Package Gnumed :: Package pycommon :: Module gmBusinessDBObject
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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  __version__ = "$Revision: 1.60 $" 
129  __author__ = "K.Hilbert <Karsten.Hilbert@gmx.net>" 
130  __license__ = "GPL" 
131   
132  import sys, copy, types, inspect, logging, datetime 
133   
134   
135  if __name__ == '__main__': 
136          sys.path.insert(0, '../../') 
137  from Gnumed.pycommon import gmExceptions, gmPG2 
138   
139   
140  _log = logging.getLogger('gm.db') 
141  _log.info(__version__) 
142  #============================================================ 
143 -class cBusinessDBObject(object):
144 """Represents business objects in the database. 145 146 Rules: 147 - instances ARE ASSUMED TO EXIST in the database 148 - PK construction (aPK_obj): DOES verify its existence on instantiation 149 (fetching data fails) 150 - Row construction (row): allowed by using a dict of pairs 151 field name: field value (PERFORMANCE improvement) 152 - does NOT verify FK target existence 153 - does NOT create new entries in the database 154 - does NOT lazy-fetch fields on access 155 156 Class scope SQL commands and variables: 157 158 <_cmd_fetch_payload> 159 - must return exactly one row 160 - where clause argument values are expected 161 in self.pk_obj (taken from __init__(aPK_obj)) 162 - must return xmin of all rows that _cmds_store_payload 163 will be updating, so views must support the xmin columns 164 of their underlying tables 165 166 <_cmds_store_payload> 167 - one or multiple "update ... set ... where xmin_* = ..." statements 168 which actually update the database from the data in self._payload, 169 - the last query must refetch at least the XMIN values needed to detect 170 concurrent updates, their field names had better be the same as 171 in _cmd_fetch_payload, 172 - when subclasses tend to live a while after save_payload() was 173 called and they support computed fields (say, _(some_column) 174 you need to return *all* columns (see cEncounter) 175 176 <_updatable_fields> 177 - a list of fields available for update via object['field'] 178 179 180 A template for new child classes: 181 182 *********** start of template *********** 183 184 #------------------------------------------------------------ 185 from Gnumed.pycommon import gmBusinessDBObject 186 from Gnumed.pycommon import gmPG2 187 188 #============================================================ 189 # short description 190 #------------------------------------------------------------ 191 # use plural form, search-replace get_XXX 192 _SQL_get_XXX = u\""" 193 SELECT *, (xmin AS xmin_XXX) 194 FROM XXX.v_XXX 195 WHERE %s 196 \""" 197 198 class cXxxXxx(gmBusinessDBObject.cBusinessDBObject): 199 \"""Represents ...\""" 200 201 _cmd_fetch_payload = _SQL_get_XXX % u"pk_XXX = %s" 202 _cmds_store_payload = [ 203 u\""" 204 UPDATE xxx.xxx SET -- typically the underlying table name 205 xxx = %(xxx)s, -- typically "table_col = %(view_col)s" 206 xxx = gm.nullify_empty_string(%(xxx)s) 207 WHERE 208 pk = %(pk_XXX)s 209 AND 210 xmin = %(xmin_XXX)s 211 RETURNING 212 pk as pk_XXX, 213 xmin as xmin_XXX 214 \""" 215 ] 216 # view columns that can be updated: 217 _updatable_fields = [ 218 u'xxx', 219 u'xxx' 220 ] 221 #------------------------------------------------------------ 222 def get_XXX(order_by=None): 223 if order_by is None: 224 order_by = u'true' 225 else: 226 order_by = u'true ORDER BY %s' % order_by 227 228 cmd = _SQL_get_XXX % order_by 229 rows, idx = gmPG2.run_ro_queries(queries = [{'cmd': cmd}], get_col_idx = True) 230 return [ cXxxXxx(row = {'data': r, 'idx': idx, 'pk_field': 'xxx'}) for r in rows ] 231 #------------------------------------------------------------ 232 def create_xxx(xxx=None, xxx=None): 233 234 args = { 235 u'xxx': xxx, 236 u'xxx': xxx 237 } 238 cmd = u\""" 239 INSERT INTO xxx.xxx ( 240 xxx, 241 xxx, 242 xxx 243 ) VALUES ( 244 %(xxx)s, 245 %(xxx)s, 246 gm.nullify_empty_string(%(xxx)s) 247 ) 248 RETURNING pk 249 \""" 250 rows, idx = gmPG2.run_rw_queries(queries = [{'cmd': cmd, 'args': args}], return_data = True, get_col_idx = False) 251 252 return cXxxXxx(aPK_obj = rows[0]['pk']) 253 #------------------------------------------------------------ 254 def delete_xxx(xxx=None): 255 args = {'pk': xxx} 256 cmd = u"DELETE FROM xxx.xxx WHERE pk = %(pk)s" 257 gmPG2.run_rw_queries(queries = [{'cmd': cmd, 'args': args}]) 258 return True 259 #------------------------------------------------------------ 260 261 *********** end of template *********** 262 263 """ 264 #--------------------------------------------------------
