Understanding Automatic Dependency Information for Cascading Fixed-Choice Lists

Assume that you have defined two fixed-choice fields on the OrderLineItem objects named FulfillmentCenter and FulfillmentWarehouse. When defining the FulfillmentWarehouse field, further assume that you configured it to be constrained based on the value of the FulfillmentCenter field.

This combination allows the end-user to first pick a fulfillment center, then to pick an appropriate fulfillment warehouse related to that choice of fulfillment center. If the user changes the value of the fulfillment center, then the current value of the fulfillment warehouse is set to null to force the end-user to select an appropriate fulfillment warehouse based on the new value of the constraining FulfillmentCenter field. This type of cascading fixed-choice list dependency is automatically configured when you setup the "constrained by" field as part of defining the second fixed-choice field. In this example, the FulfilmentWarehouse field depends on the FulfillmentCenter field.

Next, assume that your application has the requirement to allow configuring the fulfillment warehouse only for line items with a quantity greater than five. To support this functionality, you would configure the following conditionally updateable expression on the FulfillmentWarehouse field:

Quantity_c > 5

After doing this, the Depends On multi-select list will appear in the Constraints section so you can configure the fact that your FulfillmentWarehouse now also depends on the Quantity field. After doing this, when the user changes the value of the quantity at runtime, this will dynamically affect whether the fulfillment warehouse field is updateable or not. The figure below shows the process of configuring the Quantity field as one on which the FulfillmentWarehouse field now depends. Notice that the Fulfillment Center field appears selected in the Depends On list, yet is disabled. This is because that dependency is required for the correct runtime functionality of the constrained fixed-choice fields and so you are not allowed to remove it.