3.2. The Object Model

3.2. The Object Model
	Chapter 3. Configuration

The term 'object model' is used here to collectively refer to :-

the constraints that define a valid object hiearchy - i.e. which object(s) are valid child objects for a given parent object, how many siblings of the same type can exist etc.
for each object type, the allowable set of attributes, whether the attributes are mandatory or optional, their datatypes, and permissible values of those attributes

The bulk of this User Manual therefore serves to document the object model and how it controls operation of the FB2900.

Tip

This version of the User Manual may not yet be complete in its coverage of the full object model. Some more obscure attributes may not be covered at all - some of these may be attributes that are not used under any normal circumstances, and used only under guidance by support personnel. If you encounter attribute(s) that are not documented in this manual, please refer in the first instance to the documentation described in Section 3.2.1 below. If that information doesn't help you, and you think the attribute(s) may be relevant to implementing your requirements, please consult the usual support channel(s) for advice.

3.2.1. Formal definition of the object model

The object model has a formal definition in the form of an XML Schema Document (XSD) file, which is itself an XML file, normally intended for machine-processing. A more readable version of this information is available in Appendix M.

Note, however, that this is reference material, containing only brief descriptions, and intended for users who are familiar with the product, and in particular, for users configuring their units primarily via XML.

The XSD file is also available on the software downloads website by following the "XSD" link that is present against each software release.

3.2.2. Common attributes

Most objects have a comment attribute which is free-form text that can be used for any purpose. Similarly, most objects have a source attribute that is intended for use by automated configuration management tools. Neither of these attributes have a direct effect on the operation of the FB2900.

Many objects have a name attribute which is non optional and often needs to be unique within the list of object. This allows the named object to be referenced from other attributes. The data type for these is typically an NMTOKEN which is a variant of a string type that does not allow spaces. If you include spaces then they are removed automatically. This helps avoid any problems referencing names in other places especially where the reference may be a space separated list.

Many objects have a graph attribute. This allows a graph name to be specified. However, the actual graph name will be normalised to avoid spaces and limit the number of characters. Try to keep graph names as basic characters (letters, numbers) to avoid confusion.