265 - def __init__(self, aPK_obj=None, row=None):
266 """Init business object. 267 268 Call from child classes: 269 270 super(cChildClass, self).__init__(aPK_obj = aPK_obj, row = row) 271 """ 272 # initialize those "too early" because checking descendants might 273 # fail which will then call __str__ in stack trace logging if --debug 274 # was given which in turn needs those instance variables 275 self.pk_obj = '<uninitialized>' 276 self._idx = {} 277 self._payload = [] # the cache for backend object values (mainly table fields) 278 self._ext_cache = {} # the cache for extended method's results 279 self._is_modified = False 280 281 # check descendants 282 self.__class__._cmd_fetch_payload 283 self.__class__._cmds_store_payload 284 self.__class__._updatable_fields 285 286 if aPK_obj is not None: 287 self.__init_from_pk(aPK_obj=aPK_obj) 288 else: 289 self._init_from_row_data(row=row) 290 291 self._is_modified = False
292 #--------------------------------------------------------
293 - def __init_from_pk(self, aPK_obj=None):
294 """Creates a new clinical item instance by its PK. 295 296 aPK_obj can be: 297 - a simple value 298 * the primary key WHERE condition must be 299 a simple column 300 - a dictionary of values 301 * the primary key where condition must be a 302 subselect consuming the dict and producing 303 the single-value primary key 304 """ 305 self.pk_obj = aPK_obj 306 result = self.refetch_payload() 307 if result is True: 308 self.original_payload = {} 309 for field in self._idx.keys(): 310 self.original_payload[field] = self._payload[self._idx[field]] 311 return True 312 313 if result is False: 314 raise gmExceptions.ConstructorError, "[%s:%s]: error loading instance" % (self.__class__.__name__, self.pk_obj)
315 #--------------------------------------------------------
316 - def _init_from_row_data(self, row=None):
317 """Creates a new clinical item instance given its fields. 318 319 row must be a dict with the fields: 320 - pk_field: the name of the primary key field 321 - idx: a dict mapping field names to position 322 - data: the field values in a list (as returned by 323 cursor.fetchone() in the DB-API) 324 325 row = {'data': row, 'idx': idx, 'pk_field': 'the PK column name'} 326 327 rows, idx = gmPG2.run_ro_queries(queries = [{'cmd': cmd, 'args': args}], get_col_idx = True) 328 objects = [ cChildClass(row = {'data': r, 'idx': idx, 'pk_field': 'the PK column name'}) for r in rows ] 329 """ 330 try: 331 self._idx = row['idx'] 332 self._payload = row['data'] 333 self.pk_obj = self._payload[self._idx[row['pk_field']]] 334 except: 335 _log.exception('faulty <row> argument structure: %s' % row) 336 raise gmExceptions.ConstructorError, "[%s:??]: error loading instance from row data" % self.__class__.__name__ 337 338 if len(self._idx.keys()) != len(self._payload): 339 _log.critical('field index vs. payload length mismatch: %s field names vs. %s fields' % (len(self._idx.keys()), len(self._payload))) 340 _log.critical('faulty <row> argument structure: %s' % row) 341 raise gmExceptions.ConstructorError, "[%s:??]: error loading instance from row data" % self.__class__.__name__ 342 343 self.original_payload = {} 344 for field in self._idx.keys(): 345 self.original_payload[field] = self._payload[self._idx[field]]
346 #--------------------------------------------------------
347 - def __del__(self):
348 if self.__dict__.has_key('_is_modified'): 349 if self._is_modified: 350 _log.critical('[%s:%s]: loosing payload changes' % (self.__class__.__name__, self.pk_obj)) 351 _log.debug('original: %s' % self.original_payload) 352 _log.debug('modified: %s' % self._payload)
353 #--------------------------------------------------------
