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ID : 3557
Object
Overview of "Object"
An "object" described here is an "object" in object-oriented programming. This "object” is a software module which is consisted of a combination of an attribute data with an operation command for each operated target.
About detailed information of object-oriented programming, please refer to the programming language manual for VB (Visual Basic) and so on.
In Object-oriented programming, an attribute data is called Property, an operation command is called Method.
Difference Between an Object and a Normal Operation
Descriptions of a normal operation and an object are different as follows.
When writing an object, specify the target object first, then write a command or an attribute of the object.
| Types | Normal | Object |
|---|---|---|
| Operation | (Command) (Target name) | (Object name).(Command) |
| Reading a value | (Data name) | (Object name).(Attribute name) |
| Writing a value | (Data name) = (Value) | (Object name).(Attribute name) = (Value) |
When Operating
In a normal operation, operator needs to know which command can handle which target, or how to handle the target beforehand.
On the other hand, when operating objects, commands have been customized for each object. Therefore, operators only have to select desired command from the command list of each object.
When Writing or Reading Value
Since the value of data is written or read directly in a normal operation, operator needs to understand the data structure.
On the other hand, in the object, because an attribute name and value is handled in pair, operator is not required to know the data structure.
How to Use an Object
In general, it is necessary to create new object in advance so as to use an object. However,PacScript does not require creating new object because objects are registered in PacScript beforehand. An object that is no need of creation is called as an embedded object.
With regards to the type of embedded object, refer to "Embedded object".
Objects are also used in Provider. Provider is a system which enables to operate option boards and external devices in a shared interface.
For detailed information, refer to Provider Guide.
To use embedded objects, write as follows.
Operation
(Object name).(Command)
Reading a Value
(Object name).(Attribute name)
The following shows how to store the read-out value into a variable.
(Variable name to store a value)=(Object name).(Attribute name)
Writing a Value
(Object name).(Attribute name) = (Value)
Instead of specifying a value directory, a variable which stores value can be used.
ID : 3557