Drupal Commerce 2 - Create Simple Stock with ECA (Part 2)

In the previous story "Drupal Commerce 2 - Create Simple Stock with Custom Module and ECA", I created simple stock using custom module together with ECA module.  Later, I found that I can use just ECA to check availability of the product.  It's quite easy.  Here is what I do:

1. Start by create an integer field name field_eca_stock in Product Variation
2. Create a new ECA model as below:
   1. Event "Build Form" -> Restricted by entity type id "commerce_order_item"
   2. Condition : "Compare Two Scalar Value" 
      1. First value : [entity:purchased_entity:entity:field_eca_stock]
      2. Comparation Operator : Less than
      3. Second value : 1
   3. Action : Form Field: Set as Disable
      1. Field name : submit
      2. Set as disabled : yes

That's it.  

Software :

1. Drupal 10.3.2
2. ECA: Event - Condition – Action module 2.0.4