entry" xsi:type="boolean">true</item>
 </item>
 <item name="uploaderConfig" xsi:type="array">
 <item name="url" xsi:type="url" path="*/imports/imports"/>
 </item>
 </item>
 </argument>
 </field>
</fieldset>

• chirag dodia: This will not work because my data is stored in another custom table, not in catalog eav table.
• Rutvee Sojitra: Yes but you can join your custom table with catalog collection
• chirag dodia: That I understood but where I can define dataprovider class. If i add datasource tag in XML it is giving an error like "datasource element is not expected"
• Rutvee Sojitra: @chiragdodia yes you can use datasource like above code
• chirag dodia: Thank you for your effort @rutvee-sojitra But as I have mentioned above datadataSource tag not allowed in product edit form XML schema. The code you have mentioned is work when you add a form to your custom module.