Package Gnumed :: Package pycommon :: Module gmBusinessDBObject
[frames] | no frames]

Source Code for Module Gnumed.pycommon.gmBusinessDBObject

  1  """GNUmed database object business class. 
  2   
  3  Overview 
  4  -------- 
  5  This class wraps a source relation (table, view) which 
  6  represents an entity that makes immediate business sense 
  7  such as a vaccination or a medical document. In many if 
  8  not most cases this source relation is a denormalizing 
  9  view. The data in that view will in most cases, however, 
 10  originate from several normalized tables. One instance 
 11  of this class represents one row of said source relation. 
 12   
 13  Note, however, that this class does not *always* simply 
 14  wrap a single table or view. It can also encompass several 
 15  relations (views, tables, sequences etc) that taken together 
 16  form an object meaningful to *business* logic. 
 17   
 18  Initialization 
 19  -------------- 
 20  There are two ways to initialize an instance with values. 
 21  One way is to pass a "primary key equivalent" object into 
 22  __init__(). Refetch_payload() will then pull the data from 
 23  the backend. Another way would be to fetch the data outside 
 24  the instance and pass it in via the <row> argument. In that 
 25  case the instance will not initially connect to the databse 
 26  which may offer a great boost to performance. 
 27   
 28  Values API 
 29  ---------- 
 30  Field values are cached for later access. They can be accessed 
 31  by a dictionary API, eg: 
 32   
 33          old_value = object['field'] 
 34          object['field'] = new_value 
 35   
 36  The field names correspond to the respective column names 
 37  in the "main" source relation. Accessing non-existant field 
 38  names will raise an error, so does trying to set fields not 
 39  listed in self.__class__._updatable_fields. To actually 
 40  store updated values in the database one must explicitly 
 41  call save_payload(). 
 42   
 43  The class will in many cases be enhanced by accessors to 
 44  related data that is not directly part of the business 
 45  object itself but are closely related, such as codes 
 46  linked to a clinical narrative entry (eg a diagnosis). Such 
 47  accessors in most cases start with get_*. Related setters 
 48  start with set_*. The values can be accessed via the 
 49  object['field'] syntax, too, but they will be cached 
 50  independantly. 
 51   
 52  Concurrency handling 
 53  -------------------- 
 54  GNUmed connections always run transactions in isolation level 
 55  "serializable". This prevents transactions happening at the 
 56  *very same time* to overwrite each other's data. All but one 
 57  of them will abort with a concurrency error (eg if a 
 58  transaction runs a select-for-update later than another one 
 59  it will hang until the first transaction ends. Then it will 
 60  succeed or fail depending on what the first transaction 
 61  did). This is standard transactional behaviour. 
 62   
 63  However, another transaction may have updated our row 
 64  between the time we first fetched the data and the time we 
 65  start the update transaction. This is noticed by getting the 
 66  XMIN system column for the row when initially fetching the 
 67  data and using that value as a where condition value when 
 68  updating the row later. If the row had been updated (xmin 
 69  changed) or deleted (primary key disappeared) in the 
 70  meantime the update will touch zero rows (as no row with 
 71  both PK and XMIN matching is found) even if the query itself 
 72  syntactically succeeds. 
 73   
 74  When detecting a change in a row due to XMIN being different 
 75  one needs to be careful how to represent that to the user. 
 76  The row may simply have changed but it also might have been 
 77  deleted and a completely new and unrelated row which happens 
 78  to have the same primary key might have been created ! This 
 79  row might relate to a totally different context (eg. patient, 
 80  episode, encounter). 
