django-select2/django_select2/util.py
2013-09-15 13:38:41 +05:30

334 lines
9.7 KiB
Python

import datetime
import hashlib
import logging
import re
import threading
import types
from django.utils.encoding import force_unicode
logger = logging.getLogger(__name__)
class JSVar(unicode):
"""
A JS variable.
This is a simple unicode string. This class type acts as a marker that this string is a JS variable name,
so it must not be quoted by :py:func:`.convert_py_to_js_data` while rendering the JS code.
"""
pass
class JSFunction(JSVar):
"""
A JS function name.
From rendering point of view, rendering this is no different from :py:class:`JSVar`. After all, a JS varible
can refer a function instance, primitive constant or any other object. They are still all varibles.
.. tip:: Do use this marker for JS functions. This will make the code clearer, and the purpose more easier to
understand.
"""
pass
class JSFunctionInContext(JSVar):
"""
A JS function name to run in context of some other Html DOM element.
Like :py:class:`JSFunction`, this too flags the string as JS function, but with a special requirement. The JS function
needs to be invoked in the context of a Html DOM, such that, ``this`` inside the function refers to that DOM instead of
``window``.
.. tip:: JS functions of this type are warapped inside special another JS function -- ``django_select2.runInContextHelper``.
"""
pass
def render_js_script(inner_code):
"""
This wraps ``inner_code`` string inside the following code block::
<script type="text/javascript">
$(function () {
// inner_code here
});
</script>
:rtype: :py:obj:`unicode`
"""
return u"""
<script type="text/javascript">
$(function () {
%s
});
</script>""" % inner_code
def extract_some_key_val(dct, keys):
"""
Gets a sub-set of a :py:obj:`dict`.
:param dct: Source dictionary.
:type dct: :py:obj:`dict`
:param keys: List of subset keys, which to extract from ``dct``.
:type keys: :py:obj:`list` or any iterable.
:rtype: :py:obj:`dict`
"""
edct = {}
for k in keys:
v = dct.get(k, None)
if v is not None:
edct[k] = v
return edct
def convert_to_js_str(val):
val = force_unicode(val).replace('\'', '\\\'')
return u"'%s'" % val
def convert_py_to_js_data(val, id_):
"""
Converts Python data type to JS data type.
Practically what this means is, convert ``False`` to ``false``, ``True`` to ``true`` and so on.
It also takes care of the conversion of :py:class:`.JSVar`, :py:class:`.JSFunction`
and :py:class:`.JSFunctionInContext`. It takes care of recursively converting lists and dictionaries
too.
:param val: The Python data to convert.
:type val: Any
:param id_: The DOM id of the element in which context :py:class:`.JSFunctionInContext` functions
should run. (This is not needed if ``val`` contains no :py:class:`.JSFunctionInContext`)
:type id_: :py:obj:`str`
:rtype: :py:obj:`unicode`
"""
if type(val) == types.BooleanType:
return u'true' if val else u'false'
elif type(val) in [types.IntType, types.LongType, types.FloatType]:
return force_unicode(val)
elif isinstance(val, JSFunctionInContext):
return u"django_select2.runInContextHelper(%s, '%s')" % (val, id_)
elif isinstance(val, JSVar):
return val # No quotes here
elif isinstance(val, dict):
return convert_dict_to_js_map(val, id_)
elif isinstance(val, list):
return convert_to_js_arr(val, id_)
else:
return convert_to_js_str(val)
def convert_dict_to_js_map(dct, id_):
"""
Converts a Python dictionary to JS map.
:param dct: The Python dictionary to convert.
:type dct: :py:obj:`dict`
:param id_: The DOM id of the element in which context :py:class:`.JSFunctionInContext` functions
should run. (This is not needed if ``dct`` contains no :py:class:`.JSFunctionInContext`)
:type id_: :py:obj:`str`
:rtype: :py:obj:`unicode`
"""
out = u'{'
is_first = True
for name in dct:
if not is_first:
out += u", "
else:
is_first = False
out += u"%s: " % convert_to_js_str(name)
out += convert_py_to_js_data(dct[name], id_)
return out + u'}'
def convert_to_js_arr(lst, id_):
"""
Converts a Python list (or any iterable) to JS array.
:param lst: The Python iterable to convert.
:type lst: :py:obj:`list` or Any iterable
:param id_: The DOM id of the element in which context :py:class:`.JSFunctionInContext` functions
should run. (This is not needed if ``lst`` contains no :py:class:`.JSFunctionInContext`)
:type id_: :py:obj:`str`
:rtype: :py:obj:`unicode`
"""
out = u'['
is_first = True
for val in lst:
if not is_first:
out += u", "
else:
is_first = False
out += convert_py_to_js_data(val, id_)
return out + u']'
def convert_to_js_string_arr(lst):
"""
Converts a Python list (or any iterable) of strings to JS array.
