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Editing: _xmlgen.py
""" module for generating and serializing xml and html structures by using simple python objects. (c) holger krekel, holger at merlinux eu. 2009 """ import sys, re if sys.version_info >= (3,0): def u(s): return s def unicode(x, errors=None): if hasattr(x, '__unicode__'): return x.__unicode__() return str(x) else: def u(s): return unicode(s) unicode = unicode class NamespaceMetaclass(type): def __getattr__(self, name): if name[:1] == '_': raise AttributeError(name) if self == Namespace: raise ValueError("Namespace class is abstract") tagspec = self.__tagspec__ if tagspec is not None and name not in tagspec: raise AttributeError(name) classattr = {} if self.__stickyname__: classattr['xmlname'] = name cls = type(name, (self.__tagclass__,), classattr) setattr(self, name, cls) return cls class Tag(list): class Attr(object): def __init__(self, **kwargs): self.__dict__.update(kwargs) def __init__(self, *args, **kwargs): super(Tag, self).__init__(args) self.attr = self.Attr(**kwargs) def __unicode__(self): return self.unicode(indent=0) __str__ = __unicode__ def unicode(self, indent=2): l = [] SimpleUnicodeVisitor(l.append, indent).visit(self) return u("").join(l) def __repr__(self): name = self.__class__.__name__ return "<%r tag object %d>" % (name, id(self)) Namespace = NamespaceMetaclass('Namespace', (object, ), { '__tagspec__': None, '__tagclass__': Tag, '__stickyname__': False, }) class HtmlTag(Tag): def unicode(self, indent=2): l = [] HtmlVisitor(l.append, indent, shortempty=False).visit(self) return u("").join(l) # exported plain html namespace class html(Namespace): __tagclass__ = HtmlTag __stickyname__ = True __tagspec__ = dict([(x,1) for x in ( 'a,abbr,acronym,address,applet,area,article,aside,audio,b,' 'base,basefont,bdi,bdo,big,blink,blockquote,body,br,button,' 'canvas,caption,center,cite,code,col,colgroup,command,comment,' 'datalist,dd,del,details,dfn,dir,div,dl,dt,em,embed,' 'fieldset,figcaption,figure,footer,font,form,frame,frameset,h1,' 'h2,h3,h4,h5,h6,head,header,hgroup,hr,html,i,iframe,img,input,' 'ins,isindex,kbd,keygen,label,legend,li,link,listing,map,mark,' 'marquee,menu,meta,meter,multicol,nav,nobr,noembed,noframes,' 'noscript,object,ol,optgroup,option,output,p,param,pre,progress,' 'q,rp,rt,ruby,s,samp,script,section,select,small,source,span,' 'strike,strong,style,sub,summary,sup,table,tbody,td,textarea,' 'tfoot,th,thead,time,title,tr,track,tt,u,ul,xmp,var,video,wbr' ).split(',') if x]) class Style(object): def __init__(self, **kw): for x, y in kw.items(): x = x.replace('_', '-') setattr(self, x, y) class raw(object): """just a box that can contain a unicode string that will be included directly in the output""" def __init__(self, uniobj): self.uniobj = uniobj class SimpleUnicodeVisitor(object): """ recursive visitor to write unicode. """ def __init__(self, write, indent=0, curindent=0, shortempty=True): self.write = write self.cache = {} self.visited = {} # for detection of recursion self.indent = indent self.curindent = curindent self.parents = [] self.shortempty = shortempty # short empty tags or not def visit(self, node): """ dispatcher on node's class/bases name. """ cls = node.__class__ try: visitmethod = self.cache[cls] except KeyError: for subclass in cls.__mro__: visitmethod = getattr(self, subclass.__name__, None) if visitmethod is not None: break else: visitmethod = self.__object self.cache[cls] = visitmethod visitmethod(node) # the default fallback handler is marked private # to avoid clashes with the tag name object def __object(self, obj): #self.write(obj) self.write(escape(unicode(obj))) def raw(self, obj): self.write(obj.uniobj) def list(self, obj): assert id(obj) not in self.visited self.visited[id(obj)] = 1 for elem in obj: self.visit(elem) def Tag(self, tag): assert id(tag) not in self.visited try: tag.parent = self.parents[-1] except IndexError: tag.parent = None self.visited[id(tag)] = 1 tagname = getattr(tag, 'xmlname', tag.__class__.__name__) if self.curindent and not self._isinline(tagname): self.write("\n" + u(' ') * self.curindent) if tag: self.curindent += self.indent self.write(u('<%s%s>') % (tagname, self.attributes(tag))) self.parents.append(tag) for x in tag: self.visit(x) self.parents.pop() self.write(u('</%s>') % tagname) self.curindent -= self.indent else: nameattr = tagname+self.attributes(tag) if self._issingleton(tagname): self.write(u('<%s/>') % (nameattr,)) else: self.write(u('<%s></%s>') % (nameattr, tagname)) def attributes(self, tag): # serialize attributes attrlist = dir(tag.attr) attrlist.sort() l = [] for name in attrlist: res = self.repr_attribute(tag.attr, name) if res is not None: l.append(res) l.extend(self.getstyle(tag)) return u("").join(l) def repr_attribute(self, attrs, name): if name[:2] != '__': value = getattr(attrs, name) if name.endswith('_'): name = name[:-1] if isinstance(value, raw): insert = value.uniobj else: insert = escape(unicode(value)) return ' %s="%s"' % (name, insert) def getstyle(self, tag): """ return attribute list suitable for styling. """ try: styledict = tag.style.__dict__ except AttributeError: return [] else: stylelist = [x+': ' + y for x,y in styledict.items()] return [u(' style="%s"') % u('; ').join(stylelist)] def _issingleton(self, tagname): """can (and will) be overridden in subclasses""" return self.shortempty def _isinline(self, tagname): """can (and will) be overridden in subclasses""" return False class HtmlVisitor(SimpleUnicodeVisitor): single = dict([(x, 1) for x in ('br,img,area,param,col,hr,meta,link,base,' 'input,frame').split(',')]) inline = dict([(x, 1) for x in ('a abbr acronym b basefont bdo big br cite code dfn em font ' 'i img input kbd label q s samp select small span strike ' 'strong sub sup textarea tt u var'.split(' '))]) def repr_attribute(self, attrs, name): if name == 'class_': value = getattr(attrs, name) if value is None: return return super(HtmlVisitor, self).repr_attribute(attrs, name) def _issingleton(self, tagname): return tagname in self.single def _isinline(self, tagname): return tagname in self.inline class _escape: def __init__(self): self.escape = { u('"') : u('"'), u('<') : u('<'), u('>') : u('>'), u('&') : u('&'), u("'") : u('''), } self.charef_rex = re.compile(u("|").join(self.escape.keys())) def _replacer(self, match): return self.escape[match.group(0)] def __call__(self, ustring): """ xml-escape the given unicode string. """ try: ustring = unicode(ustring) except UnicodeDecodeError: ustring = unicode(ustring, 'utf-8', errors='replace') return self.charef_rex.sub(self._replacer, ustring) escape = _escape()
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