 81   
 82  One can offer all the data to the user: 
 83   
 84  self.original_payload 
 85  - contains the data at the last successful refetch 
 86   
 87  self.modified_payload 
 88  - contains the modified payload just before the last 
 89    failure of save_payload() - IOW what is currently 
 90    in the database 
 91   
 92  self._payload 
 93  - contains the currently active payload which may or 
 94    may not contain changes 
 95   
 96  For discussion on this see the thread starting at: 
 97   
 98          http://archives.postgresql.org/pgsql-general/2004-10/msg01352.php 
 99   
100  and here 
101   
102          http://groups.google.com/group/pgsql.general/browse_thread/thread/e3566ba76173d0bf/6cf3c243a86d9233 
103          (google for "XMIN semantic at peril") 
104   
105  Problem cases with XMIN: 
106   
107  1) not unlikely 
108  - a very old row is read with XMIN 
109  - vacuum comes along and sets XMIN to FrozenTransactionId 
110    - now XMIN changed but the row actually didn't ! 
111  - an update with "... where xmin = old_xmin ..." fails 
112    although there is no need to fail 
113   
114  2) quite unlikely 
115  - a row is read with XMIN 
116  - a long time passes 
117  - the original XMIN gets frozen to FrozenTransactionId 
118  - another writer comes along and changes the row 
119  - incidentally the exact same old row gets the old XMIN *again* 
120    - now XMIN is (again) the same but the data changed ! 
121  - a later update fails to detect the concurrent change !! 
122   
123  TODO: 
124  The solution is to use our own column for optimistic locking 
125  which gets updated by an AFTER UPDATE trigger. 
126  """ 
127  #============================================================ 
128  __author__ = "K.Hilbert <Karsten.Hilbert@gmx.net>" 
129  __license__ = "GPL v2 or later" 
130   
131   
132  import sys 
133  import types 
134  import inspect 
135  import logging 
136  import datetime 
137   
138   
139  if __name__ == '__main__': 
140          sys.path.insert(0, '../../') 
141  from Gnumed.pycommon import gmExceptions 
142  from Gnumed.pycommon import gmPG2 
143  from Gnumed.pycommon.gmTools import tex_escape_string 
144   
145   
146  _log = logging.getLogger('gm.db') 
147  #============================================================ 
148 -class cBusinessDBObject(object):
149 """Represents business objects in the database. 150 151 Rules: 152 - instances ARE ASSUMED TO EXIST in the database 153 - PK construction (aPK_obj): DOES verify its existence on instantiation 154 (fetching data fails) 155 - Row construction (row): allowed by using a dict of pairs 156 field name: field value (PERFORMANCE improvement) 157 - does NOT verify FK target existence 158 - does NOT create new entries in the database 159 - does NOT lazy-fetch fields on access 160 161 Class scope SQL commands and variables: 162 163 <_cmd_fetch_payload> 164 - must return exactly one row 165 - where clause argument values are expected 166 in self.pk_obj (taken from __init__(aPK_obj)) 167 - must return xmin of all rows that _cmds_store_payload 168 will be updating, so views must support the xmin columns 169 of their underlying tables 170 171 <_cmds_store_payload> 172 - one or multiple "update ... set ... where xmin_* = ..." statements 173 which actually update the database from the data in self._payload, 174 - the last query must refetch at least the XMIN values needed to detect 175 concurrent updates, their field names had better be the same as 176 in _cmd_fetch_payload, 177 - when subclasses tend to live a while after save_payload() was 178 called and they support computed fields (say, _(some_column) 179 you need to return *all* columns (see cEncounter) 180 181 <_updatable_fields> 182 - a list of fields available for update via object['field'] 183 184 185 A template for new child classes: 186 187 *********** start of template *********** 188 189 #------------------------------------------------------------ 190 from Gnumed.pycommon import gmBusinessDBObject 191 from Gnumed.pycommon import gmPG2 192 193 #============================================================ 194 # short description 195 #------------------------------------------------------------ 196 # use plural form, search-replace get_XXX 197 _SQL_get_XXX = u\""" 198 SELECT *, (xmin AS xmin_XXX) 199 FROM XXX.v_XXX 200 WHERE %s 201 \""" 202 203 class cXxxXxx(gmBusinessDBObject.cBusinessDBObject): 204 \"""Represents ...