354 - def __str__(self):
355 tmp = [] 356 try: 357 for attr in self._idx.keys(): 358 if self._payload[self._idx[attr]] is None: 359 tmp.append(u'%s: NULL' % attr) 360 else: 361 tmp.append('%s: >>%s<<' % (attr, self._payload[self._idx[attr]])) 362 return '[%s:%s]: %s' % (self.__class__.__name__, self.pk_obj, str(tmp)) 363 except: 364 return 'nascent [%s @ %s], cannot show payload and primary key' %(self.__class__.__name__, id(self))
365 #--------------------------------------------------------
366 - def __getitem__(self, attribute):
367 # use try: except: as it is faster and we want this as fast as possible 368 369 # 1) backend payload cache 370 try: 371 return self._payload[self._idx[attribute]] 372 except KeyError: 373 pass 374 375 # 2) extension method results ... 376 getter = getattr(self, 'get_%s' % attribute, None) 377 if not callable(getter): 378 _log.warning('[%s]: no attribute [%s]' % (self.__class__.__name__, attribute)) 379 _log.warning('[%s]: valid attributes: %s' % (self.__class__.__name__, str(self._idx.keys()))) 380 _log.warning('[%s]: no getter method [get_%s]' % (self.__class__.__name__, attribute)) 381 methods = filter(lambda x: x[0].startswith('get_'), inspect.getmembers(self, inspect.ismethod)) 382 _log.warning('[%s]: valid getter methods: %s' % (self.__class__.__name__, str(methods))) 383 raise KeyError('[%s]: cannot read from key [%s]' % (self.__class__.__name__, attribute)) 384 385 self._ext_cache[attribute] = getter() 386 return self._ext_cache[attribute]
387 #--------------------------------------------------------
388 - def __setitem__(self, attribute, value):
389 390 # 1) backend payload cache 391 if attribute in self.__class__._updatable_fields: 392 try: 393 if self._payload[self._idx[attribute]] != value: 394 self._payload[self._idx[attribute]] = value 395 self._is_modified = True 396 return 397 except KeyError: 398 _log.warning('[%s]: cannot set attribute <%s> despite marked settable' % (self.__class__.__name__, attribute)) 399 _log.warning('[%s]: supposedly settable attributes: %s' % (self.__class__.__name__, str(self.__class__._updatable_fields))) 400 raise KeyError('[%s]: cannot write to key [%s]' % (self.__class__.__name__, attribute)) 401 402 # 2) setters providing extensions 403 if hasattr(self, 'set_%s' % attribute): 404 setter = getattr(self, "set_%s" % attribute) 405 if not callable(setter): 406 raise AttributeError('[%s] setter [set_%s] not callable' % (self.__class__.__name__, attribute)) 407 try: 408 del self._ext_cache[attribute] 409 except KeyError: 410 pass 411 if type(value) is types.TupleType: 412 if setter(*value): 413 self._is_modified = True 414 return 415 raise AttributeError('[%s]: setter [%s] failed for [%s]' % (self.__class__.__name__, setter, value)) 416 if setter(value): 417 self._is_modified = True 418 return 419 420 # 3) don't know what to do with <attribute> 421 _log.error('[%s]: cannot find attribute <%s> or setter method [set_%s]' % (self.__class__.__name__, attribute, attribute)) 422 _log.warning('[%s]: settable attributes: %s' % (self.__class__.__name__, str(self.__class__._updatable_fields))) 423 methods = filter(lambda x: x[0].startswith('set_'), inspect.getmembers(self, inspect.ismethod)) 424 _log.warning('[%s]: valid setter methods: %s' % (self.__class__.__name__, str(methods))) 425 raise AttributeError('[%s]: cannot set [%s]' % (self.__class__.__name__, attribute))
426 #-------------------------------------------------------- 427 # external API 428 #--------------------------------------------------------
429 - def same_payload(self, another_object=None):
430 raise NotImplementedError('comparison between [%s] and [%s] not implemented' % (self, another_object))
431 #--------------------------------------------------------
432 - def is_modified(self):
433 return self._is_modified
434 #--------------------------------------------------------
435 - def get_fields(self):
436 try: 437 return self._idx.keys() 438 except AttributeError: 439 return 'nascent [%s @ %s], cannot return keys' %(self.__class__.__name__, id(self))
440 #--------------------------------------------------------
441 - def get_updatable_fields(self):
