System Methods or System Properties?

A lot of commonly used JADE constructs are properties, but there are a lot that are methods. Methods have to do some work to generate the return value, so they are sometimes significantly slower than properties.

Examples of commonly used methods are:

• Class .instances.size

  The size method loops through the object index (part of the database infrastructure), counting the entries. Unlike JADE collections, which maintain a count in the header, the virtual collection returned in the Class::instances property does not have such a count.

  The Class::countPersistentInstances method provides a faster way of obtaining the number of instances. You should use this method instead of the Class.instances.size method.

• Application ::formsCount

  This method counts the number of active forms.

• ListBox ::listCount

  This method counts the entries in a list box.

In many cases, the method can be called once and the result saved; for example, see "Iterating Through Arrays", earlier in this document, or the JADE documentation for ListBox::listCount in the JADE Encyclopaedia of Classes (Volume 3).