Fixing Unclear Stock Error Messages In Magento 2 Requisition Lists

Hey guys! Today, we're diving deep into a rather frustrating issue within Magento 2, specifically concerning the requisition list functionality and the unclear messages customers receive when facing stock problems. This can be a real headache, potentially costing you sales, so let's get right to it!

Understanding the Problem: Requisition List Stock Message Issue

When dealing with Magento 2, especially with the B2B extension, clear communication about stock availability is crucial. Imagine a customer diligently adding items to their requisition list, only to be met with a vague error message when they try to purchase. This is precisely the problem we're addressing.

This issue surfaces when a product has specific purchase quantity rules, for instance, it can only be bought in multiples of 10. Let’s say a customer tries to order 51 units. Magento 2's inventory management kicks in, but instead of providing a helpful message like “You can only buy this product in quantities of 10,” the customer sees a generic “The requested qty is not available” error. This unclear messaging leaves the customer confused and frustrated, potentially abandoning their purchase. It's like trying to decipher a cryptic code when all you want to do is buy something!

This issue stems from the Magento InventoryRequisitionList Plugin Model RequisitionListItem Validator StockPlugin::aroundValidate class. The original message doesn't adequately explain the problem, failing to inform the customer about the quantity restrictions. We need to ensure that Magento 2 provides a clear, actionable message, guiding the customer to adjust their order to comply with the quantity rules. This involves digging into the code and tweaking it to deliver the right message at the right time. We aim to avoid any potential sale losses by making the customer journey as smooth and intuitive as possible. This isn’t just about fixing a bug; it’s about enhancing the overall user experience and boosting customer satisfaction. We want our customers to feel supported and informed throughout their buying process, not left in the dark by ambiguous error messages.

Preconditions and Environment

Before we dive deeper, let's set the stage. This issue was observed under the following conditions:

• Magento/product-enterprise-edition 2.4.6-p1
• PHP 8.1
• Magento/extension-b2b 1.5.2-p1

These details are crucial because the behavior might differ in other environments or versions. Knowing the specific setup helps in replicating the issue and verifying the fix.

Steps to Reproduce

To see this in action, follow these steps:

1. Add a product to your requisition list that can only be purchased in specific quantities (e.g., multiples of 10).
2. In your customer view, attempt to order a quantity that doesn't meet the requirement (e.g., 51 units).
3. Observe the error message displayed.

Instead of the expected clear message, you'll likely encounter the generic “The requested qty is not available” message.

The Technical Deep Dive: Identifying the Root Cause

So, where exactly is this unclear message coming from? The culprit lies within the Magento InventoryRequisitionList Plugin Model RequisitionListItem Validator StockPlugin class. This class is responsible for validating the stock and quantity of items in the requisition list. Specifically, the aroundValidate method is the point of contention.

Within this method, Magento 2 checks if the requested quantity is salable. However, when the quantity doesn't align with the product's quantity rules, the error message generated is simply “The requested qty is not available.” This message, while technically accurate, is far from helpful for the customer. It doesn't explain why the quantity is unavailable or how to rectify the situation. It’s like a doctor telling you you're sick without explaining what's wrong or how to get better.

The core issue is that the system isn't leveraging the more descriptive error messages available within Magento 2's inventory management system. The Magento InventorySales Model IsProductSalableForRequestedQtyCondition IsCorrectQtyCondition::execute:116 class, for instance, generates a much clearer message: “You can buy this product only in quantities of %1 at a time.” This is the kind of customer-friendly message we want to display. To fix this, we need to tap into these more specific error messages and ensure they're displayed in the requisition list.

This involves modifying the StockPlugin to retrieve and display the detailed error messages provided by the inventory management system. Instead of just checking if the product is salable, we need to extract the specific reasons for unsalability and present them to the customer. This requires a bit of code surgery, but the result is a much smoother and more informative shopping experience for your customers. We're not just fixing a bug; we're enhancing the usability and clarity of the entire requisition list process.

The Solution: A Patch to the Rescue

To address this unclear message issue, a patch was developed. This patch modifies the Magento InventoryRequisitionList Plugin Model RequisitionListItem Validator StockPlugin.php file to provide more informative error messages. Let's break down the code changes:

Index: vendor/magento/module-inventory-requisition-list/Plugin/Model/RequisitionListItem/Validator/StockPlugin.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/vendor/magento/module-inventory-requisition-list/Plugin/Model/RequisitionListItem/Validator/StockPlugin.php b/vendor/magento/module-inventory-requisition-list/Plugin/Model/RequisitionListItem/Validator/StockPlugin.php
--- a/vendor/magento/module-inventory-requisition-list/Plugin/Model/RequisitionListItem/Validator/StockPlugin.php
+++ b/vendor/magento/module-inventory-requisition-list/Plugin/Model/RequisitionListItem/Validator/StockPlugin.php

@@ -115,7 +115,10 @@
         $result = $this->areProductsSalableForRequestedQty->execute([$request], $stockId);
         $result = current($result);
         if (!$result->isSalable() && !$product->isComposite()) {
-            $errors[$subject::ERROR_LOW_QUANTITY] = __('The requested qty is not available');
+            /** @var 
Magento
InventorySalesApi
Api
Data
ProductSalabilityErrorInterface $error */
+            foreach ($result->getErrors() as $error) {
+                $errors[$error->getCode()] = __($error->getMessage());
+            };
             return $errors;
         }

This patch replaces the generic error message with a loop that iterates through the specific error messages returned by the inventory salability check. This ensures that the customer receives a clear and precise message, such as “You can buy this product only in quantities of %1 at a time,” rather than the vague “The requested qty is not available.”

Here's a breakdown of the key changes:

• Iterating Through Errors: The patch introduces a foreach loop to process each error message returned by the $result->getErrors() method.
• Accessing Error Details: Inside the loop, it accesses the error code and message using $error->getCode() and $error->getMessage().
• Displaying Specific Messages: The error message is then displayed to the customer using __($error->getMessage()), ensuring it's properly translated and presented in a user-friendly format.

By implementing this patch, we're not just fixing a bug; we're significantly improving the customer experience. Customers will now understand why their order couldn't be placed and how to correct it, leading to fewer abandoned carts and increased sales. It's a small change with a big impact.

Expected vs. Actual Result: Clarity Wins

The Expected Result:

After applying the patch, we anticipate that customers attempting to order a quantity that violates the product's quantity rules will see a clear and informative message. For instance, if a product can only be bought in multiples of 10, and the customer tries to order 51, they should see the message: