I see in the piston code that the xml mimer that is registered is:
Mimer.register(lambda *a: None, ('text/xml',))
Do we have to register our own XML mimer or is there something going on somewhere else in the code that I haven't found? If we need to register our own where is the best place to do that? I typically use beautiful soup for parsing XML, does anyone have any advice on what they use?
then you need a file xml2dict.py (we usually have an app called "api"):
"""xml2dict: Convert bewteen xml file and python dict """
from api.oodict import OODict import re
try: import xml.etree.ElementTree as ET except: import cElementTree as ET # for 2.4
class XML2Dict:
def __init__(self): pass
def _parse_node(self, node): tree = OODict() # Save value value = node.text if isinstance(value, str): value = value.strip() # Only strip strings tree.value = value # Save attributes for k,v in node.attrib.items(): tree.update(self._make_dict(k, v)) #Save childrens for child in node.getchildren(): ctag = child.tag ctree = self._parse_node(child) cdict = self._make_dict(ctag, ctree)
if ctag not in tree: # First time found tree.update(cdict) continue
old = tree[ctag] if not isinstance(old, list): tree[ctag] = [old] # Multi entries, change to list tree[ctag].append(ctree) # Add new entry
tmp = value result = re.compile("\{(.*)\}(.*)").search(tag) if result: tmp = OODict() tmp.xmlns, tag = result.groups() # We have a namespace! tmp.value = value return OODict({tag: tmp})
def parse(self, file): """Parse xml file to dict""" f = open(file, 'r') return self.fromstring(f.read())
def fromstring(self, s): """Parse xml string to dict""" tmp = ET.fromstring(s) return self._make_dict(tmp.tag, self._parse_node(tmp))
––––––––––
and a second file oodict.py:
"""OODict: object view of dict
Copyright (C) 2008-2009 Chen Zheng <nkch...@gmail.com> Distributed under terms of GPL v2 """
Problems: * can't use del a.c, must use a['c'] *If a.k is a dict, v is returned still as a dict in the following code: for k, v in a.items(): pass # v is still a dict
You can use like this instead: for k in a.keys(): v = a[k] # v is a OODict now
Perhaps we should define our own 'items'. """
def __init__(self, data = {}): dict.__init__(self, data)
def __getitem__(self, key): value = dict.__getitem__(self, key)
if isinstance(value, dict) and value.keys() == ['value']: value = value['value']
if isinstance(value, dict) and not isinstance(value, OODict): # Fixme! There maybe a problem here when value is a subclass of dict value = OODict(value) self[key] = value # Auto covert children dict to OODict return value
> I see in the piston code that the xml mimer that is registered is:
> Mimer.register(lambda *a: None, ('text/xml',))
> Do we have to register our own XML mimer or is there something going > on somewhere else in the code that I haven't found? If we need to > register our own where is the best place to do that? I typically use > beautiful soup for parsing XML, does anyone have any advice on what > they use?
Patrick, thanks for this code. It works very well and seems a neat solution. Currently my handlers all work with the dictionaries built from django's JSON parser. That being the case I think I'm going to take your code and see if I can modify it so that the XML is parsed into the same dictionary structure that my handlers already work with. This will hopefully mean that I can use the same logic for handling both XML and JSON. For the API I'm building I'm only interested in JSON and XML but I think if I can get an XML parser working so that handlers don't need to worry about the difference between these two formats then it would be something really useful.
Perhaps when finished, if it works well enough, I'll contact jespern and see if it could be added to the piston source as the XML mimer. Would be nice to have something out of the box in the piston source.
Thanks again Patrick, very useful.