:py:func:`convert_to_js_arr` can always be used instead of this. However, since it
knows that it only contains strings, it cuts down on unnecessary computations.
:rtype: :py:obj:`unicode`
"""
lst = [convert_to_js_str(l) for l in lst]
return u"[%s]" % (",".join(lst))
### Auto view helper utils ###
from . import __ENABLE_MULTI_PROCESS_SUPPORT as ENABLE_MULTI_PROCESS_SUPPORT, \
__MEMCACHE_HOST as MEMCACHE_HOST, __MEMCACHE_PORT as MEMCACHE_PORT, __MEMCACHE_TTL as MEMCACHE_TTL
from . import __GENERATE_RANDOM_ID as GENERATE_RANDOM_ID, __SECRET_SALT as SECRET_SALT
def synchronized(f):
"Decorator to synchronize multiple calls to a functions."
f.__lock__ = threading.Lock()
def synced_f(*args, **kwargs):
with f.__lock__:
return f(*args, **kwargs)
synced_f.__doc__ = f.__doc__
return synced_f
# Generated Id to field instance mapping.
__id_store = {}
# Field's key to generated Id mapping.
__field_store = {}
ID_PATTERN = r"[0-9_a-zA-Z.:+\- ]+"
def is_valid_id(val):
"""
Checks if ``val`` is a valid generated Id.
:param val: The value to check.
:type val: :py:obj:`str`
:rtype: :py:obj:`bool`
"""
regex = "^%s$" % ID_PATTERN
if re.match(regex, val) is None:
return False
else:
return True
if ENABLE_MULTI_PROCESS_SUPPORT:
from memcache_wrapped_db_client import Client
remote_server = Client(MEMCACHE_HOST, str(MEMCACHE_PORT), MEMCACHE_TTL)
@synchronized
def register_field(key, field):
"""
Registers an Auto field for use with :py:class:`.views.AutoResponseView`.
:param key: The key to use while registering this field.
:type key: :py:obj:`unicode`
:param field: The field to register.
:type field: :py:class:`AutoViewFieldMixin`
:return: The generated Id for this field. If given ``key`` was already registered then the
Id generated that time, would be returned.
:rtype: :py:obj:`unicode`
"""
global __id_store, __field_store
from fields import AutoViewFieldMixin
if not isinstance(field, AutoViewFieldMixin):
raise ValueError('Field must extend AutoViewFieldMixin')
if key not in __field_store:
# Generating id
if GENERATE_RANDOM_ID:
id_ = u"%d:%s" % (len(__id_store), unicode(datetime.datetime.now()))
else:
id_ = unicode(hashlib.sha1("%s:%s" % (key, SECRET_SALT)).hexdigest())
__field_store[key] = id_
__id_store[id_] = field
if logger.isEnabledFor(logging.INFO):
logger.info("Registering new field: %s; With actual id: %s", key, id_)
if ENABLE_MULTI_PROCESS_SUPPORT:
logger.info("Multi process support is enabled. Adding id-key mapping to remote server.")
remote_server.set(id_, key)
else:
id_ = __field_store[key]
if logger.isEnabledFor(logging.INFO):
logger.info("Field already registered: %s; With actual id: %s", key, id_)
return id_
def get_field(id_):
"""
Returns an Auto field instance registered with the given Id.
:param id_: The generated Id the field is registered with.
:type id_: :py:obj:`unicode`
:rtype: :py:class:`AutoViewFieldMixin` or None
"""
field = __id_store.get(id_, None)
if field is None and ENABLE_MULTI_PROCESS_SUPPORT:
if logger.isEnabledFor(logging.DEBUG):
logger.debug('Id "%s" not found in this process. Looking up in remote server.', id_)
key = remote_server.get(id_)
if key is not None:
id_in_current_instance = __field_store[key]
if id_in_current_instance:
field = __id_store.get(id_in_current_instance, None)
if field:
__id_store[id_] = field
else:
logger.error('Unknown id "%s".', id_in_current_instance)
else:
logger.error('Unknown id "%s".', id_)
return field
def timer_start(name):
import sys, time
if sys.platform == "win32":
# On Windows, the best timer is time.clock()
default_timer = time.clock
multiplier = 1.0
else:
# On most other platforms the best timer is time.time()
default_timer = time.time
multiplier = 1000.0
return (name, default_timer, multiplier, default_timer())
def timer_end(t):
(name, default_timer, multiplier, timeS) = t
timeE = default_timer()
logger.debug("Time taken by %s: %0.3f ms" % (name, (timeE - timeS) * multiplier))
def timer(f):
def inner(*args, **kwargs):
t = timer_start(f.func_name)
ret = f(*args, **kwargs)
timer_end(t)
return ret
return inner