Array Collection (PRIM_ACOL)

Sequential collection of objects accessible via an index

Ancestors - Collection (PRIM_COLL) Object (PRIM_OBJT)

Details

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.

Array collections and List collections are very similar in nature, the only real difference being the way they handle memory allocation in Windows.

Examples

Defining an array collection. This collection stores instances of a user defined customer data object.

     Define_Com Class(#Prim_Acol<#Customer>) Name(#Customers)

Collection items can be created by assigning them to an existing reference or creating a new one as below.

     #Customers.Insert((*New #Customer))

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

Properties

Name	Description
AllowsDuplicates	AllowsDuplicates indicates whether the collection allows duplicates Inherited from Collection (PRIM_COLL)
Collects	The class of object to be collected
ComponentClassName	ComponentClassName is the name of the component's class. Inherited from Object (PRIM_OBJT)
ComponentMembers	ComponentMembers provides access to all the member components of this component Inherited from Object (PRIM_OBJT)
ComponentPatternName	ComponentPatternName is used to qualify the class of the component. Inherited from Object (PRIM_OBJT)
ComponentTag	Generic space allowing a value to be stored for the instance Inherited from Object (PRIM_OBJT)
ComponentType	ComponentType gives you access to the type information about the component Inherited from Object (PRIM_OBJT)
ComponentTypeName	ComponentTypeName is the fully qualified name of the component's class. Inherited from Object (PRIM_OBJT)
First	Reference to the first item in the collection
IndexOf	IndexOf returns the index number of an item in a collection
IsEmpty	IsEmpty indicates whether the collection contains any items. Inherited from Collection (PRIM_COLL)
IsOrdered	IsOrdered indicates whether the collection is ordered. Inherited from Collection (PRIM_COLL)
Item	Allows access to a specific item in the collection
ItemCount	ItemCount is the number of items in a collection Inherited from Collection (PRIM_COLL)
Last	Last is the Last item in a collection
Name	Name identifies the component Inherited from Object (PRIM_OBJT)
Owner	Owner owns this component Inherited from Object (PRIM_OBJT)
Parent	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)

Events

Name

Description

CreateInstance

CreateInstance is signalled when an instance of a component is created Inherited from Object (PRIM_OBJT)

DestroyInstance

DestroyInstance is signalled when an instance of a component is about to be destroyed Inherited from Object (PRIM_OBJT)

IsEqual

Fired whenever the collection needs to compare two items

Object, Subject, Equal

Methods

Name	Description
CalculateHash	CalculateHash calculates a hash value Inherited from Collection (PRIM_COLL) Result, Value
Contains	Does the supplied instance exist in the collection? Result, Object
CreateAccessor	CreateAccessor creates an accessor component that provides read-only access to the collection Result
CreateIterator	CreateIterator method creates an iterator component that enables iteration through the collection Result
Insert	Insert adds an item to a collection Item
InsertAfter	InsertAfter adds an item to a collection after a specified position Item, Index
InsertBefore	InsertBefore adds an item to a collection before a specified item Item, Index
InsertFirst	InsertFirst adds an item in the beginning of the collection Item
InsertLast	InsertLast adds an item in the end of the collection Item
OccurrencesOf	Find the number of occurrences of an instance in the collection Result, Object
Remove	Remove method removes an item Result, Object
RemoveAll	RemoveAll removes all items in the collection
RemoveAt	Removes the item at the specified position Result, Index
RemoveFirst	Remove the first item from the collection Result
RemoveLast	Remove the last item from the collection Result
ReplaceAt	Replace the instance at the specified position with a different object Result, Item, Index

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