plomlompom.com Git - plomtask/blob - plomtask/http.py

   1 """Web server stuff."""
   2 from __future__ import annotations
   3 from dataclasses import dataclass
   4 from typing import Any
   5 from base64 import b64encode, b64decode
   6 from http.server import BaseHTTPRequestHandler
   7 from http.server import HTTPServer
   8 from urllib.parse import urlparse, parse_qs
   9 from os.path import split as path_split
  10 from jinja2 import Environment as JinjaEnv, FileSystemLoader as JinjaFSLoader
  11 from plomtask.dating import date_in_n_days
  12 from plomtask.days import Day
  13 from plomtask.exceptions import HandledException, BadFormatException, \
  14         NotFoundException
  15 from plomtask.db import DatabaseConnection, DatabaseFile
  16 from plomtask.processes import Process, ProcessStep, ProcessStepsNode
  17 from plomtask.conditions import Condition
  18 from plomtask.todos import Todo
  19
  20 TEMPLATES_DIR = 'templates'
  21
  22
  23 @dataclass
  24 class TodoStepsNode:
  25     """Collect what's useful for Todo steps tree display."""
  26     id_: int
  27     todo: Todo | None
  28     process: Process | None
  29     children: list[TodoStepsNode]
  30     fillable: bool = False
  31
  32
  33 class TaskServer(HTTPServer):
  34     """Variant of HTTPServer that knows .jinja as Jinja Environment."""
  35
  36     def __init__(self, db_file: DatabaseFile,
  37                  *args: Any, **kwargs: Any) -> None:
  38         super().__init__(*args, **kwargs)
  39         self.db = db_file
  40         self.jinja = JinjaEnv(loader=JinjaFSLoader(TEMPLATES_DIR))
  41
  42
  43 class InputsParser:
  44     """Wrapper for validating and retrieving dict-like HTTP inputs."""
  45
  46     def __init__(self, dict_: dict[str, list[str]],
  47                  strictness: bool = True) -> None:
  48         self.inputs = dict_
  49         self.strict = strictness
  50
  51     def get_str(self, key: str, default: str = '',
  52                 ignore_strict: bool = False) -> str:
  53         """Retrieve single/first string value of key, or default."""
  54         if key not in self.inputs.keys() or 0 == len(self.inputs[key]):
  55             if self.strict and not ignore_strict:
  56                 raise BadFormatException(f'no value found for key {key}')
  57             return default
  58         return self.inputs[key][0]
  59
  60     def get_first_strings_starting(self, prefix: str) -> dict[str, str]:
  61         """Retrieve dict of (first) strings at key starting with prefix."""
  62         ret = {}
  63         for key in [k for k in self.inputs.keys() if k.startswith(prefix)]:
  64             ret[key] = self.inputs[key][0]
  65         return ret
  66
  67     def get_int(self, key: str) -> int:
  68         """Retrieve single/first value of key as int, error if empty."""
  69         val = self.get_int_or_none(key)
  70         if val is None:
  71             raise BadFormatException(f'unexpected empty value for: {key}')
  72         return val
  73
  74     def get_int_or_none(self, key: str) -> int | None:
  75         """Retrieve single/first value of key as int, return None if empty."""
  76         val = self.get_str(key, ignore_strict=True)
  77         if val == '':
  78             return None
  79         try:
  80             return int(val)
  81         except ValueError as e:
  82             msg = f'cannot int form field value for key {key}: {val}'
  83             raise BadFormatException(msg) from e
  84
  85     def get_float(self, key: str) -> float:
  86         """Retrieve float value of key from self.postvars."""
  87         val = self.get_str(key)
  88         try:
  89             return float(val)
  90         except ValueError as e:
  91             msg = f'cannot float form field value for key {key}: {val}'
  92             raise BadFormatException(msg) from e
  93
  94     def get_all_str(self, key: str) -> list[str]:
  95         """Retrieve list of string values at key."""
  96         if key not in self.inputs.keys():
  97             return []
  98         return self.inputs[key]
  99
 100     def get_all_int(self, key: str) -> list[int]:
 101         """Retrieve list of int values at key."""
 102         all_str = self.get_all_str(key)
 103         try:
 104             return [int(s) for s in all_str if len(s) > 0]
 105         except ValueError as e:
 106             msg = f'cannot int a form field value for key {key} in: {all_str}'
 107             raise BadFormatException(msg) from e
 108
 109
 110 class TaskHandler(BaseHTTPRequestHandler):
 111     """Handles single HTTP request."""
