Add Customer Grid Condition in Sales Rule and Validate Coupon for Selected Customers

I am working on a custom module for Magento 2.4.5 that extends the Sales Rule Conditions functionality. My goal is to:

1. Add a new condition to the “Conditions” tab in the Cart Price Rule section.
2. When the new condition is selected, it should display a Customer Grid (not a dropdown/select box) to allow selecting multiple customers.
3. Save the selected customer IDs as part of the condition’s data.
4. Validate the coupon on the frontend to ensure it applies only if the logged-in customer matches one of the selected customer IDs.

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What I’ve Done So Far:

1. Created a custom module structure.
2. Successfully added a custom condition to the Sales Rule Conditions section.
3. Managed to add a customer selection, but currently, I can only display a dropdown/select input instead of a full customer grid.

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The Problem:

• I want to render a customer grid instead of a dropdown/select box when my custom condition is selected.
• The customer grid should allow multiple selections, and the selected customer IDs should be saved.
• On the frontend, I need to validate the coupon for the logged-in customer against these selected customer IDs.

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My Questions:

1. How can I render a customer grid instead of a simple select box in the custom condition UI?
2. How can I pass the selected customer IDs and save them properly in the Sales Rule condition data?
3. How do I validate on the frontend (during cart rule checks) to ensure the coupon applies only if the customer matches one of the selected IDs?

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Code So Far:

Here’s the code snippet where I’ve added the custom condition:

CustomCondition.php

namespace VendorModuleModelRuleCondition;

use MagentoRuleModelConditionAbstractCondition;

class CustomerCondition extends AbstractCondition
{
    public function loadAttributeOptions()
    {
        $attributes = [
            'selected_customers' => __('Specific Customers')
        ];

        $this->setAttributeOption($attributes);
        return $this;
    }

    public function getInputType()
    {
        return 'multiselect'; // This is where I want to render a grid instead
    }

    public function getValueElementType()
    {
        return 'select'; // This should trigger a grid instead of a dropdown
    }

    public function validate(MagentoFrameworkModelAbstractModel $model)
    {
        // Frontend validation logic
        $customerId = $model->getCustomerId(); // Get the logged-in customer ID
        $selectedCustomerIds = explode(',', $this->getValue()); // Saved customer IDs

        return in_array($customerId, $selectedCustomerIds);
    }
}

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What I’m Stuck On:

• I don’t know how to replace the select input with a customer grid that allows multiple selections.
• I need guidance on saving the customer IDs and validating them correctly.

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Environment:

• Magento 2.4.5
• PHP 8.1

Any help, code examples, or suggestions on how to render the grid and save/validate the selected customer IDs would be greatly appreciated!