# -*- coding: utf-8 -*- from operator import and_ from dcparser import Field, WorkInfo, DCNS from librarian import (RDFNS, ValidationError, NoDublinCore, ParseError, WLURI) from xml.parsers.expat import ExpatError from os import path from StringIO import StringIO from lxml import etree from lxml.etree import (XMLSyntaxError, XSLTApplyError, Element) import re class WLPictureURI(WLURI): _re_wl_uri = re.compile('http://wolnelektury.pl/katalog/obraz/(?P[-a-z0-9]+)/?$') @classmethod def from_slug(cls, slug): uri = 'http://wolnelektury.pl/katalog/obraz/%s/' % slug return cls(uri) def as_wlpictureuri_strict(text): return WLPictureURI.strict(text) class PictureInfo(WorkInfo): """ Dublin core metadata for a picture """ FIELDS = ( Field(DCNS('language'), 'language', required=False), Field(DCNS('subject.period'), 'epochs', salias='epoch', multiple=True), Field(DCNS('subject.type'), 'kinds', salias='kind', multiple=True), Field(DCNS('subject.genre'), 'genres', salias='genre', multiple=True, required=False), Field(DCNS('subject.style'), 'styles', salias='style', multiple=True, required=False), Field(DCNS('format.dimensions'), 'dimensions', required=False), Field(DCNS('format.checksum.sha1'), 'sha1', required=True), Field(DCNS('description.medium'), 'medium', required=False), Field(DCNS('description.dimensions'), 'original_dimensions', required=False), Field(DCNS('format'), 'mime_type', required=False), Field(DCNS('identifier.url'), 'url', WLPictureURI, strict=as_wlpictureuri_strict) ) class ImageStore(object): EXT = ['gif', 'jpeg', 'png', 'swf', 'psd', 'bmp' 'tiff', 'tiff', 'jpc', 'jp2', 'jpf', 'jb2', 'swc', 'aiff', 'wbmp', 'xbm'] MIME = ['image/gif', 'image/jpeg', 'image/png', 'application/x-shockwave-flash', 'image/psd', 'image/bmp', 'image/tiff', 'image/tiff', 'application/octet-stream', 'image/jp2', 'application/octet-stream', 'application/octet-stream', 'application/x-shockwave-flash', 'image/iff', 'image/vnd.wap.wbmp', 'image/xbm'] def __init__(self, dir_): super(ImageStore, self).__init__() self.dir = dir_ def path(self, slug, mime_type): """ Finds file by slug and mime type in our iamge store. Returns a file objects (perhaps should return a filename?) """ try: i = self.MIME.index(mime_type) except ValueError: err = ValueError("Picture %s has unknown mime type: %s" % (slug, mime_type)) err.slug = slug err.mime_type = mime_type raise err ext = self.EXT[i] # add some common extensions tiff->tif, jpeg->jpg return path.join(self.dir, slug + '.' + ext) class WLPicture(object): def __init__(self, edoc, parse_dublincore=True, image_store=None): self.edoc = edoc self.image_store = image_store root_elem = edoc.getroot() dc_path = './/' + RDFNS('RDF') if root_elem.tag != 'picture': raise ValidationError("Invalid root element. Found '%s', should be 'picture'" % root_elem.tag) if parse_dublincore: self.rdf_elem = root_elem.find(dc_path) if self.rdf_elem is None: raise NoDublinCore('Document has no DublinCore - which is required.') self.picture_info = PictureInfo.from_element(self.rdf_elem) else: self.picture_info = None self.frame = None @classmethod def from_string(cls, xml, *args, **kwargs): return cls.from_file(StringIO(xml), *args, **kwargs) @classmethod def from_file(cls, xmlfile, parse_dublincore=True, image_store=None): # first, prepare for parsing if isinstance(xmlfile, basestring): file = open(xmlfile, 'rb') try: data = file.read() finally: file.close() else: data = xmlfile.read() if not isinstance(data, unicode): data = data.decode('utf-8') data = data.replace(u'\ufeff', '') # assume images are in the same directory if image_store is None and getattr(xmlfile, 'name', None): image_store = ImageStore(path.dirname(xmlfile.name)) try: parser = etree.XMLParser(remove_blank_text=False) tree = etree.parse(StringIO(data.encode('utf-8')), parser) me = cls(tree, parse_dublincore=parse_dublincore, image_store=image_store) me.load_frame_info() return me except (ExpatError, XMLSyntaxError, XSLTApplyError), e: raise ParseError(e) @property def mime_type(self): if self.picture_info is None: raise ValueError('DC is not loaded, hence we don\'t know the image type') return self.picture_info.mime_type @property def slug(self): return self.picture_info.url.slug @property def image_path(self): if self.image_store is None: raise ValueError("No image store associated with whis WLPicture.") return self.image_store.path(self.slug, self.mime_type) def image_file(self, *args, **kwargs): return open(self.image_path, *args, **kwargs) def get_sem_coords(self, sem): area = sem.find("div[@type='rect']") if area is None: area = sem.find("div[@type='whole']") return [[0, 0], [-1, -1]] def has_all_props(node, props): return reduce(and_, map(lambda prop: prop in node.attrib, props)) if not has_all_props(area, ['x1', 'x2', 'y1', 'y2']): return None def n(prop): return int(area.get(prop)) return [[n('x1'), n('y1')], [n('x2'), n('y2')]] def partiter(self): """ Iterates the parts of this picture and returns them and their metadata """ # omg no support for //sem[(@type='theme') or (@type='object')] ? for part in list(self.edoc.iterfind("//sem[@type='theme']")) +\ list(self.edoc.iterfind("//sem[@type='object']")): pd = {'type': part.get('type')} coords = self.get_sem_coords(part) if coords is None: continue pd['coords'] = coords def want_unicode(x): if not isinstance(x, unicode): return x.decode('utf-8') else: return x pd['object'] = part.attrib['type'] == 'object' and want_unicode(part.attrib.get('object', u'')) or None pd['themes'] = part.attrib['type'] == 'theme' and [part.attrib.get('theme', u'')] or [] yield pd def load_frame_info(self): k = self.edoc.find("//sem[@object='kadr']") if k is not None: clip = self.get_sem_coords(k) self.frame = clip frm = Element("sem", {"type": "frame"}) frm.append(k.iter("div").next()) self.edoc.getroot().append(frm) k.getparent().remove(k) else: frm = self.edoc.find("//sem[@type='frame']") if frm: self.frame = self.get_sem_coords(frm) else: self.frame = None return self