XML (version 3.1-1)

makeClassTemplate: Create S4 class definition based on XML node(s)

Description

This function is used to create an S4 class definition by examining an XML node and mapping the sub-elements to S4 classes. This works very simply with child nodes being mapped to other S4 classes that are defined recursively in the same manner. Simple text elements are mapped to a generic character string. Types can be mapped to more specific types (e.g. boolean, Date, integer) by the caller (via the types) parameter. The function also generates a coercion method from an XMLAbstractNode to an instance of this new class.

This function can either return the code that defines the class or it can define the new class in the R session.

Usage

makeClassTemplate(xnode, types = character(), default = "ANY",
                   className = xmlName(xnode), where = globalenv())

Value

• A list with 4 elements:
• name
  the name of the new class
• slots
  a character vector giving the slot name and type name pairs
• def
  code for defining the class
• coerce
  code for defining the coercion method from an XMLAbstractNode to an instance of the new class
• If where is not NULL, the class and coercion code is actually evaluated and the class and method will be defined in the R session as a side effect.

concept

• reflection
• meta-programming

See Also

xmlToS4