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 format(self): 223 return u'%s' % self 224 225 #------------------------------------------------------------ 226 def get_XXX(order_by=None): 227 if order_by is None: 228 order_by = u'true' 229 else: 230 order_by = u'true ORDER BY %s' % order_by 231 232 cmd = _SQL_get_XXX % order_by 233 rows, idx = gmPG2.run_ro_queries(queries = [{'cmd': cmd}], get_col_idx = True) 234 return [ cXxxXxx(row = {'data': r, 'idx': idx, 'pk_field': 'xxx'}) for r in rows ] 235 #------------------------------------------------------------ 236 def create_xxx(xxx=None, xxx=None): 237 238 args = { 239 u'xxx': xxx, 240 u'xxx': xxx 241 } 242 cmd = u\""" 243 INSERT INTO xxx.xxx ( 244 xxx, 245 xxx, 246 xxx 247 ) VALUES ( 248 %(xxx)s, 249 %(xxx)s, 250 gm.nullify_empty_string(%(xxx)s) 251 ) 252 RETURNING pk 253 \""" 254 rows, idx = gmPG2.run_rw_queries(queries = [{'cmd': cmd, 'args': args}], return_data = True, get_col_idx = False) 255 256 return cXxxXxx(aPK_obj = rows[0]['pk']) 257 #------------------------------------------------------------ 258 def delete_xxx(xxx=None): 259 args = {'pk': xxx} 260 cmd = u"DELETE FROM xxx.xxx WHERE pk = %(pk)s" 261 gmPG2.run_rw_queries(queries = [{'cmd': cmd, 'args': args}]) 262 return True 263 #------------------------------------------------------------ 264 265 *********** end of template *********** 266 267 """ 268 #--------------------------------------------------------
269 - def __init__(self, aPK_obj=None, row=None):
270 """Init business object. 271 272 Call from child classes: 273 274 super(cChildClass, self).__init__(aPK_obj = aPK_obj, row = row) 275 """ 276 # initialize those "too early" because checking descendants might 277 # fail which will then call __str__ in stack trace logging if --debug 278 # was given which in turn needs those instance variables 279 self.pk_obj = '<uninitialized>' 280 self._idx = {} 281 self._payload = [] # the cache for backend object values (mainly table fields) 282 self._ext_cache = {} # the cache for extended method's results 283 self._is_modified = False 284 285 # check descendants 286 self.__class__._cmd_fetch_payload 287 self.__class__._cmds_store_payload 288 self.__class__._updatable_fields 289 290 if aPK_obj is not None: 291 self.__init_from_pk(aPK_obj=aPK_obj) 292 else: 293 self._init_from_row_data(row=row) 294 295 self._is_modified = False
296 #--------------------------------------------------------
297 - def __init_from_pk(self, aPK_obj=None):
298 """Creates a new clinical item instance by its PK. 299 300 aPK_obj can be: 301 - a simple value 302 * the primary key WHERE condition must be 303 a simple column 304 - a dictionary of values 305 * the primary key where condition must be a 306 subselect consuming the dict and producing 307 the single-value primary key 308 """ 309 self.pk_obj = aPK_obj 310 result = self.refetch_payload() 311 if result is True: 312 self.original_payload = {} 313 for field in self._idx.keys(): 314 self.original_payload[field] = self._payload[self._idx[field]] 315 return True 316 317 if result is False: 318 raise gmExceptions.ConstructorError, "[%s:%s]: error loading instance" % (self.__class__.__name__, self.pk_obj)
319 #--------------------------------------------------------
320 - def _init_from_row_data(self, row=None):
321 """Creates a new clinical item instance given its fields. 322 323 row must be a dict with the fields: 324 - pk_field: the name of the primary key field 325 - idx: a dict mapping field names to position 326 - data: the field values in a list (as returned by 327 cursor.fetchone() in the DB-API) 328 329 row = {'data': row, 'idx': idx, 'pk_field': 'the PK column name'} 330 331 rows, idx = gmPG2.run_ro_queries(queries = [{'cmd': cmd, 'args': args}], get_col_idx = True) 332 objects = [ cChildClass(row = {'data': r, 'idx': idx, 'pk_field': 'the PK column name'}) for r in rows ] 333 """ 334 try: 335 self._idx = row['idx'] 336 self._payload = row['data'] 337 self.pk_obj = self._payload[self._idx[row['pk_field']]] 338 except: 339 _log.exception('faulty <row> argument structure: %s' % row) 340 raise gmExceptions.ConstructorError, "[%s:??]: error loading instance from row data" % self.__class__.__name__ 341 342 if len(self._idx.keys()) != len(self._payload): 343 _log.critical('field index vs. payload length mismatch: %s field names vs. %s fields' % (len(self._idx.keys()), len(self._payload))) 344 _log.critical('faulty <row> argument structure: %s' % row) 345 raise gmExceptions.ConstructorError, "[%s:??]: error loading instance from row data" % self.__class__.__name__ 346 347 self.original_payload = {} 348 for field in self._idx.keys(): 349 self.original_payload[field] = self._payload[self._idx[field]]