\""" 205 206 _cmd_fetch_payload = _SQL_get_XXX % u"pk_XXX = %s" 207 _cmds_store_payload = [ 208 u\""" 209 -- typically the underlying table name 210 UPDATE xxx.xxx SET 211 -- typically "table_col = %(view_col)s" 212 xxx = %(xxx)s, 213 xxx = gm.nullify_empty_string(%(xxx)s) 214 WHERE 215 pk = %(pk_XXX)s 216 AND 217 xmin = %(xmin_XXX)s 218 RETURNING 219 pk as pk_XXX, 220 xmin as xmin_XXX 221 \""" 222 ] 223 # view columns that can be updated: 224 _updatable_fields = [ 225 u'xxx', 226 u'xxx' 227 ] 228 #-------------------------------------------------------- 229 def format(self): 230 return u'%s' % self 231 232 #------------------------------------------------------------ 233 def get_XXX(order_by=None): 234 if order_by is None: 235 order_by = u'true' 236 else: 237 order_by = u'true ORDER BY %s' % order_by 238 239 cmd = _SQL_get_XXX % order_by 240 rows, idx = gmPG2.run_ro_queries(queries = [{'cmd': cmd}], get_col_idx = True) 241 return [ cXxxXxx(row = {'data': r, 'idx': idx, 'pk_field': 'xxx'}) for r in rows ] 242 #------------------------------------------------------------ 243 def create_xxx(xxx=None, xxx=None): 244 245 args = { 246 u'xxx': xxx, 247 u'xxx': xxx 248 } 249 cmd = u\""" 250 INSERT INTO xxx.xxx ( 251 xxx, 252 xxx, 253 xxx 254 ) VALUES ( 255 %(xxx)s, 256 %(xxx)s, 257 gm.nullify_empty_string(%(xxx)s) 258 ) 259 RETURNING pk 260 \""" 261 rows, idx = gmPG2.run_rw_queries(queries = [{'cmd': cmd, 'args': args}], return_data = True, get_col_idx = False) 262 263 return cXxxXxx(aPK_obj = rows[0]['pk']) 264 #------------------------------------------------------------ 265 def delete_xxx(xxx=None): 266 args = {'pk': xxx} 267 cmd = u"DELETE FROM xxx.xxx WHERE pk = %(pk)s" 268 gmPG2.run_rw_queries(queries = [{'cmd': cmd, 'args': args}]) 269 return True 270 #------------------------------------------------------------ 271 272 *********** end of template *********** 273 274 """ 275 #--------------------------------------------------------
276 - def __init__(self, aPK_obj=None, row=None):
277 """Init business object. 278 279 Call from child classes: 280 281 super(cChildClass, self).__init__(aPK_obj = aPK_obj, row = row) 282 """ 283 # initialize those "too early" because checking descendants might 284 # fail which will then call __str__ in stack trace logging if --debug 285 # was given which in turn needs those instance variables 286 self.pk_obj = '<uninitialized>' 287 self._idx = {} 288 self._payload = [] # the cache for backend object values (mainly table fields) 289 self._ext_cache = {} # the cache for extended method's results 290 self._is_modified = False 291 292 # check descendants 293 self.__class__._cmd_fetch_payload 294 self.__class__._cmds_store_payload 295 self.__class__._updatable_fields 296 297 if aPK_obj is not None: 298 self.__init_from_pk(aPK_obj=aPK_obj) 299 else: 300 self._init_from_row_data(row=row) 301 302 self._is_modified = False
303 #--------------------------------------------------------
304 - def __init_from_pk(self, aPK_obj=None):
