oohEmbed/app/provider/utils.py
2009-07-26 16:48:31 +08:00

110 lines
4.1 KiB
Python

import logging
import xml.etree.cElementTree as ET
from google.appengine.api import urlfetch
# xml to dict stuff from
# http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/410469
class XmlListConfig(list):
def __init__(self, aList):
for element in aList:
if element:
# treat like dict
if len(element) == 1 or element[0].tag != element[1].tag:
self.append(XmlDictConfig(element))
# treat like list
elif element[0].tag == element[1].tag:
self.append(XmlListConfig(element))
elif element.text:
text = element.text.strip()
if text:
self.append(text)
class XmlDictConfig(dict):
'''
Example usage:
>>> tree = ElementTree.parse('your_file.xml')
>>> root = tree.getroot()
>>> xmldict = XmlDictConfig(root)
Or, if you want to use an XML string:
>>> root = ElementTree.XML(xml_string)
>>> xmldict = XmlDictConfig(root)
And then use xmldict for what it is... a dict.
'''
def __init__(self, parent_element):
if parent_element.items():
self.update(dict(parent_element.items()))
for element in parent_element:
if element:
# treat like dict - we assume that if the first two tags
# in a series are different, then they are all different.
if len(element) == 1 or element[0].tag != element[1].tag:
aDict = XmlDictConfig(element)
# treat like list - we assume that if the first two tags
# in a series are the same, then the rest are the same.
else:
# here, we put the list in dictionary; the key is the
# tag name the list elements all share in common, and
# the value is the list itself
aDict = {element[0].tag: XmlListConfig(element)}
# if the tag has attributes, add those to the dict
if element.items():
aDict.update(dict(element.items()))
self.update({element.tag: aDict})
# this assumes that if you've got an attribute in a tag,
# you won't be having any text. This may or may not be a
# good idea -- time will tell. It works for the way we are
# currently doing XML configuration files...
elif element.items():
self.update({element.tag: dict(element.items())})
# finally, if there are no child tags and no attributes, extract
# the text
else:
self.update({element.tag: element.text})
def xml2dict(xml_string):
"""Returns a dictionary representation of xml in string `xml_string`"""
root = ET.fromstring(xml_string)
return XmlDictConfig(root)
class OohEmbedError(Exception):
def __init__(self, value):
self.reason = value
def __str__(self):
return repr(self.reason)
class UnsupportedUrlError(OohEmbedError):
def __init__(self):
super(UnsupportedUrlError, self).__init__("This provider does not support this URL")
class HTTPError(Exception):
def __init__(self, url, code, content=""):
self.url = url
self.code = code
self.content = content
def __str__(self):
return "HTTPError %s on url %s" % (self.url, self.code)
def get_url(url):
try:
result = urlfetch.fetch(url, headers={'User-Agent': 'oohEmbed.com'})
if result.status_code != 200:
logging.debug('Error code %s while fetching url: %s' % (result.status_code, url))
raise HTTPError(url, result.status_code, result.content)
else:
return result.content
except urlfetch.Error, e:
logging.warn("Error fetching url %s" % url, exc_info=True)
raise OohEmbedError("Error fetching url %s" % query_url)
def make_key(query_url, extra_params):
keys = sorted(extra_params.keys())
return query_url + "|".join(["%s:%s" % (key, extra_params[key]) for key in keys])