Types of Bindings (continued)
Accessor iterator: In a master-detail relationship, iterates over detail objects returned by accessors; created automatically if an accessor return from the Data Controls panel is dropped on the page. Accessor iterators are always related to a master iterator, which is the method iterator for the parent object. The accessor iterator returns the detail objects related to the current object in the master (or method) iterator.
Variable iterator: Iterates over local variables and method parameters created within the binding container. These variables and parameters are local to the binding container and exist only while the binding container object exists. When you use a Data Control method or operation that requires a parameter that is to be collected from the page, JDeveloper automatically defines a variable for the parameter in the page definition file. Attribute bindings can reference the binding container variables.
Value bindings are of different types depending on data, such as in the following examples:
A page has a drop-down list of department names. The combo box uses a list binding to display department names and update department numbers.
A form shows the employee’s last name as a text field. The text field uses an attribute binding to bind to the LastName attribute.
Action bindings, which are for a command component such as a button, provide access to methods or operations defined by the business object. For example, a Next button on a form navigates to the next record. The Next button uses an action binding to bind to the Next operation.