On Dec 20, 3:00 pm, patrickk <sehmasch...@gmail.com> wrote:
> then you need a file xml2dict.py (we usually have an app called > "api"):
> """xml2dict: Convert bewteen xml file and python dict """
> from api.oodict import OODict > import re
> try: > import xml.etree.ElementTree as ET > except: > import cElementTree as ET # for 2.4
> class XML2Dict:
> def __init__(self): > pass
> def _parse_node(self, node): > tree = OODict() > # Save value > value = node.text > if isinstance(value, str): > value = value.strip() # Only strip strings > tree.value = value > # Save attributes > for k,v in node.attrib.items(): > tree.update(self._make_dict(k, v)) > #Save childrens > for child in node.getchildren(): > ctag = child.tag > ctree = self._parse_node(child) > cdict = self._make_dict(ctag, ctree)
> if ctag not in tree: # First time found > tree.update(cdict) > continue
> old = tree[ctag] > if not isinstance(old, list): > tree[ctag] = [old] # Multi entries, change to list > tree[ctag].append(ctree) # Add new entry
> tmp = value > result = re.compile("\{(.*)\}(.*)").search(tag) > if result: > tmp = OODict() > tmp.xmlns, tag = result.groups() # We have a namespace! > tmp.value = value > return OODict({tag: tmp})
> def parse(self, file): > """Parse xml file to dict""" > f = open(file, 'r') > return self.fromstring(f.read())
> def fromstring(self, s): > """Parse xml string to dict""" > tmp = ET.fromstring(s) > return self._make_dict(tmp.tag, self._parse_node(tmp))
> ––––––––––
> and a second file oodict.py:
> """OODict: object view of dict
> Copyright (C) 2008-2009 Chen Zheng <nkch...@gmail.com> > Distributed under terms of GPL v2 > """
> Problems: > * can't use del a.c, must use a['c'] > *If a.k is a dict, v is returned still as a dict in the following > code: > for k, v in a.items(): > pass # v is still a dict
> You can use like this instead: > for k in a.keys(): > v = a[k] # v is a OODict now
> Perhaps we should define our own 'items'. > """
> def __init__(self, data = {}): > dict.__init__(self, data)
> def __getitem__(self, key): > value = dict.__getitem__(self, key)
> if isinstance(value, dict) and value.keys() == ['value']: > value = value['value']
> if isinstance(value, dict) and not isinstance(value, OODict): > # Fixme! There maybe a problem here when value is a > subclass of dict > value = OODict(value) > self[key] = value # Auto covert children dict to OODict > return value
> > Do we have to register our own XML mimer or is there something going > > on somewhere else in the code that I haven't found? If we need to > > register our own where is the best place to do that? I typically use > > beautiful soup for parsing XML, does anyone have any advice on what > > they use?
> Patrick, thanks for this code. It works very well and seems a neat > solution. Currently my handlers all work with the dictionaries built > from django's JSON parser. That being the case I think I'm going to > take your code and see if I can modify it so that the XML is parsed > into the same dictionary structure that my handlers already work with. > This will hopefully mean that I can use the same logic for handling > both XML and JSON. For the API I'm building I'm only interested in > JSON and XML but I think if I can get an XML parser working so that > handlers don't need to worry about the difference between these two > formats then it would be something really useful.
> Perhaps when finished, if it works well enough, I'll contact jespern > and see if it could be added to the piston source as the XML mimer. > Would be nice to have something out of the box in the piston source.
> Thanks again Patrick, very useful.
> On Dec 20, 3:00 pm, patrickk <sehmasch...@gmail.com> wrote:
> > we use a custom version of XML2Dict.
> > in piston/emitters.py:
> > def xml_deserializer(data): > > from api.xml2dict import XML2Dict
> > xml = XML2Dict() > > r = xml.fromstring(data) > > return r
> > then you need a file xml2dict.py (we usually have an app called > > "api"):
> > """xml2dict: Convert bewteen xml file and python dict """
> > from api.oodict import OODict > > import re
> > try: > > import xml.etree.ElementTree as ET > > except: > > import cElementTree as ET # for 2.4
> > class XML2Dict:
> > def __init__(self): > > pass
> > def _parse_node(self, node): > > tree = OODict() > > # Save value > > value = node.text > > if isinstance(value, str): > > value = value.strip() # Only strip strings > > tree.value = value > > # Save attributes > > for k,v in node.attrib.items(): > > tree.update(self._make_dict(k, v)) > > #Save childrens > > for child in node.getchildren(): > > ctag = child.tag > > ctree = self._parse_node(child) > > cdict = self._make_dict(ctag, ctree)
> > if ctag not in tree: # First time found > > tree.update(cdict) > > continue
> > old = tree[ctag] > > if not isinstance(old, list): > > tree[ctag] = [old] # Multi entries, change to list > > tree[ctag].append(ctree) # Add new entry
> > tmp = value > > result = re.compile("\{(.*)\}(.*)").search(tag) > > if result: > > tmp = OODict() > > tmp.xmlns, tag = result.groups() # We have a namespace! > > tmp.value = value > > return OODict({tag: tmp})
> > def parse(self, file): > > """Parse xml file to dict""" > > f = open(file, 'r') > > return self.fromstring(f.read())
> > Problems: > > * can't use del a.c, must use a['c'] > > *If a.k is a dict, v is returned still as a dict in the following > > code: > > for k, v in a.items(): > > pass # v is still a dict
> > You can use like this instead: > > for k in a.keys(): > > v = a[k] # v is a OODict now
> > Perhaps we should define our own 'items'. > > """
> > if isinstance(value, dict) and value.keys() == ['value']: > > value = value['value']
> > if isinstance(value, dict) and not isinstance(value, OODict): > > # Fixme! There maybe a problem here when value is a > > subclass of dict > > value = OODict(value) > > self[key] = value # Auto covert children dict to OODict > > return value
> > > Do we have to register our own XML mimer or is there something going > > > on somewhere else in the code that I haven't found? If we need to > > > register our own where is the best place to do that? I typically use > > > beautiful soup for parsing XML, does anyone have any advice on what > > > they use?
