The remove operator lets you unlink a known object from a collection or association in an OCL executable action, for developers who need to change an association rather than produce a filtered result.

Syntax

Collection.remove(itemToRemove)

Part	Meaning
Collection	The collection or association from which you want to remove an object. For example, vCurrent_Customer.Orders.
itemToRemove	The specific object to unlink from that collection. For example, an Order held in the variable x.

What remove changes

remove is an Executable Action Language (EAL) command. It changes the actual association or collection on which you call it.

For example, when you evaluate:

vCurrent_Customer.Orders.remove(x)

MDriven removes the link between vCurrent_Customer and the order represented by x. The Order object is not deleted; it is no longer included in that customer's Orders association.

This differs from excluding, which returns a collection with an item left out but does not modify the underlying association.

Remove selected orders from a customer

Use remove when a user has selected existing objects and you want to unlink each selected object from the current object's association.

Assume that:

• vCurrent_Customer is the current customer.
• vSelected_Orders contains the orders selected in the user interface.
• vCurrent_Customer.Orders is the association to update.

Evaluate the following action:

vSelected_Orders->collect(x | vCurrent_Customer.Orders.remove(x))

The expression processes every selected order. For each order, represented by x, it calls remove on the current customer's Orders collection.

State	Result
Before the action	The customer is linked to five orders.
User selection	Two of those orders are present in vSelected_Orders.
After the action	The customer is linked to three orders.
Order objects	The two order objects still exist; only their links to this customer have been removed.

Choose the item by object, not position

Use remove when you have the object to unlink, such as a selected order stored in x. If you need to remove an item according to its numerical position in a collection, use removeAt instead. removeAt uses zero-based indexes, so index 0 identifies the first item.

See also

• removeAt
• OCL General Operators
• OCL Boolean Operators