vrml.protofunctions

Functions for manipulating prototypes (node classes)

Prototypes are implemented as classes, and so are available from every instance node, but we often want to be able to manipulate the classes themselves without needing lots of class-methods

The protofunctions module allows us to abstract the actual implementation of the prototype away. If we at some point want to create a real "prototype" class, we could do so with most changes confined to this module.

Functions

_getcls( cls )

Utility function returns class when passed instance or class

addField( cls , field )

Add a particular field/event to the class/prototype definition

At present this just calls setattr(cls,field.name,field)

builtin( cls )

Return whether the class is "built-in" to the system

defName( obj , value = None , * args , ** named )

Get/set the VRML97 defName for the object

delExternalURL( cls )

Delete the externproto URL associated with a prototype

delSceneGraph( cls )

Delete the scenegraph associated with a prototype

getExternalURL( cls )

Get the externproto URL associated with a prototype (or [])

getField( cls , field )

Get a field/event object for the given name

field: a field-name specifier, which may be any of the following, (with the various options checked in order, so that earlier options will take precedence over later options):

the exact name of the field/demand as specified in the class's namespace (fastest and first checked)
the "storage" name of a field, that is, the "name" attribute of a field where that name does not match the previous definition (commonly seen in non-standard fields on VRML97 standard nodes)
the "storage" name of an event
a pseudo-event with the prefix "set_" or the suffix "_changed", which will return the associated field/event as if the suffix were not present (does a recursive call with the truncated name)