The mimer creates a dictionary like the one you get from the JSON mimer. It's what I'm using now as it means I don't have to change any handler code that already works with JSON requests.
Hopefully it'll be of use to others.
On Dec 21, 7:50 am, patrickk <sehmasch...@gmail.com> wrote:
> On Dec 20, 9:10 pm, cootetom <coote...@gmail.com> wrote:
> > Patrick, thanks for this code. It works very well and seems a neat > > solution. Currently my handlers all work with the dictionaries built > > from django's JSON parser. That being the case I think I'm going to > > take your code and see if I can modify it so that the XML is parsed > > into the same dictionary structure that my handlers already work with. > > This will hopefully mean that I can use the same logic for handling > > both XML and JSON. For the API I'm building I'm only interested in > > JSON and XML but I think if I can get an XML parser working so that > > handlers don't need to worry about the difference between these two > > formats then it would be something really useful.
> > Perhaps when finished, if it works well enough, I'll contact jespern > > and see if it could be added to the piston source as the XML mimer. > > Would be nice to have something out of the box in the piston source.
> > Thanks again Patrick, very useful.
> > On Dec 20, 3:00 pm, patrickk <sehmasch...@gmail.com> wrote:
> > > then you need a file xml2dict.py (we usually have an app called > > > "api"):
> > > """xml2dict: Convert bewteen xml file and python dict """
> > > from api.oodict import OODict > > > import re
> > > try: > > > import xml.etree.ElementTree as ET > > > except: > > > import cElementTree as ET # for 2.4
> > > class XML2Dict:
> > > def __init__(self): > > > pass
> > > def _parse_node(self, node): > > > tree = OODict() > > > # Save value > > > value = node.text > > > if isinstance(value, str): > > > value = value.strip() # Only strip strings > > > tree.value = value > > > # Save attributes > > > for k,v in node.attrib.items(): > > > tree.update(self._make_dict(k, v)) > > > #Save childrens > > > for child in node.getchildren(): > > > ctag = child.tag > > > ctree = self._parse_node(child) > > > cdict = self._make_dict(ctag, ctree)
> > > if ctag not in tree: # First time found > > > tree.update(cdict) > > > continue
> > > old = tree[ctag] > > > if not isinstance(old, list): > > > tree[ctag] = [old] # Multi entries, change to list > > > tree[ctag].append(ctree) # Add new entry
> > > Problems: > > > * can't use del a.c, must use a['c'] > > > *If a.k is a dict, v is returned still as a dict in the following > > > code: > > > for k, v in a.items(): > > > pass # v is still a dict
> > > You can use like this instead: > > > for k in a.keys(): > > > v = a[k] # v is a OODict now
> > > Perhaps we should define our own 'items'. > > > """
> > > if isinstance(value, dict) and value.keys() == ['value']: > > > value = value['value']
> > > if isinstance(value, dict) and not isinstance(value, OODict): > > > # Fixme! There maybe a problem here when value is a > > > subclass of dict > > > value = OODict(value) > > > self[key] = value # Auto covert children dict to OODict > > > return value
> > > > Do we have to register our own XML mimer or is there something going > > > > on somewhere else in the code that I haven't found? If we need to > > > > register our own where is the best place to do that? I typically use > > > > beautiful soup for parsing XML, does anyone have any advice on what > > > > they use?
