XML elements

To understand macro scripts you do not need to learn a great deal about XML, just the basics of the syntax. If your knowledge of XML syntax needs brushing up, you can learn more about it in XML syntax in the Z and I Emulator for Web macro language. However, almost all of what you need to know is covered in this subsection.

As you probably know already, an XML script consists of a collection of XML elements, some of which contain other XML elements, in much the same way that some HTML elements contain other HTML elements. However, unlike HTML, XML allows a program developer to define new XML elements that reflect the structure of the information that the developer wishes to store. The Z and I Emulator for Web macro language contains approximately 35 different types of XML elements for storing the information needed to describe a macro. This macro language is described at length in The macro language.

This book, when referring to an XML macro element, uses the element name enclosed in angle brackets. Examples: <HAScript> element, <screen> element.

Figure 1 shows an example of an XML element:

Figure 1. Sample XML element

<SampleElement attribute1="value1" attribute2="value2">
...
</SampleElement>

The <SampleElement> element shown in the figure above contains the key components of every macro element. The first line is the begin tag. It consists of a left angle bracket (<), followed by the name of the XML element (SampleElement), followed by attribute definitions, followed by a right angle bracket (>). The second line consists of an ellipsis (...) that is not part of XML syntax but is used in the figure above to indicate the possible presence of other elements inside the <SampleElement> element. The third line is the end tag. It contains the name of the element enclosed in angle brackets with a forward slash after the first angle bracket (</Sample Element>).

In the begin tag, the attributes are specified by using the attribute name (such as attribute1), followed by an equals sign (=), followed by an attribute value enclosed in quotation marks (such as "value1"). Any number of attributes can occur in the begin tag.

If the macro element does not contain other XML elements then it can be written in the shorthand fashion shown in Figure 2:

Figure 2. Sample XML element written in the shorthand format

<SampleElement attribute1="value1" attribute2="value2"  />

In the figure above the <SampleElement> element is written with a left angle bracket (<) followed by the name (SampleElement), followed by the attributes, followed by a forward slash and a right angle bracket (/>). Thus the entire XML element is written within a single pair of angle brackets.