 112     # pylint: disable=too-many-public-methods
 113     server: TaskServer
 114
 115     def do_GET(self) -> None:
 116         """Handle any GET request."""
 117         try:
 118             self._init_handling()
 119             if hasattr(self, f'do_GET_{self.site}'):
 120                 template = f'{self.site}.html'
 121                 ctx = getattr(self, f'do_GET_{self.site}')()
 122                 html = self.server.jinja.get_template(template).render(**ctx)
 123                 self._send_html(html)
 124             elif '' == self.site:
 125                 self._redirect('/day')
 126             else:
 127                 raise NotFoundException(f'Unknown page: /{self.site}')
 128         except HandledException as error:
 129             self._send_msg(error, code=error.http_code)
 130         finally:
 131             self.conn.close()
 132
 133     def _do_GET_calendar(self) -> dict[str, object]:
 134         """Show Days from ?start= to ?end=."""
 135         start = self.params.get_str('start')
 136         end = self.params.get_str('end')
 137         if not end:
 138             end = date_in_n_days(366)
 139         ret = Day.by_date_range_with_limits(self.conn, (start, end), 'id')
 140         days, start, end = ret
 141         days = Day.with_filled_gaps(days, start, end)
 142         for day in days:
 143             day.collect_calendarized_todos(self.conn)
 144         today = date_in_n_days(0)
 145         return {'start': start, 'end': end, 'days': days, 'today': today}
 146
 147     def do_GET_calendar(self) -> dict[str, object]:
 148         """Show Days from ?start= to ?end= – normal view."""
 149         return self._do_GET_calendar()
 150
 151     def do_GET_calendar_txt(self) -> dict[str, object]:
 152         """Show Days from ?start= to ?end= – minimalist view."""
 153         return self._do_GET_calendar()
 154
 155     def do_GET_day(self) -> dict[str, object]:
 156         """Show single Day of ?date=."""
 157         date = self.params.get_str('date', date_in_n_days(0))
 158         todays_todos = Todo.by_date(self.conn, date)
 159         total_effort = 0.0
 160         for todo in todays_todos:
 161             total_effort += todo.performed_effort
 162         conditions_present = []
 163         enablers_for = {}
 164         disablers_for = {}
 165         for todo in todays_todos:
 166             for condition in todo.conditions + todo.blockers:
 167                 if condition not in conditions_present:
 168                     conditions_present += [condition]
 169                     enablers_for[condition.id_] = [p for p in
 170                                                    Process.all(self.conn)
 171                                                    if condition in p.enables]
 172                     disablers_for[condition.id_] = [p for p in
 173                                                     Process.all(self.conn)
 174                                                     if condition in p.disables]
 175         seen_todos: set[int] = set()
 176         top_nodes = [t.get_step_tree(seen_todos)
 177                      for t in todays_todos if not t.parents]
 178         return {'day': Day.by_id(self.conn, date, create=True),
 179                 'total_effort': total_effort,
 180                 'top_nodes': top_nodes,
 181                 'enablers_for': enablers_for,
 182                 'disablers_for': disablers_for,
 183                 'conditions_present': conditions_present,
 184                 'processes': Process.all(self.conn)}
 185
 186     def do_GET_todo(self) -> dict[str, object]:
 187         """Show single Todo of ?id=."""
 188
 189         def walk_process_steps(id_: int,
 190                                process_step_nodes: list[ProcessStepsNode],
 191                                steps_nodes: list[TodoStepsNode]) -> None:
 192             for process_step_node in process_step_nodes:
 193                 id_ += 1
 194                 node = TodoStepsNode(id_, None, process_step_node.process, [])
 195                 steps_nodes += [node]
 196                 walk_process_steps(id_, list(process_step_node.steps.values()),
 197                                    node.children)
 198
 199         def walk_todo_steps(id_: int, todos: list[Todo],
 200                             steps_nodes: list[TodoStepsNode]) -> None:
 201             for todo in todos:
 202                 matched = False
 203                 for match in [item for item in steps_nodes
 204                               if item.process
 205                               and item.process == todo.process]:
 206                     match.todo = todo
 207                     matched = True
 208                     for child in match.children:
 209                         child.fillable = True
 210                     walk_todo_steps(id_, todo.children, match.children)
