Sorted collection of components accessible by index
Sorted Array collections are a dynamically sized, ordered collection of components. The features of the Array component are positional in nature, in reference to a given index or to the beginning or end of the list. Indexing is always relative to 1. When an item is added to the collection, the Compare event is fired as often as required to allow a user defined sort to be evaulated.
Defining a sorted array collection. This collection stores instances of a user defined customer data object.
Define_Com Class(#Prim_SACO<#Customer>) Name(#Customers)
Collection items can be created by assigning them to an existing reference or creating a new one as below.
Collection items can be accessed by their position in the collection.
#Customers<123>.CustomerName := #CustomerName
All collection items can be addressed as follows. Here, all the customers in the collection are having a property value incremented.
#Customers<>.CreditLimit += 1000
The FOR command can also be used to iterate over the collection contents. The items will be returned in the order they are stored in the collection.
For each(#Customer) in (#Customers) ... Endfor
To monitor for an event from any instance in the collection, <> can be appended to an EVTROUTINE. The COM_SENDER parameter will provide access to the instance firing the event. In this example, a changed event on the customer instances is monitored.
Evtroutine Handling(#Customers<>.Changed) Com_Sender(#Sender) #Com_owner.AddEvent(("&1 changed").Substitute(#Sender.CustomerName)) Endroutine
|AllowsDuplicates indicates whether the collection allows duplicates Inherited from Collection (PRIM_COLL)
|The class of object to be collected
|ComponentClassName is the name of the component's class. Inherited from Object (PRIM_OBJT)
|ComponentMembers provides access to all the member components of this component Inherited from Object (PRIM_OBJT)
|ComponentPatternName is used to qualify the class of the component. Inherited from Object (PRIM_OBJT)
|Generic space allowing a value to be stored for the instance Inherited from Object (PRIM_OBJT)
|ComponentType gives you access to the type information about the component Inherited from Object (PRIM_OBJT)
|ComponentTypeName is the fully qualified name of the component's class. Inherited from Object (PRIM_OBJT)
|Reference to the first item in the collection
|IndexOf returns the index number of an item in a collection
|IsEmpty indicates whether the collection contains any items. Inherited from Collection (PRIM_COLL)
|IsOrdered indicates whether the collection is ordered. Inherited from Collection (PRIM_COLL)
|Provides access to a particular item in a collection
|ItemCount is the number of items in a collection Inherited from Collection (PRIM_COLL)
|Last is the Last item in a collection
|Name identifies the component Inherited from Object (PRIM_OBJT)
|Owner owns this component Inherited from Object (PRIM_OBJT)
|The component instance to which this instance is attached. The visual container for a control or the collector of a set of child instances Inherited from Object (PRIM_OBJT)
|Compare is triggered when two key components need to be compared
Object, Subject, Result
|CreateInstance is signalled when an instance of a component is created Inherited from Object (PRIM_OBJT)
|DestroyInstance is signalled when an instance of a component is about to be destroyed Inherited from Object (PRIM_OBJT)
|CalculateHash calculates a hash value Inherited from Collection (PRIM_COLL)
|Does the supplied instance exist in the collection?
|CreateAccessor creates an accessor component that provides read-only access to the collection
|CreateIterator method creates an iterator component that enables iteration through the collection
|Insert adds an item to a collection
|Find the number of occurrences of an instance in the collection
|Remove method removes an item
|RemoveAll removes all items in the collection
|Removes the item at the specified position
|Remove the first item from the collection
|Remove the last item from the collection
LANSA Version 15, April 2020