305 """Creates a new clinical item instance by its PK. 306 307 aPK_obj can be: 308 - a simple value 309 * the primary key WHERE condition must be 310 a simple column 311 - a dictionary of values 312 * the primary key where condition must be a 313 subselect consuming the dict and producing 314 the single-value primary key 315 """ 316 self.pk_obj = aPK_obj 317 result = self.refetch_payload() 318 if result is True: 319 self.original_payload = {} 320 for field in self._idx.keys(): 321 self.original_payload[field] = self._payload[self._idx[field]] 322 return True 323 324 if result is False: 325 raise gmExceptions.ConstructorError, "[%s:%s]: error loading instance" % (self.__class__.__name__, self.pk_obj)
326 #--------------------------------------------------------
327 - def _init_from_row_data(self, row=None):
328 """Creates a new clinical item instance given its fields. 329 330 row must be a dict with the fields: 331 - pk_field: the name of the primary key field 332 - idx: a dict mapping field names to position 333 - data: the field values in a list (as returned by 334 cursor.fetchone() in the DB-API) 335 336 row = {'data': row, 'idx': idx, 'pk_field': 'the PK column name'} 337 338 rows, idx = gmPG2.run_ro_queries(queries = [{'cmd': cmd, 'args': args}], get_col_idx = True) 339 objects = [ cChildClass(row = {'data': r, 'idx': idx, 'pk_field': 'the PK column name'}) for r in rows ] 340 """ 341 try: 342 self._idx = row['idx'] 343 self._payload = row['data'] 344 self.pk_obj = self._payload[self._idx[row['pk_field']]] 345 except: 346 _log.exception('faulty <row> argument structure: %s' % row) 347 raise gmExceptions.ConstructorError, "[%s:??]: error loading instance from row data" % self.__class__.__name__ 348 349 if len(self._idx.keys()) != len(self._payload): 350 _log.critical('field index vs. payload length mismatch: %s field names vs. %s fields' % (len(self._idx.keys()), len(self._payload))) 351 _log.critical('faulty <row> argument structure: %s' % row) 352 raise gmExceptions.ConstructorError, "[%s:??]: error loading instance from row data" % self.__class__.__name__ 353 354 self.original_payload = {} 355 for field in self._idx.keys(): 356 self.original_payload[field] = self._payload[self._idx[field]]
357 #--------------------------------------------------------
358 - def __del__(self):
359 if self.__dict__.has_key('_is_modified'): 360 if self._is_modified: 361 _log.critical('[%s:%s]: loosing payload changes' % (self.__class__.__name__, self.pk_obj)) 362 _log.debug('original: %s' % self.original_payload) 363 _log.debug('modified: %s' % self._payload)
364 #--------------------------------------------------------
365 - def __str__(self):
366 tmp = [] 367 try: 368 for attr in self._idx.keys(): 369 if self._payload[self._idx[attr]] is None: 370 tmp.append(u'%s: NULL' % attr) 371 else: 372 tmp.append('%s: >>%s<<' % (attr, self._payload[self._idx[attr]])) 373 return '[%s:%s]: %s' % (self.__class__.__name__, self.pk_obj, str(tmp)) 374 except: 375 return 'nascent [%s @ %s], cannot show payload and primary key' %(self.__class__.__name__, id(self))
376 #--------------------------------------------------------
377 - def __getitem__(self, attribute):
378 # use try: except: as it is faster and we want this as fast as possible 379 380 # 1) backend payload cache 381 try: 382 return self._payload[self._idx[attribute]] 383 except KeyError: 384 pass 385 386 # 2) extension method results ... 387 getter = getattr(self, 'get_%s' % attribute, None) 388 if not callable(getter): 389 _log.warning('[%s]: no attribute [%s]' % (self.__class__.__name__, attribute)) 390 _log.warning('[%s]: valid attributes: %s' % (self.__class__.__name__, str(self._idx.keys()))) 391 _log.warning('[%s]: no getter method [get_%s]' % (self.__class__.__name__, attribute)) 392 methods = filter(lambda x: x[0].startswith('get_'), inspect.getmembers(self, inspect.ismethod)) 393 _log.warning('[%s]: valid getter methods: %s' % (self.__class__.__name__, str(methods))) 394 raise KeyError('[%s]: cannot read from key [%s]' % (self.__class__.__name__, attribute)) 395 396 self._ext_cache[attribute] = getter() 397 return self._ext_cache[attribute]
398 #--------------------------------------------------------
