The descriptors

Each type of descriptor is stored as an individual XML element situated within the <description> element of one macro screen.

You do not have to understand all the types of descriptors at first. Instead you should begin by becoming familiar with just the following types:

The OIA descriptor
The Number of Fields descriptor
The Number of Input Fields descriptor
The String descriptor

These types of descriptors are sufficient to reliably describe many and perhaps even most application screens. However, if these types are not sufficient, then you should turn for help to one of the other types of descriptors.

Table 1 lists all the types of descriptors and shows the number of descriptors of each type that are allowed to exist in one macro screen (more specifically, in one <description> element belonging to one <screen> element):

Table 1. Types of descriptors, how many of each type allowed
Type of descriptor:	Number of this type of descriptor allowed per macro screen:
OIA	1 (required)
Number of Fields	0 or 1
Number of Input Fields	0 or 1
String descriptor	0 or more
Cursor descriptor	0 or 1
Attribute descriptor	0 or more
Condition descriptor	0 or more
Custom descriptor	0 or more

The following subsections describe each type of descriptor in detail.