ALPHA-VISION® Reference: Data Objects

Data Objects

SUMMARY

About Data Objects

CONTENTS

1. Data Objects
2. Modifying a User Defined Class
3. Jobs

Data Objects

• Data Objects are stored in files of the type Data Object List.
  
  
• Data Objects does only have the properties Name, Description and Station.
  
  
• Classes derivated from Data Objects may have additional attributes.
  
  
• Derivated classes may be fixed programmed or defined by stating a user defined Data Object Class in the Data Object List.
  
  
• Via user defined classes the type and number of Data Object Attributes are determined. These are either constants like name and description (numerical values are possible) or variables (e.g. value).

Modifying a User Defined Class

If a User Defined Class is modified after some objects were created with it, the already inputted values are resumed as fare as possible. Modifications of a Class become valid on storing the Class. (Just the same as with figures)

In that case the inputted values are kept. Numerical values are converted, whereby e.g. on converting from Float to Boolean only 0 or !=O is preserved, values different to Null or decimal places are lost.

Since the attributes on storing into a XML-File are identified by its name the values can’t be resumed in that case. But if the Data Object List, using the modified class is stored in memory (i.e. it is opened as a window), the existing values can be taken in.

In that case merely an attribute is added to the Data-Object; it is initialized with the default value.

In that case the values are lost. This is also true for adding a new attribute with the same name and the Data-Objects still in the memory.

Jobs

Executes the above described functions.

Behaves as the variable was a set point.