pysonic/pysonic/apilib.py
2018-04-05 19:02:17 -07:00

144 lines
5.6 KiB
Python

from collections import defaultdict
from bs4 import BeautifulSoup
import re
import cherrypy
import json
CALLBACK_RE = re.compile(r'^[a-zA-Z0-9_]+$')
response_formats = defaultdict(lambda: "render_xml")
response_formats["json"] = "render_json"
response_formats["jsonp"] = "render_jsonp"
response_headers = defaultdict(lambda: "text/xml; charset=utf-8")
response_headers["json"] = "application/json; charset=utf-8"
response_headers["jsonp"] = "text/javascript; charset=utf-8"
def formatresponse(func):
"""
Decorator for rendering ApiResponse responses based on requested response type
"""
def wrapper(*args, **kwargs):
response = func(*args, **kwargs)
response_format = kwargs.get("f", "xml")
callback = kwargs.get("callback", None)
cherrypy.response.headers['Content-Type'] = response_headers[response_format]
renderer = getattr(response, response_formats[response_format])
if response_format == "jsonp":
if callback is None:
return response.render_xml().encode('UTF-8') # copy original subsonic behavior
else:
return renderer(callback).encode('UTF-8')
return renderer().encode('UTF-8')
return wrapper
class ApiResponse(object):
def __init__(self, status="ok", version="1.15.0"):
"""
ApiResponses are python data structures that can be converted to other formats. The response has a status and a
version. The response data structure is stored in self.data and follows these rules:
- self.data is a dict
- the dict's values become either child nodes or attributes, named by the key
- lists become many oner one child
- dict values are not allowed
- all other types (str, int, NoneType) are attributes
:param status:
:param version:
"""
self.status = status
self.version = version
self.data = defaultdict(lambda: list())
def add_child(self, _type, _parent="", _real_parent=None, **kwargs):
kwargs = {k: v for k, v in kwargs.items() if v or type(v) is int} # filter out empty keys (0 is ok)
parent = _real_parent if _real_parent else self.get_child(_parent)
m = defaultdict(lambda: list())
m.update(dict(kwargs))
parent[_type].append(m)
return m
def get_child(self, _path):
parent_path = _path.split(".")
parent = self.data
for item in parent_path:
if not item:
continue
parent = parent.get(item)[0]
return parent
def set_attrs(self, _path, **attrs):
parent = self.get_child(_path)
if type(parent) not in (dict, defaultdict):
raise Exception("wot")
parent.update(attrs)
def render_json(self):
def _flatten_json(item):
"""
Convert defaultdicts to dicts and remove lists where node has 1 or no child
"""
listed_attrs = ["folder"]
d = {}
for k, v in item.items():
if type(v) is list:
if len(v) > 1:
d[k] = []
for subitem in v:
d[k].append(_flatten_json(subitem))
elif len(v) == 1:
d[k] = _flatten_json(v[0])
else:
d[k] = {}
else:
d[k] = [v] if k in listed_attrs else v
return d
data = _flatten_json(self.data)
return json.dumps({"subsonic-response": dict(status=self.status, version=self.version, **data)}, indent=4)
def render_jsonp(self, callback):
assert CALLBACK_RE.match(callback), "Invalid callback"
return "{}({});".format(callback, self.render_json())
def render_xml(self):
text_attrs = ['largeImageUrl', 'musicBrainzId', 'smallImageUrl', 'mediumImageUrl', 'lastFmUrl', 'biography',
'folder']
selftext_attrs = ['value']
# These attributes will be placed in <hello>{{ value }}</hello> tags instead of hello="{{ value }}" on parent
doc = BeautifulSoup('', features='lxml-xml')
root = doc.new_tag("subsonic-response", xmlns="http://subsonic.org/restapi",
status=self.status,
version=self.version)
doc.append(root)
def _render_xml(node, parent):
"""
For every key in the node dict, the parent gets a new child tag with name == key
If the value is a dict, it becomes the new tag's attrs
If the value is a list, the parent gets many new tags with each dict as attrs
If the value is str int etc, parent gets attrs
"""
for key, value in node.items():
if type(value) in (dict, defaultdict):
tag = doc.new_tag(key)
parent.append(tag)
tag.attrs.update(value)
elif type(value) is list:
for item in value:
tag = doc.new_tag(key)
parent.append(tag)
_render_xml(item, tag)
else:
if key in text_attrs:
tag = doc.new_tag(key)
parent.append(tag)
tag.append(str(value))
elif key in selftext_attrs:
parent.append(str(value))
else:
parent.attrs[key] = value
_render_xml(self.data, root)
return doc.prettify()