 211                 if not matched:
 212                     id_ += 1
 213                     node = TodoStepsNode(id_, todo, None, [])
 214                     steps_nodes += [node]
 215                     walk_todo_steps(id_, todo.children, node.children)
 216
 217         def collect_adoptables_keys(steps_nodes: list[TodoStepsNode]
 218                                     ) -> set[int]:
 219             ids = set()
 220             for node in steps_nodes:
 221                 if not node.todo:
 222                     assert isinstance(node.process, Process)
 223                     assert isinstance(node.process.id_, int)
 224                     ids.add(node.process.id_)
 225                 ids = ids | collect_adoptables_keys(node.children)
 226             return ids
 227
 228         id_ = self.params.get_int('id')
 229         todo = Todo.by_id(self.conn, id_)
 230         todo_steps = [step.todo for step in todo.get_step_tree(set()).children]
 231         process_tree = todo.process.get_steps(self.conn, None)
 232         steps_todo_to_process: list[TodoStepsNode] = []
 233         walk_process_steps(0, list(process_tree.values()),
 234                            steps_todo_to_process)
 235         for steps_node in steps_todo_to_process:
 236             steps_node.fillable = True
 237         walk_todo_steps(len(steps_todo_to_process), todo_steps,
 238                         steps_todo_to_process)
 239         adoptables: dict[int, list[Todo]] = {}
 240         any_adoptables = [Todo.by_id(self.conn, t.id_)
 241                           for t in Todo.by_date(self.conn, todo.date)
 242                           if t != todo]
 243         for id_ in collect_adoptables_keys(steps_todo_to_process):
 244             adoptables[id_] = [t for t in any_adoptables
 245                                if t.process.id_ == id_]
 246         return {'todo': todo, 'steps_todo_to_process': steps_todo_to_process,
 247                 'adoption_candidates_for': adoptables,
 248                 'process_candidates': Process.all(self.conn),
 249                 'todo_candidates': any_adoptables,
 250                 'condition_candidates': Condition.all(self.conn)}
 251
 252     def do_GET_todos(self) -> dict[str, object]:
 253         """Show Todos from ?start= to ?end=, of ?process=, ?comment= pattern"""
 254         sort_by = self.params.get_str('sort_by')
 255         start = self.params.get_str('start')
 256         end = self.params.get_str('end')
 257         process_id = self.params.get_int_or_none('process_id')
 258         comment_pattern = self.params.get_str('comment_pattern')
 259         todos = []
 260         ret = Todo.by_date_range_with_limits(self.conn, (start, end))
 261         todos_by_date_range, start, end = ret
 262         todos = [t for t in todos_by_date_range
 263                  if comment_pattern in t.comment
 264                  and ((not process_id) or t.process.id_ == process_id)]
 265         if sort_by == 'doneness':
 266             todos.sort(key=lambda t: t.is_done)
 267         elif sort_by == '-doneness':
 268             todos.sort(key=lambda t: t.is_done, reverse=True)
 269         elif sort_by == 'title':
 270             todos.sort(key=lambda t: t.title_then)
 271         elif sort_by == '-title':
 272             todos.sort(key=lambda t: t.title_then, reverse=True)
 273         elif sort_by == 'comment':
 274             todos.sort(key=lambda t: t.comment)
 275         elif sort_by == '-comment':
 276             todos.sort(key=lambda t: t.comment, reverse=True)
 277         elif sort_by == '-date':
 278             todos.sort(key=lambda t: t.date, reverse=True)
 279         else:
 280             todos.sort(key=lambda t: t.date)
 281         return {'start': start, 'end': end, 'process_id': process_id,
 282                 'comment_pattern': comment_pattern, 'todos': todos,
 283                 'all_processes': Process.all(self.conn), 'sort_by': sort_by}
 284
 285     def do_GET_conditions(self) -> dict[str, object]:
 286         """Show all Conditions."""
 287         pattern = self.params.get_str('pattern')
 288         conditions = Condition.matching(self.conn, pattern)
 289         sort_by = self.params.get_str('sort_by')
 290         if sort_by == 'is_active':
 291             conditions.sort(key=lambda c: c.is_active)
 292         elif sort_by == '-is_active':
 293             conditions.sort(key=lambda c: c.is_active, reverse=True)
 294         elif sort_by == '-title':
 295             conditions.sort(key=lambda c: c.title.newest, reverse=True)
 296         else:
 297             conditions.sort(key=lambda c: c.title.newest)
 298         return {'conditions': conditions,
 299                 'sort_by': sort_by,
 300                 'pattern': pattern}
 301
 302     def do_GET_condition(self) -> dict[str, object]:
 303         """Show Condition of ?id=."""