350 #--------------------------------------------------------
351 - def __del__(self):
352 if self.__dict__.has_key('_is_modified'): 353 if self._is_modified: 354 _log.critical('[%s:%s]: loosing payload changes' % (self.__class__.__name__, self.pk_obj)) 355 _log.debug('original: %s' % self.original_payload) 356 _log.debug('modified: %s' % self._payload)
357 #--------------------------------------------------------
358 - def __str__(self):
359 tmp = [] 360 try: 361 for attr in self._idx.keys(): 362 if self._payload[self._idx[attr]] is None: 363 tmp.append(u'%s: NULL' % attr) 364 else: 365 tmp.append('%s: >>%s<<' % (attr, self._payload[self._idx[attr]])) 366 return '[%s:%s]: %s' % (self.__class__.__name__, self.pk_obj, str(tmp)) 367 except: 368 return 'nascent [%s @ %s], cannot show payload and primary key' %(self.__class__.__name__, id(self))
369 #--------------------------------------------------------
370 - def __getitem__(self, attribute):
371 # use try: except: as it is faster and we want this as fast as possible 372 373 # 1) backend payload cache 374 try: 375 return self._payload[self._idx[attribute]] 376 except KeyError: 377 pass 378 379 # 2) extension method results ... 380 getter = getattr(self, 'get_%s' % attribute, None) 381 if not callable(getter): 382 _log.warning('[%s]: no attribute [%s]' % (self.__class__.__name__, attribute)) 383 _log.warning('[%s]: valid attributes: %s' % (self.__class__.__name__, str(self._idx.keys()))) 384 _log.warning('[%s]: no getter method [get_%s]' % (self.__class__.__name__, attribute)) 385 methods = filter(lambda x: x[0].startswith('get_'), inspect.getmembers(self, inspect.ismethod)) 386 _log.warning('[%s]: valid getter methods: %s' % (self.__class__.__name__, str(methods))) 387 raise KeyError('[%s]: cannot read from key [%s]' % (self.__class__.__name__, attribute)) 388 389 self._ext_cache[attribute] = getter() 390 return self._ext_cache[attribute]
391 #--------------------------------------------------------
392 - def __setitem__(self, attribute, value):
393 394 # 1) backend payload cache 395 if attribute in self.__class__._updatable_fields: 396 try: 397 if self._payload[self._idx[attribute]] != value: 398 self._payload[self._idx[attribute]] = value 399 self._is_modified = True 400 return 401 except KeyError: 402 _log.warning('[%s]: cannot set attribute <%s> despite marked settable' % (self.__class__.__name__, attribute)) 403 _log.warning('[%s]: supposedly settable attributes: %s' % (self.__class__.__name__, str(self.__class__._updatable_fields))) 404 raise KeyError('[%s]: cannot write to key [%s]' % (self.__class__.__name__, attribute)) 405 406 # 2) setters providing extensions 407 if hasattr(self, 'set_%s' % attribute): 408 setter = getattr(self, "set_%s" % attribute) 409 if not callable(setter): 410 raise AttributeError('[%s] setter [set_%s] not callable' % (self.__class__.__name__, attribute)) 411 try: 412 del self._ext_cache[attribute] 413 except KeyError: 414 pass 415 if type(value) is types.TupleType: 416 if setter(*value): 417 self._is_modified = True 418 return 419 raise AttributeError('[%s]: setter [%s] failed for [%s]' % (self.__class__.__name__, setter, value)) 420 if setter(value): 421 self._is_modified = True 422 return 423 424 # 3) don't know what to do with <attribute> 425 _log.error('[%s]: cannot find attribute <%s> or setter method [set_%s]' % (self.__class__.__name__, attribute, attribute)) 426 _log.warning('[%s]: settable attributes: %s' % (self.__class__.__name__, str(self.__class__._updatable_fields))) 427 methods = filter(lambda x: x[0].startswith('set_'), inspect.getmembers(self, inspect.ismethod)) 428 _log.warning('[%s]: valid setter methods: %s' % (self.__class__.__name__, str(methods))) 429 raise AttributeError('[%s]: cannot set [%s]' % (self.__class__.__name__, attribute))
430 #-------------------------------------------------------- 431 # external API 432 #--------------------------------------------------------
433 - def same_payload(self, another_object=None):
434 raise NotImplementedError('comparison between [%s] and [%s] not implemented' % (self, another_object))
435 #--------------------------------------------------------
