SAX2

Configuring XMLReader Behavior

A configuration mechanism was one of the key features added in the SAX2 release. Parsers can support extensible sets of named Boolean feature flags and property objects. These function in similar ways, including using URIs to identify any number of features and properties. The exception model, presented in Chapter 2 in Section 2.4.1 is used to distinguish the three basic types of feature or property: the current value may be read-only, read/write, or undefined. Some flags and properties may have rules about when they can be changed (typically not while parsing) or read.

Applications access property objects and feature flags through get*() and set*() methods and use URIs to identify the characteristic of interest. Since SAX does not provide a way to enumerate such URIs as supported by a parser, you will need to rely on parser documentation, or the tables in this section, to identify the legal identifiers. (Or consult the source code, if you have access to it.)

If you happen to be defining new handlers or features using the SAX2 framework, you don’t have to ask for permission to define new property or feature flag IDs. Since they are identified using URIs, just start your ID with a base URI that you control. (Only the SAX maintainers would start with the http://xml.org/sax/ URI, for example.) Typically, it will be easiest to make up some HTTP URL based on a fully qualified domain name that you control. As with namespace URIs, these are used ...