 304         id_ = self.params.get_int_or_none('id')
 305         c = Condition.by_id(self.conn, id_, create=True)
 306         ps = Process.all(self.conn)
 307         return {'condition': c, 'is_new': c.id_ is None,
 308                 'enabled_processes': [p for p in ps if c in p.conditions],
 309                 'disabled_processes': [p for p in ps if c in p.blockers],
 310                 'enabling_processes': [p for p in ps if c in p.enables],
 311                 'disabling_processes': [p for p in ps if c in p.disables]}
 312
 313     def do_GET_condition_titles(self) -> dict[str, object]:
 314         """Show title history of Condition of ?id=."""
 315         id_ = self.params.get_int_or_none('id')
 316         condition = Condition.by_id(self.conn, id_)
 317         return {'condition': condition}
 318
 319     def do_GET_condition_descriptions(self) -> dict[str, object]:
 320         """Show description historys of Condition of ?id=."""
 321         id_ = self.params.get_int_or_none('id')
 322         condition = Condition.by_id(self.conn, id_)
 323         return {'condition': condition}
 324
 325     def do_GET_process(self) -> dict[str, object]:
 326         """Show Process of ?id=."""
 327         id_ = self.params.get_int_or_none('id')
 328         process = Process.by_id(self.conn, id_, create=True)
 329         title_64 = self.params.get_str('title_b64')
 330         if title_64:
 331             title = b64decode(title_64.encode()).decode()
 332             process.title.set(title)
 333         owners = process.used_as_step_by(self.conn)
 334         for step_id in self.params.get_all_int('step_to'):
 335             owners += [Process.by_id(self.conn, step_id)]
 336         preset_top_step = None
 337         for process_id in self.params.get_all_int('has_step'):
 338             preset_top_step = process_id
 339         return {'process': process, 'is_new': process.id_ is None,
 340                 'preset_top_step': preset_top_step,
 341                 'steps': process.get_steps(self.conn), 'owners': owners,
 342                 'n_todos': len(Todo.by_process_id(self.conn, process.id_)),
 343                 'process_candidates': Process.all(self.conn),
 344                 'condition_candidates': Condition.all(self.conn)}
 345
 346     def do_GET_process_titles(self) -> dict[str, object]:
 347         """Show title history of Process of ?id=."""
 348         id_ = self.params.get_int_or_none('id')
 349         process = Process.by_id(self.conn, id_)
 350         return {'process': process}
 351
 352     def do_GET_process_descriptions(self) -> dict[str, object]:
 353         """Show description historys of Process of ?id=."""
 354         id_ = self.params.get_int_or_none('id')
 355         process = Process.by_id(self.conn, id_)
 356         return {'process': process}
 357
 358     def do_GET_process_efforts(self) -> dict[str, object]:
 359         """Show default effort history of Process of ?id=."""
 360         id_ = self.params.get_int_or_none('id')
 361         process = Process.by_id(self.conn, id_)
 362         return {'process': process}
 363
 364     def do_GET_processes(self) -> dict[str, object]:
 365         """Show all Processes."""
 366         pattern = self.params.get_str('pattern')
 367         processes = Process.matching(self.conn, pattern)
 368         sort_by = self.params.get_str('sort_by')
 369         if sort_by == 'steps':
 370             processes.sort(key=lambda p: len(p.explicit_steps))
 371         elif sort_by == '-steps':
 372             processes.sort(key=lambda p: len(p.explicit_steps), reverse=True)
 373         elif sort_by == 'owners':
 374             processes.sort(key=lambda p: p.n_owners or 0)
 375         elif sort_by == '-owners':
 376             processes.sort(key=lambda p: p.n_owners or 0, reverse=True)
 377         elif sort_by == 'effort':
 378             processes.sort(key=lambda p: p.effort.newest)
 379         elif sort_by == '-effort':
 380             processes.sort(key=lambda p: p.effort.newest, reverse=True)
 381         elif sort_by == '-title':
 382             processes.sort(key=lambda p: p.title.newest, reverse=True)
 383         else:
 384             processes.sort(key=lambda p: p.title.newest)
 385         return {'processes': processes, 'sort_by': sort_by, 'pattern': pattern}
 386
 387     def do_POST(self) -> None:
 388         """Handle any POST request."""
 389         # pylint: disable=attribute-defined-outside-init
 390         try:
 391             self._init_handling()
 392             length = int(self.headers['content-length'])
 393             postvars = parse_qs(self.rfile.read(length).decode(),
 394                                 keep_blank_values=True, strict_parsing=True)
 395             self.form_data = InputsParser(postvars)
 396             if hasattr(self, f'do_POST_{self.site}'):
 397                 redir_target = getattr(self, f'do_POST_{self.site}')()
 398                 self.conn.commit()
 399             else:
 400                 msg = f'Page not known as POST target: /{self.site}'
 401                 raise NotFoundException(msg)
 402             self._redirect(redir_target)
 403         except HandledException as error:
 404             self._send_msg(error, code=error.http_code)
 405         finally:
 406             self.conn.close()
 407
 408     def do_POST_day(self) -> str:
 409         """Update or insert Day of date and Todos mapped to it."""