399 - def __setitem__(self, attribute, value):
400 401 # 1) backend payload cache 402 if attribute in self.__class__._updatable_fields: 403 try: 404 if self._payload[self._idx[attribute]] != value: 405 self._payload[self._idx[attribute]] = value 406 self._is_modified = True 407 return 408 except KeyError: 409 _log.warning('[%s]: cannot set attribute <%s> despite marked settable' % (self.__class__.__name__, attribute)) 410 _log.warning('[%s]: supposedly settable attributes: %s' % (self.__class__.__name__, str(self.__class__._updatable_fields))) 411 raise KeyError('[%s]: cannot write to key [%s]' % (self.__class__.__name__, attribute)) 412 413 # 2) setters providing extensions 414 if hasattr(self, 'set_%s' % attribute): 415 setter = getattr(self, "set_%s" % attribute) 416 if not callable(setter): 417 raise AttributeError('[%s] setter [set_%s] not callable' % (self.__class__.__name__, attribute)) 418 try: 419 del self._ext_cache[attribute] 420 except KeyError: 421 pass 422 if type(value) is types.TupleType: 423 if setter(*value): 424 self._is_modified = True 425 return 426 raise AttributeError('[%s]: setter [%s] failed for [%s]' % (self.__class__.__name__, setter, value)) 427 if setter(value): 428 self._is_modified = True 429 return 430 431 # 3) don't know what to do with <attribute> 432 _log.error('[%s]: cannot find attribute <%s> or setter method [set_%s]' % (self.__class__.__name__, attribute, attribute)) 433 _log.warning('[%s]: settable attributes: %s' % (self.__class__.__name__, str(self.__class__._updatable_fields))) 434 methods = filter(lambda x: x[0].startswith('set_'), inspect.getmembers(self, inspect.ismethod)) 435 _log.warning('[%s]: valid setter methods: %s' % (self.__class__.__name__, str(methods))) 436 raise AttributeError('[%s]: cannot set [%s]' % (self.__class__.__name__, attribute))
437 #-------------------------------------------------------- 438 # external API 439 #--------------------------------------------------------
440 - def same_payload(self, another_object=None):
441 raise NotImplementedError('comparison between [%s] and [%s] not implemented' % (self, another_object))
442 #--------------------------------------------------------
443 - def is_modified(self):
444 return self._is_modified
445 #--------------------------------------------------------
446 - def get_fields(self):
447 try: 448 return self._idx.keys() 449 except AttributeError: 450 return 'nascent [%s @ %s], cannot return keys' %(self.__class__.__name__, id(self))
451 #--------------------------------------------------------
452 - def get_updatable_fields(self):
453 return self.__class__._updatable_fields
454 #--------------------------------------------------------
455 - def fields_as_dict(self, date_format='%c', none_string=u'', escape_style=None, bool_strings=None):
456 if bool_strings is None: 457 bools = {True: u'true', False: u'false'} 458 else: 459 bools = {True: bool_strings[0], False: bool_strings[1]} 460 data = {} 461 for field in self._idx.keys(): 462 # FIXME: harden against BYTEA fields 463 #if type(self._payload[self._idx[field]]) == ... 464 # data[field] = _('<%s bytes of binary data>') % len(self._payload[self._idx[field]]) 465 # continue 466 val = self._payload[self._idx[field]] 467 if val is None: 468 data[field] = none_string 469 continue 470 if isinstance(val, bool): 471 data[field] = bools[val] 472 continue 473 if isinstance(val, datetime.datetime): 474 try: 475 data[field] = val.strftime(date_format).decode('utf8', 'replace') 476 except ValueError: 477 data[field] = val.isoformat() 478 if escape_style in [u'latex', u'tex']: 479 data[field] = tex_escape_string(data[field]) 480 continue 481 try: 482 data[field] = unicode(val, encoding = 'utf8', errors = 'replace') 483 except TypeError: 484 try: 485 data[field] = unicode(val) 486 except (UnicodeDecodeError, TypeError): 487 val = '%s' % str(val) 488 data[field] = val.decode('utf8', 'replace') 489 if escape_style in [u'latex', u'tex']: 490 data[field] = tex_escape_string(data[field]) 491 492 return data