442 return self.__class__._updatable_fields
443 #--------------------------------------------------------
444 - def fields_as_dict(self, date_format='%c'):
445 data = {} 446 for field in self._idx.keys(): 447 val = self._payload[self._idx[field]] 448 if val is None: 449 data[field] = u'' 450 continue 451 if isinstance(val, datetime.datetime): 452 try: 453 data[field] = val.strftime(date_format).decode('utf8', 'replace') 454 except ValueError: 455 data[field] = val.isoformat() 456 continue 457 try: 458 data[field] = unicode(val, encoding = 'utf8', errors = 'replace') 459 except TypeError: 460 try: 461 data[field] = unicode(val) 462 except (UnicodeDecodeError, TypeError): 463 val = '%s' % str(val) 464 data[field] = val.decode('utf8', 'replace') 465 return data
466 #--------------------------------------------------------
467 - def get_patient(self):
468 _log.error('[%s:%s]: forgot to override get_patient()' % (self.__class__.__name__, self.pk_obj)) 469 return None
470 #--------------------------------------------------------
471 - def refetch_payload(self, ignore_changes=False):
472 """Fetch field values from backend. 473 """ 474 if self._is_modified: 475 if ignore_changes: 476 _log.critical('[%s:%s]: loosing payload changes' % (self.__class__.__name__, self.pk_obj)) 477 _log.debug('original: %s' % self.original_payload) 478 _log.debug('modified: %s' % self._payload) 479 else: 480 _log.critical('[%s:%s]: cannot reload, payload changed' % (self.__class__.__name__, self.pk_obj)) 481 return False 482 483 if type(self.pk_obj) == types.DictType: 484 arg = self.pk_obj 485 else: 486 arg = [self.pk_obj] 487 rows, self._idx = gmPG2.run_ro_queries ( 488 queries = [{'cmd': self.__class__._cmd_fetch_payload, 'args': arg}], 489 get_col_idx = True 490 ) 491 if len(rows) == 0: 492 _log.error('[%s:%s]: no such instance' % (self.__class__.__name__, self.pk_obj)) 493 return False 494 self._payload = rows[0] 495 return True
496 #--------------------------------------------------------
497 - def __noop(self):
498 pass
499 #--------------------------------------------------------
500 - def save(self, conn=None):
501 return self.save_payload(conn = conn)
502 #--------------------------------------------------------
503 - def save_payload(self, conn=None):
504 """Store updated values (if any) in database. 505 506 Optionally accepts a pre-existing connection 507 - returns a tuple (<True|False>, <data>) 508 - True: success 509 - False: an error occurred 510 * data is (error, message) 511 * for error meanings see gmPG2.run_rw_queries() 512 """ 513 if not self._is_modified: 514 return (True, None) 515 516 args = {} 517 for field in self._idx.keys(): 518 args[field] = self._payload[self._idx[field]] 519 self.modified_payload = args 520 521 close_conn = self.__noop 522 if conn is None: 523 conn = gmPG2.get_connection(readonly=False) 524 close_conn = conn.close 525 526 # query succeeded but failed to find the row to lock 527 # because another transaction committed an UPDATE or 528 # DELETE *before* we attempted to lock it ... 529 # FIXME: this can fail if savepoints are used since subtransactions change the xmin/xmax ... 530 531 queries = [] 532 for query in self.__class__._cmds_store_payload: 533 queries.append({'cmd': query, 'args': args}) 534 rows, idx = gmPG2.run_rw_queries ( 535 link_obj = conn, 536 queries = queries, 537 return_data = True, 538 get_col_idx = True 539 ) 540 541 # this can happen if: 542 # - someone else updated the row so XMIN does not match anymore 543 # - the PK went away (rows was deleted from under us) 544 # - another WHERE condition of the UPDATE did not produce any rows to update 545 if len(rows) == 0: 546 return (False, (u'cannot update row', _('[%s:%s]: row not updated (nothing returned), row in use ?') % (self.__class__.__name__, self.pk_obj))) 547 548 # update cached XMIN values (should be in first-and-only result row of last query) 549 row = rows[0] 550 for key in idx: 551 try: 552 self._payload[self._idx[key]] = row[idx[key]] 553 except KeyError: 554 conn.rollback() 555 close_conn() 556 _log.error('[%s:%s]: cannot update instance, XMIN refetch key mismatch on [%s]' % (self.__class__.__name__, self.pk_obj, key)) 557 _log.error('payload keys: %s' % str(self._idx)) 558 _log.error('XMIN refetch keys: %s' % str(idx)) 559 _log.error(args) 560 raise 561 562 conn.commit() 563 close_conn() 564 565 self._is_modified = False 566 # update to new "original" payload 567 self.original_payload = {} 568 for field in self._idx.keys(): 569 self.original_payload[field] = self._payload[self._idx[field]] 570 571 return (True, None)
