"""Translate strings to and from SOAP 1.2 XML name encoding

Implements rules for mapping application defined name to XML names
specified by the w3 SOAP working group for SOAP version 1.2 in
Appendix A of "SOAP Version 1.2 Part 2: Adjuncts", W3C Working Draft
17, December 2001, <http://www.w3.org/TR/soap12-part2/#namemap>

Also see <http://www.w3.org/2000/xp/Group/xmlp-issues>.

Author: Gregory R. Warnes <Gregory.R.Warnes@Pfizer.com>
Date::  2002-04-25
Version 0.9.0

"""

ident = "$Id$"

from re import *


def _NCNameChar(x):
    return x.isalpha() or x.isdigit() or x=="." or x=='-' or x=="_" 


def _NCNameStartChar(x):
    return x.isalpha() or x=="_" 


def _toUnicodeHex(x):
    hexval = hex(ord(x[0]))[2:]
    hexlen = len(hexval)
    # Make hexval have either 4 or 8 digits by prepending 0's
    if   (hexlen==1): hexval = "000" + hexval
    elif (hexlen==2): hexval = "00"  + hexval
    elif (hexlen==3): hexval = "0"   + hexval
    elif (hexlen==4): hexval = ""    + hexval
    elif (hexlen==5): hexval = "000" + hexval
    elif (hexlen==6): hexval = "00"  + hexval
    elif (hexlen==7): hexval = "0"   + hexval
    elif (hexlen==8): hexval = ""    + hexval    
    else: raise Exception, "Illegal Value returned from hex(ord(x))"
    
    return "_x"+ hexval + "_"


def _fromUnicodeHex(x):
    return eval( r'u"\u'+x[2:-1]+'"' ) 


def toXMLname(string):
    """Convert string to a XML name."""
    if string.find(':') != -1 :
        (prefix, localname) = string.split(':',1)
    else:
        prefix = None
        localname = string
    
    T = unicode(localname)

    N = len(localname)
    X = [];
    for i in range(N) :
        if i< N-1 and T[i]==u'_' and T[i+1]==u'x':
            X.append(u'_x005F_')
        elif i==0 and N >= 3 and \
                 ( T[0]==u'x' or T[0]==u'X' ) and \
                 ( T[1]==u'm' or T[1]==u'M' ) and \
                 ( T[2]==u'l' or T[2]==u'L' ):
            X.append(u'_xFFFF_' + T[0])
        elif (not _NCNameChar(T[i])) or (i==0 and not _NCNameStartChar(T[i])):
            X.append(_toUnicodeHex(T[i]))
        else:
            X.append(T[i])
    
    if prefix:
        return "%s:%s" % (prefix, u''.join(X))
    return u''.join(X)


def fromXMLname(string):
    """Convert XML name to unicode string."""

    retval = sub(r'_xFFFF_','', string )

    def fun( matchobj ):
        return _fromUnicodeHex( matchobj.group(0) )

    retval = sub(r'_x[0-9A-Za-z]+_', fun, retval )
        
    return retval