436 - def is_modified(self):
437 return self._is_modified
438 #--------------------------------------------------------
439 - def get_fields(self):
440 try: 441 return self._idx.keys() 442 except AttributeError: 443 return 'nascent [%s @ %s], cannot return keys' %(self.__class__.__name__, id(self))
444 #--------------------------------------------------------
445 - def get_updatable_fields(self):
446 return self.__class__._updatable_fields
447 #--------------------------------------------------------
448 - def fields_as_dict(self, date_format='%c'):
449 data = {} 450 for field in self._idx.keys(): 451 val = self._payload[self._idx[field]] 452 if val is None: 453 data[field] = u'' 454 continue 455 if isinstance(val, datetime.datetime): 456 try: 457 data[field] = val.strftime(date_format).decode('utf8', 'replace') 458 except ValueError: 459 data[field] = val.isoformat() 460 continue 461 try: 462 data[field] = unicode(val, encoding = 'utf8', errors = 'replace') 463 except TypeError: 464 try: 465 data[field] = unicode(val) 466 except (UnicodeDecodeError, TypeError): 467 val = '%s' % str(val) 468 data[field] = val.decode('utf8', 'replace') 469 return data
470 #--------------------------------------------------------
471 - def get_patient(self):
472 _log.error('[%s:%s]: forgot to override get_patient()' % (self.__class__.__name__, self.pk_obj)) 473 return None
474 #--------------------------------------------------------
475 - def format(self):
476 return u'%s' % self
477 #--------------------------------------------------------
478 - def refetch_payload(self, ignore_changes=False):
479 """Fetch field values from backend. 480 """ 481 if self._is_modified: 482 if ignore_changes: 483 _log.critical('[%s:%s]: loosing payload changes' % (self.__class__.__name__, self.pk_obj)) 484 _log.debug('original: %s' % self.original_payload) 485 _log.debug('modified: %s' % self._payload) 486 else: 487 _log.critical('[%s:%s]: cannot reload, payload changed' % (self.__class__.__name__, self.pk_obj)) 488 return False 489 490 if type(self.pk_obj) == types.DictType: 491 arg = self.pk_obj 492 else: 493 arg = [self.pk_obj] 494 rows, self._idx = gmPG2.run_ro_queries ( 495 queries = [{'cmd': self.__class__._cmd_fetch_payload, 'args': arg}], 496 get_col_idx = True 497 ) 498 if len(rows) == 0: 499 _log.error('[%s:%s]: no such instance' % (self.__class__.__name__, self.pk_obj)) 500 return False 501 self._payload = rows[0] 502 return True
503 #--------------------------------------------------------
504 - def __noop(self):
505 pass
506 #--------------------------------------------------------
507 - def save(self, conn=None):
508 return self.save_payload(conn = conn)
509 #--------------------------------------------------------
510 - def save_payload(self, conn=None):
511 """Store updated values (if any) in database. 512 513 Optionally accepts a pre-existing connection 514 - returns a tuple (<True|False>, <data>) 515 - True: success 516 - False: an error occurred 517 * data is (error, message) 518 * for error meanings see gmPG2.run_rw_queries() 519 """ 520 if not self._is_modified: 521 return (True, None) 522 523 args = {} 524 for field in self._idx.keys(): 525 args[field] = self._payload[self._idx[field]] 526 self.modified_payload = args 527 528 close_conn = self.__noop 529 if conn is None: 530 conn = gmPG2.get_connection(readonly=False) 531 close_conn = conn.close 532 533 # query succeeded but failed to find the row to lock 534 # because another transaction committed an UPDATE or 535 # DELETE *before* we attempted to lock it ... 536 # FIXME: this can fail if savepoints are used since subtransactions change the xmin/xmax ... 537 538 queries = [] 539 for query in self.__class__._cmds_store_payload: 540 queries.append({'cmd': query, 'args': args}) 541 rows, idx = gmPG2.run_rw_queries ( 542 link_obj = conn, 543 queries = queries, 544 return_data = True, 545 get_col_idx = True 546 ) 547 548 # this can happen if: 549 # - someone else updated the row so XMIN does not match anymore 550 # - the PK went away (rows was deleted from under us) 551 # - another WHERE condition of the UPDATE did not produce any rows to update 552 if len(rows) == 0: 553 return (False, (u'cannot update row', _('[%s:%s]: row not updated (nothing returned), row in use ?') % (self.__class__.