saxutils.py

Python Development Environment (Python IDE plugin for Eclipse). Features editor, code completion, re

        self._cont_handler.startDocument()

        # FIXME: what about char-stream?
        inf = source.getByteStream()
        buffer = inf.read(16384)
        while buffer != "":
            self.feed(buffer)
            buffer = inf.read(16384)

        self.close()
        self.reset()

        self._cont_handler.endDocument()

    def prepareParser(self, source):
        """This method is called by the parse implementation to allow
        the SAX 2.0 driver to prepare itself for parsing."""
        raise NotImplementedError("prepareParser must be overridden!")

# --- Utility functions

def prepare_input_source(source, base = ""):
    """This function takes an InputSource and an optional base URL and
    returns a fully resolved InputSource object ready for reading."""

    if type(source) in _StringTypes:
        source = xmlreader.InputSource(source)
    elif hasattr(source, "read"):
        f = source
        source = xmlreader.InputSource()
        source.setByteStream(f)
        if hasattr(f, "name"):
            source.setSystemId(f.name)

    if source.getByteStream() is None:
        sysid = source.getSystemId()
        if os.path.isfile(sysid):
            basehead = os.path.split(os.path.normpath(base))[0]
            source.setSystemId(os.path.join(basehead, sysid))
            f = open(sysid, "rb")
        else:
            source.setSystemId(urlparse.urljoin(base, sysid))
            f = urllib.urlopen(source.getSystemId())

        source.setByteStream(f)

    return source

# ===========================================================================
#
# DEPRECATED SAX 1.0 CLASSES
#
# ===========================================================================

# --- AttributeMap

class AttributeMap:
    """An implementation of AttributeList that takes an (attr,val) hash
    and uses it to implement the AttributeList interface."""

    def __init__(self, map):
        self.map=map

    def getLength(self):
        return len(self.map.keys())

    def getName(self, i):
        try:
            return self.map.keys()[i]
        except IndexError,e:
            return None

    def getType(self, i):
        return "CDATA"

    def getValue(self, i):
        try:
            if type(i)==types.IntType:
                return self.map[self.getName(i)]
            else:
                return self.map[i]
        except KeyError,e:
            return None

    def __len__(self):
        return len(self.map)

    def __getitem__(self, key):
        if type(key)==types.IntType:
            return self.map.keys()[key]
        else:
            return self.map[key]

    def items(self):
        return self.map.items()

    def keys(self):
        return self.map.keys()

    def has_key(self,key):
        return self.map.has_key(key)

    def get(self, key, alternative=None):
        return self.map.get(key, alternative)

    def copy(self):
        return AttributeMap(self.map.copy())

    def values(self):
        return self.map.values()

# --- Event broadcasting object

class EventBroadcaster:
    """Takes a list of objects and forwards any method calls received
    to all objects in the list. The attribute list holds the list and
    can freely be modified by clients."""

    class Event:
        "Helper objects that represent event methods."

        def __init__(self,list,name):
            self.list=list
            self.name=name

        def __call__(self,*rest):
            for obj in self.list:
                apply(getattr(obj,self.name), rest)

    def __init__(self,list):
        self.list=list

    def __getattr__(self,name):
        return self.Event(self.list,name)

    def __repr__(self):
        return "<EventBroadcaster instance at %d>" % id(self)

# --- ESIS document handler
import saxlib
class ESISDocHandler(saxlib.HandlerBase):
    "A SAX document handler that produces naive ESIS output."

    def __init__(self,writer=sys.stdout):
        self.writer=writer

    def processingInstruction (self,target, remainder):
        """Receive an event signalling that a processing instruction
        has been found."""
        self.writer.write("?"+target+" "+remainder+"\n")

    def startElement(self,name,amap):
        "Receive an event signalling the start of an element."
        self.writer.write("("+name+"\n")
        for a_name in amap.keys():
            self.writer.write("A"+a_name+" "+amap[a_name]+"\n")

    def endElement(self,name):
        "Receive an event signalling the end of an element."
        self.writer.write(")"+name+"\n")

    def characters(self,data,start_ix,length):
        "Receive an event signalling that character data has been found."
        self.writer.write("-"+data[start_ix:start_ix+length]+"\n")

