LVOOP Programming Recommendations

• Naming conventions
  • Follow the C++ naming convention, e.g MyClass, myAttributeName, doSomething().
  • For classes use Prefix_ClassName
  • Use set_myAttributeName.vi and get_myAttributeName.vi for data access VIs.
  • Use following names for the dynamic class parameter: IN: ClassName in, OUT: ClassName out.
• Class
  • Add Description: Class responsibility, Author, History and copyright info. GPL is recommended.
  • Add Description also to ClassName.ctl .
  • Class wires: Select a remarkable wire type for ancestor classes.
  • Dynamic dispach VIs
    • You should indicate them with little open squares in the upper left and right corner.
    • You should add a hint to the VI description, e.g. This is a dynamic dispach VI.
  • Override VIs
    • You should indicate them with little open squares in the upper left and right corner.
    • You should add a hint to the VI description, e.g. This is an override VI.
• VIs
  • Connector Pane: Use 622226 (second from right in lower row). You can set the default in the LabVIEW.ini: defaultConPane=4834.
  • Add Desription to VI, controls and inidicators.
  • Supply reasonable icon.
  • Use labes of programming structures for inline documentation.
  • Check range of input and output parameters.
  • Check error
    • On entry
      Return reasonable output parameter values in case of error.
    • Class typecast
      Be aware that typecast returns a default object in case of error in = True . Make sure that you do not loose the original object.
  • VI Names
    • Attribute access: Use get_anAttribute.vi and set_anAttribute.vi
    • Boolean Status: isSomething.vi
    • Other: use a verb in the beginning of the name, e.g createObject.vi
• Inheritance
  LabVIEW supports single inheritance only and no interfaces. If you think in terms of multiple inheritance, you need to reconsider your design.
  • Use Composition or Aggregation instead of multiple inheritance. Refer to http://en.wikipedia.org/wiki/Class_diagram.
  • Use Delegation instead of interfaces. This pattern could also be useful to avoid code duplication.