__name__, self.pk_obj))) 554 555 # update cached XMIN values (should be in first-and-only result row of last query) 556 row = rows[0] 557 for key in idx: 558 try: 559 self._payload[self._idx[key]] = row[idx[key]] 560 except KeyError: 561 conn.rollback() 562 close_conn() 563 _log.error('[%s:%s]: cannot update instance, XMIN refetch key mismatch on [%s]' % (self.__class__.__name__, self.pk_obj, key)) 564 _log.error('payload keys: %s' % str(self._idx)) 565 _log.error('XMIN refetch keys: %s' % str(idx)) 566 _log.error(args) 567 raise 568 569 conn.commit() 570 close_conn() 571 572 self._is_modified = False 573 # update to new "original" payload 574 self.original_payload = {} 575 for field in self._idx.keys(): 576 self.original_payload[field] = self._payload[self._idx[field]] 577 578 return (True, None)
579 580 #============================================================
581 -def jsonclasshintify(obj):
582 # this should eventually be somewhere else 583 """ turn the data into a list of dicts, adding "class hints". 584 all objects get turned into dictionaries which the other end 585 will interpret as "object", via the __jsonclass__ hint, 586 as specified by the JSONRPC protocol standard. 587 """ 588 if isinstance(obj, list): 589 return map(jsonclasshintify, obj) 590 elif isinstance(obj, gmPG2.dbapi.tz.FixedOffsetTimezone): 591 # this will get decoded as "from jsonobjproxy import {clsname}" 592 # at the remote (client) end. 593 res = {'__jsonclass__': ["jsonobjproxy.FixedOffsetTimezone"]} 594 res['name'] = obj._name 595 res['offset'] = jsonclasshintify(obj._offset) 596 return res 597 elif isinstance(obj, datetime.timedelta): 598 # this will get decoded as "from jsonobjproxy import {clsname}" 599 # at the remote (client) end. 600 res = {'__jsonclass__': ["jsonobjproxy.TimeDelta"]} 601 res['days'] = obj.days 602 res['seconds'] = obj.seconds 603 res['microseconds'] = obj.microseconds 604 return res 605 elif isinstance(obj, datetime.time): 606 # this will get decoded as "from jsonobjproxy import {clsname}" 607 # at the remote (client) end. 608 res = {'__jsonclass__': ["jsonobjproxy.Time"]} 609 res['hour'] = obj.hour 610 res['minute'] = obj.minute 611 res['second'] = obj.second 612 res['microsecond'] = obj.microsecond 613 res['tzinfo'] = jsonclasshintify(obj.tzinfo) 614 return res 615 elif isinstance(obj, datetime.datetime): 616 # this will get decoded as "from jsonobjproxy import {clsname}" 617 # at the remote (client) end. 618 res = {'__jsonclass__': ["jsonobjproxy.DateTime"]} 619 res['year'] = obj.year 620 res['month'] = obj.month 621 res['day'] = obj.day 622 res['hour'] = obj.hour 623 res['minute'] = obj.minute 624 res['second'] = obj.second 625 res['microsecond'] = obj.microsecond 626 res['tzinfo'] = jsonclasshintify(obj.tzinfo) 627 return res 628 elif isinstance(obj, cBusinessDBObject): 629 # this will get decoded as "from jsonobjproxy import {clsname}" 630 # at the remote (client) end. 631 res = {'__jsonclass__': ["jsonobjproxy.%s" % obj.__class__.__name__]} 632 for k in obj.get_fields(): 633 t = jsonclasshintify(obj[k]) 634 res[k] = t 635 print "props", res, dir(obj) 636 for attribute in dir(obj): 637 if not attribute.startswith("get_"): 638 continue 639 k = attribute[4:] 640 if res.has_key(k): 641 continue 642 getter = getattr(obj, attribute, None) 643 if callable(getter): 644 res[k] = jsonclasshintify(getter()) 645 return res 646 return obj
647 648 #============================================================ 649 if __name__ == '__main__': 650 651 if len(sys.argv) < 2: 652 sys.exit() 653 654 if sys.argv[1] != u'test': 655 sys.exit() 656 657 #--------------------------------------------------------
658 - class cTestObj(cBusinessDBObject):
659 _cmd_fetch_payload = None 660 _cmds_store_payload = None 661 _updatable_fields = [] 662 #----------------------------------------------------
663 - def get_something(self):
664 pass
665 #----------------------------------------------------
666 - def set_something(self):
667 pass
668 #-------------------------------------------------------- 669 from Gnumed.pycommon import gmI18N 670 gmI18N.activate_locale() 671 gmI18N.install_domain() 672 673 data = { 674 'pk_field': 'bogus_pk', 675 'idx': {'bogus_pk': 0, 'bogus_field': 1, 'bogus_date': 2}, 676 'data': [-1, 'bogus_data', datetime.datetime.now()] 677 } 678 obj = cTestObj(row=data) 679 #print obj['wrong_field'] 680 #print jsonclasshintify(obj) 681 #obj['wrong_field'] = 1 682 print obj.fields_as_dict() 683 684 #============================================================ 685