# --- XML canonizer

class Canonizer(saxlib.HandlerBase):
    "A SAX document handler that produces canonized XML output."

    def __init__(self,writer=sys.stdout):
        self.elem_level=0
        self.writer=writer

    def processingInstruction (self,target, remainder):
        if not target=="xml":
            self.writer.write("<?"+target+" "+remainder+"?>")

    def startElement(self,name,amap):
        self.writer.write("<"+name)

        a_names=amap.keys()
        a_names.sort()

        for a_name in a_names:
            self.writer.write(" "+a_name+"=\"")
            self.write_data(amap[a_name])
            self.writer.write("\"")
        self.writer.write(">")
        self.elem_level=self.elem_level+1

    def endElement(self,name):
        self.writer.write("</"+name+">")
        self.elem_level=self.elem_level-1

    def ignorableWhitespace(self,data,start_ix,length):
        self.characters(data,start_ix,length)

    def characters(self,data,start_ix,length):
        if self.elem_level>0:
            self.write_data(data[start_ix:start_ix+length])

    def write_data(self,data):
        "Writes datachars to writer."
        data=string.replace(data,"&","&amp;")
        data=string.replace(data,"<","&lt;")
        data=string.replace(data,"\"","&quot;")
        data=string.replace(data,">","&gt;")
        data=string.replace(data,chr(9),"&#9;")
        data=string.replace(data,chr(10),"&#10;")
        data=string.replace(data,chr(13),"&#13;")
        self.writer.write(data)

# --- mllib

class mllib:
    """A re-implementation of the htmllib, sgmllib and xmllib interfaces as a
    SAX DocumentHandler."""

# Unsupported:
# - setnomoretags
# - setliteral
# - translate_references
# - handle_xml
# - handle_doctype
# - handle_charref
# - handle_entityref
# - handle_comment
# - handle_cdata
# - tag_attributes

    def __init__(self):
        self.reset()

    def reset(self):
        import saxexts # only used here
        self.parser=saxexts.XMLParserFactory.make_parser()
        self.handler=mllib.Handler(self.parser,self)
        self.handler.reset()

    def feed(self,data):
        self.parser.feed(data)

    def close(self):
        self.parser.close()

    def get_stack(self):
        return self.handler.get_stack()

    # --- Handler methods (to be overridden)

    def handle_starttag(self,name,method,atts):
        method(atts)

    def handle_endtag(self,name,method):
        method()

    def handle_data(self,data):
        pass

    def handle_proc(self,target,data):
        pass

    def unknown_starttag(self,name,atts):
        pass

    def unknown_endtag(self,name):
        pass

    def syntax_error(self,message):
        pass

    # --- The internal handler class

    class Handler(saxlib.DocumentHandler,saxlib.ErrorHandler):
        """An internal class to handle SAX events and translate them to mllib
        events."""

        def __init__(self,driver,handler):
            self.driver=driver
            self.driver.setDocumentHandler(self)
            self.driver.setErrorHandler(self)
            self.handler=handler
            self.reset()

        def get_stack(self):
            return self.stack

        def reset(self):
            self.stack=[]

        # --- DocumentHandler methods

        def characters(self, ch, start, length):
            self.handler.handle_data(ch[start:start+length])

        def endElement(self, name):
            if hasattr(self.handler,"end_"+name):
                self.handler.handle_endtag(name,
                                          getattr(self.handler,"end_"+name))
            else:
                self.handler.unknown_endtag(name)

            del self.stack[-1]

        def ignorableWhitespace(self, ch, start, length):
            self.handler.handle_data(ch[start:start+length])

        def processingInstruction(self, target, data):
            self.handler.handle_proc(target,data)

        def startElement(self, name, atts):
            self.stack.append(name)

            if hasattr(self.handler,"start_"+name):
                self.handler.handle_starttag(name,
                                            getattr(self.handler,
                                                    "start_"+name),
                                             atts)
            else:
                self.handler.unknown_starttag(name,atts)

        # --- ErrorHandler methods

        def error(self, exception):
            self.handler.syntax_error(str(exception))

        def fatalError(self, exception):
            raise RuntimeError(str(exception))