Small snippet that will handle a in stock, low stock, and out of stock inventory settings

schema_availability_value_logic.xml

<mvt:comment>
Schema Value
</mvt:comment>
<mvt:assign name="l.settings:product:schema_inventory_message:value" value="''" />

<mvt:comment>
Schema Availability Values
</mvt:comment>
<mvt:assign name="l.settings:product:schema_inventory_message:discontinued" value="'Discontinued'" />
<mvt:assign name="l.settings:product:schema_inventory_message:in_stock" value="'InStock'" />
<mvt:assign name="l.settings:product:schema_inventory_message:in_store_only" value="'InStoreOnly'" />
<mvt:assign name="l.settings:product:schema_inventory_message:limited_availability" value="'LimitedAvailability'" />
<mvt:assign name="l.settings:product:schema_inventory_message:online_only" value="'OnlineOnly'" />
<mvt:assign name="l.settings:product:schema_inventory_message:out_of_stock" value="'OutOfStock'" />
<mvt:assign name="l.settings:product:schema_inventory_message:pre_order" value="'PreOrder'" />
<mvt:assign name="l.settings:product:schema_inventory_message:pre_sale" value="'PreSale'" />
<mvt:assign name="l.settings:product:schema_inventory_message:sold_out" value="'SoldOut'" />

<mvt:comment>
Product is in stock if client isn't tracking inventory
</mvt:comment>
<mvt:if expr="l.settings:product:inv_active EQ 0">
	<mvt:assign name="l.settings:product:schema_inventory_message:value" value="l.settings:product:schema_inventory_message:in_stock" />
<mvt:else>
	<mvt:comment>
	Product is tracking inventory
	</mvt:comment>

	<mvt:comment>
	Low Level
	</mvt:comment>
	<mvt:if expr="l.settings:product:inv_level EQ 'low'">
		<mvt:assign name="l.settings:product:schema_inventory_message:value" value="l.settings:product:schema_inventory_message:limited_availability" />
		<mvt:comment>
	Out Of Stock
	</mvt:comment>
	<mvt:elseif expr="l.settings:product:inv_level EQ 'out'">
		<mvt:assign name="l.settings:product:schema_inventory_message:value" value="l.settings:product:schema_inventory_message:out_of_stock" />
	<mvt:else>
		<mvt:comment>
		In Stock
		</mvt:comment>
		<mvt:assign name="l.settings:product:schema_inventory_message:value" value="l.settings:product:schema_inventory_message:in_stock" />
	</mvt:if>
</mvt:if>