493 #--------------------------------------------------------
494 - def get_patient(self):
495 _log.error('[%s:%s]: forgot to override get_patient()' % (self.__class__.__name__, self.pk_obj)) 496 return None
497 #--------------------------------------------------------
498 - def format(self):
499 return u'%s' % self
500 #--------------------------------------------------------
501 - def refetch_payload(self, ignore_changes=False):
502 """Fetch field values from backend. 503 """ 504 if self._is_modified: 505 if ignore_changes: 506 _log.critical('[%s:%s]: loosing payload changes' % (self.__class__.__name__, self.pk_obj)) 507 _log.debug('original: %s' % self.original_payload) 508 _log.debug('modified: %s' % self._payload) 509 else: 510 _log.critical('[%s:%s]: cannot reload, payload changed' % (self.__class__.__name__, self.pk_obj)) 511 return False 512 513 if type(self.pk_obj) == types.DictType: 514 arg = self.pk_obj 515 else: 516 arg = [self.pk_obj] 517 rows, self._idx = gmPG2.run_ro_queries ( 518 queries = [{'cmd': self.__class__._cmd_fetch_payload, 'args': arg}], 519 get_col_idx = True 520 ) 521 if len(rows) == 0: 522 _log.error('[%s:%s]: no such instance' % (self.__class__.__name__, self.pk_obj)) 523 return False 524 self._payload = rows[0] 525 return True
526 #--------------------------------------------------------
527 - def __noop(self):
528 pass
529 #--------------------------------------------------------
530 - def save(self, conn=None):
531 return self.save_payload(conn = conn)
532 #--------------------------------------------------------
533 - def save_payload(self, conn=None):
534 """Store updated values (if any) in database. 535 536 Optionally accepts a pre-existing connection 537 - returns a tuple (<True|False>, <data>) 538 - True: success 539 - False: an error occurred 540 * data is (error, message) 541 * for error meanings see gmPG2.run_rw_queries() 542 """ 543 if not self._is_modified: 544 return (True, None) 545 546 args = {} 547 for field in self._idx.keys(): 548 args[field] = self._payload[self._idx[field]] 549 self.modified_payload = args 550 551 close_conn = self.__noop 552 if conn is None: 553 conn = gmPG2.get_connection(readonly=False) 554 close_conn = conn.close 555 556 # query succeeded but failed to find the row to lock 557 # because another transaction committed an UPDATE or 558 # DELETE *before* we attempted to lock it ... 559 # FIXME: this can fail if savepoints are used since subtransactions change the xmin/xmax ... 560 561 queries = [] 562 for query in self.__class__._cmds_store_payload: 563 queries.append({'cmd': query, 'args': args}) 564 rows, idx = gmPG2.run_rw_queries ( 565 link_obj = conn, 566 queries = queries, 567 return_data = True, 568 get_col_idx = True 569 ) 570 571 # this can happen if: 572 # - someone else updated the row so XMIN does not match anymore 573 # - the PK went away (rows was deleted from under us) 574 # - another WHERE condition of the UPDATE did not produce any rows to update 575 if len(rows) == 0: 576 return (False, (u'cannot update row', _('[%s:%s]: row not updated (nothing returned), row in use ?') % (self.__class__.__name__, self.pk_obj))) 577 578 # update cached XMIN values (should be in first-and-only result row of last query) 579 row = rows[0] 580 for key in idx: 581 try: 582 self._payload[self._idx[key]] = row[idx[key]] 583 except KeyError: 584 conn.rollback() 585 close_conn() 586 _log.error('[%s:%s]: cannot update instance, XMIN refetch key mismatch on [%s]' % (self.__class__.__name__, self.pk_obj, key)) 587 _log.error('payload keys: %s' % str(self._idx)) 588 _log.error('XMIN refetch keys: %s' % str(idx)) 589 _log.error(args) 590 raise 591 592 conn.commit() 593 close_conn() 594 595 self._is_modified = False 596 # update to new "original" payload 597 self.original_payload = {} 598 for field in self._idx.keys(): 599 self.original_payload[field] = self._payload[self._idx[field]] 600 601 return (True, None)