572 573 #============================================================
574 -def jsonclasshintify(obj):
575 # this should eventually be somewhere else 576 """ turn the data into a list of dicts, adding "class hints". 577 all objects get turned into dictionaries which the other end 578 will interpret as "object", via the __jsonclass__ hint, 579 as specified by the JSONRPC protocol standard. 580 """ 581 if isinstance(obj, list): 582 return map(jsonclasshintify, obj) 583 elif isinstance(obj, gmPG2.dbapi.tz.FixedOffsetTimezone): 584 # this will get decoded as "from jsonobjproxy import {clsname}" 585 # at the remote (client) end. 586 res = {'__jsonclass__': ["jsonobjproxy.FixedOffsetTimezone"]} 587 res['name'] = obj._name 588 res['offset'] = jsonclasshintify(obj._offset) 589 return res 590 elif isinstance(obj, datetime.timedelta): 591 # this will get decoded as "from jsonobjproxy import {clsname}" 592 # at the remote (client) end. 593 res = {'__jsonclass__': ["jsonobjproxy.TimeDelta"]} 594 res['days'] = obj.days 595 res['seconds'] = obj.seconds 596 res['microseconds'] = obj.microseconds 597 return res 598 elif isinstance(obj, datetime.time): 599 # this will get decoded as "from jsonobjproxy import {clsname}" 600 # at the remote (client) end. 601 res = {'__jsonclass__': ["jsonobjproxy.Time"]} 602 res['hour'] = obj.hour 603 res['minute'] = obj.minute 604 res['second'] = obj.second 605 res['microsecond'] = obj.microsecond 606 res['tzinfo'] = jsonclasshintify(obj.tzinfo) 607 return res 608 elif isinstance(obj, datetime.datetime): 609 # this will get decoded as "from jsonobjproxy import {clsname}" 610 # at the remote (client) end. 611 res = {'__jsonclass__': ["jsonobjproxy.DateTime"]} 612 res['year'] = obj.year 613 res['month'] = obj.month 614 res['day'] = obj.day 615 res['hour'] = obj.hour 616 res['minute'] = obj.minute 617 res['second'] = obj.second 618 res['microsecond'] = obj.microsecond 619 res['tzinfo'] = jsonclasshintify(obj.tzinfo) 620 return res 621 elif isinstance(obj, cBusinessDBObject): 622 # this will get decoded as "from jsonobjproxy import {clsname}" 623 # at the remote (client) end. 624 res = {'__jsonclass__': ["jsonobjproxy.%s" % obj.__class__.__name__]} 625 for k in obj.get_fields(): 626 t = jsonclasshintify(obj[k]) 627 res[k] = t 628 print "props", res, dir(obj) 629 for attribute in dir(obj): 630 if not attribute.startswith("get_"): 631 continue 632 k = attribute[4:] 633 if res.has_key(k): 634 continue 635 getter = getattr(obj, attribute, None) 636 if callable(getter): 637 res[k] = jsonclasshintify(getter()) 638 return res 639 return obj
640 641 #============================================================ 642 if __name__ == '__main__': 643 644 if len(sys.argv) < 2: 645 sys.exit() 646 647 if sys.argv[1] != u'test': 648 sys.exit() 649 650 #--------------------------------------------------------
651 - class cTestObj(cBusinessDBObject):
652 _cmd_fetch_payload = None 653 _cmds_store_payload = None 654 _updatable_fields = [] 655 #----------------------------------------------------
656 - def get_something(self):
657 pass
658 #----------------------------------------------------
659 - def set_something(self):
660 pass
661 #-------------------------------------------------------- 662 from Gnumed.pycommon import gmI18N 663 gmI18N.activate_locale() 664 gmI18N.install_domain() 665 666 data = { 667 'pk_field': 'bogus_pk', 668 'idx': {'bogus_pk': 0, 'bogus_field': 1, 'bogus_date': 2}, 669 'data': [-1, 'bogus_data', datetime.datetime.now()] 670 } 671 obj = cTestObj(row=data) 672 #print obj['wrong_field'] 673 #print jsonclasshintify(obj) 674 #obj['wrong_field'] = 1 675 print obj.fields_as_dict() 676 677 #============================================================ 678