602 603 #============================================================
604 -def jsonclasshintify(obj):
605 # this should eventually be somewhere else 606 """ turn the data into a list of dicts, adding "class hints". 607 all objects get turned into dictionaries which the other end 608 will interpret as "object", via the __jsonclass__ hint, 609 as specified by the JSONRPC protocol standard. 610 """ 611 if isinstance(obj, list): 612 return map(jsonclasshintify, obj) 613 elif isinstance(obj, gmPG2.dbapi.tz.FixedOffsetTimezone): 614 # this will get decoded as "from jsonobjproxy import {clsname}" 615 # at the remote (client) end. 616 res = {'__jsonclass__': ["jsonobjproxy.FixedOffsetTimezone"]} 617 res['name'] = obj._name 618 res['offset'] = jsonclasshintify(obj._offset) 619 return res 620 elif isinstance(obj, datetime.timedelta): 621 # this will get decoded as "from jsonobjproxy import {clsname}" 622 # at the remote (client) end. 623 res = {'__jsonclass__': ["jsonobjproxy.TimeDelta"]} 624 res['days'] = obj.days 625 res['seconds'] = obj.seconds 626 res['microseconds'] = obj.microseconds 627 return res 628 elif isinstance(obj, datetime.time): 629 # this will get decoded as "from jsonobjproxy import {clsname}" 630 # at the remote (client) end. 631 res = {'__jsonclass__': ["jsonobjproxy.Time"]} 632 res['hour'] = obj.hour 633 res['minute'] = obj.minute 634 res['second'] = obj.second 635 res['microsecond'] = obj.microsecond 636 res['tzinfo'] = jsonclasshintify(obj.tzinfo) 637 return res 638 elif isinstance(obj, datetime.datetime): 639 # this will get decoded as "from jsonobjproxy import {clsname}" 640 # at the remote (client) end. 641 res = {'__jsonclass__': ["jsonobjproxy.DateTime"]} 642 res['year'] = obj.year 643 res['month'] = obj.month 644 res['day'] = obj.day 645 res['hour'] = obj.hour 646 res['minute'] = obj.minute 647 res['second'] = obj.second 648 res['microsecond'] = obj.microsecond 649 res['tzinfo'] = jsonclasshintify(obj.tzinfo) 650 return res 651 elif isinstance(obj, cBusinessDBObject): 652 # this will get decoded as "from jsonobjproxy import {clsname}" 653 # at the remote (client) end. 654 res = {'__jsonclass__': ["jsonobjproxy.%s" % obj.__class__.__name__]} 655 for k in obj.get_fields(): 656 t = jsonclasshintify(obj[k]) 657 res[k] = t 658 print "props", res, dir(obj) 659 for attribute in dir(obj): 660 if not attribute.startswith("get_"): 661 continue 662 k = attribute[4:] 663 if res.has_key(k): 664 continue 665 getter = getattr(obj, attribute, None) 666 if callable(getter): 667 res[k] = jsonclasshintify(getter()) 668 return res 669 return obj
670 671 #============================================================ 672 if __name__ == '__main__': 673 674 if len(sys.argv) < 2: 675 sys.exit() 676 677 if sys.argv[1] != u'test': 678 sys.exit() 679 680 #--------------------------------------------------------
681 - class cTestObj(cBusinessDBObject):
682 _cmd_fetch_payload = None 683 _cmds_store_payload = None 684 _updatable_fields = [] 685 #----------------------------------------------------
686 - def get_something(self):
687 pass
688 #----------------------------------------------------
689 - def set_something(self):
690 pass
691 #-------------------------------------------------------- 692 from Gnumed.pycommon import gmI18N 693 gmI18N.activate_locale() 694 gmI18N.install_domain() 695 696 data = { 697 'pk_field': 'bogus_pk', 698 'idx': {'bogus_pk': 0, 'bogus_field': 1, 'bogus_date': 2}, 699 'data': [-1, 'bogus_data', datetime.datetime.now()] 700 } 701 obj = cTestObj(row=data) 702 #print obj['wrong_field'] 703 #print jsonclasshintify(obj) 704 #obj['wrong_field'] = 1 705 print obj.fields_as_dict() 706 707 #============================================================ 708