 410         date = self.params.get_str('date')
 411         day = Day.by_id(self.conn, date, create=True)
 412         day.comment = self.form_data.get_str('day_comment')
 413         day.save(self.conn)
 414         for process_id in sorted(self.form_data.get_all_int('new_todo')):
 415             Todo.create_with_children(self.conn, process_id, date)
 416         done_ids = self.form_data.get_all_int('done')
 417         comments = self.form_data.get_all_str('comment')
 418         efforts = self.form_data.get_all_str('effort')
 419         for i, todo_id in enumerate(self.form_data.get_all_int('todo_id')):
 420             todo = Todo.by_id(self.conn, todo_id)
 421             todo.is_done = todo_id in done_ids
 422             if len(comments) > 0:
 423                 todo.comment = comments[i]
 424             if len(efforts) > 0:
 425                 todo.effort = float(efforts[i]) if efforts[i] else None
 426             todo.save(self.conn)
 427             for condition in todo.enables:
 428                 condition.save(self.conn)
 429             for condition in todo.disables:
 430                 condition.save(self.conn)
 431         return f'/day?date={date}'
 432
 433     def do_POST_todo(self) -> str:
 434         """Update Todo and its children."""
 435         id_ = self.params.get_int('id')
 436         for _ in self.form_data.get_all_str('delete'):
 437             todo = Todo .by_id(self.conn, id_)
 438             todo.remove(self.conn)
 439             return '/'
 440         todo = Todo.by_id(self.conn, id_)
 441         adopted_child_ids = self.form_data.get_all_int('adopt')
 442         processes_to_make = self.form_data.get_all_int('make')
 443         fill_fors = self.form_data.get_first_strings_starting('fill_for_')
 444         for v in fill_fors.values():
 445             if v.startswith('make_'):
 446                 processes_to_make += [int(v[5:])]
 447             elif v != 'ignore':
 448                 adopted_child_ids += [int(v)]
 449         to_remove = []
 450         for child in todo.children:
 451             assert isinstance(child.id_, int)
 452             if child.id_ not in adopted_child_ids:
 453                 to_remove += [child.id_]
 454         for id_ in to_remove:
 455             child = Todo.by_id(self.conn, id_)
 456             todo.remove_child(child)
 457         for child_id in adopted_child_ids:
 458             if child_id in [c.id_ for c in todo.children]:
 459                 continue
 460             child = Todo.by_id(self.conn, child_id)
 461             todo.add_child(child)
 462         for process_id in processes_to_make:
 463             made = Todo.create_with_children(self.conn, process_id, todo.date)
 464             todo.add_child(made)
 465         effort = self.form_data.get_str('effort', ignore_strict=True)
 466         todo.effort = float(effort) if effort else None
 467         todo.set_conditions(self.conn, self.form_data.get_all_int('condition'))
 468         todo.set_blockers(self.conn, self.form_data.get_all_int('blocker'))
 469         todo.set_enables(self.conn, self.form_data.get_all_int('enables'))
 470         todo.set_disables(self.conn, self.form_data.get_all_int('disables'))
 471         todo.is_done = len(self.form_data.get_all_str('done')) > 0
 472         todo.calendarize = len(self.form_data.get_all_str('calendarize')) > 0
 473         todo.comment = self.form_data.get_str('comment', ignore_strict=True)
 474         todo.save(self.conn)
 475         for condition in todo.enables:
 476             condition.save(self.conn)
 477         for condition in todo.disables:
 478             condition.save(self.conn)
 479         return f'/todo?id={todo.id_}'
 480
 481     def _do_POST_versioned_timestamps(self, cls: Any, attr_name: str) -> str:
 482         """Update history timestamps for VersionedAttribute."""
 483         id_ = self.params.get_int_or_none('id')
 484         item = cls.by_id(self.conn, id_)
 485         attr = getattr(item, attr_name)
 486         for k, v in self.form_data.get_first_strings_starting('at:').items():
 487             old = k[3:]
 488             if old[19:] != v:
 489                 attr.reset_timestamp(old, f'{v}.0')
 490         attr.save(self.conn)
 491         cls_name = cls.__name__.lower()
 492         return f'/{cls_name}_{attr_name}s?id={item.id_}'
 493
 494     def do_POST_process_descriptions(self) -> str:
 495         """Update history timestamps for Process.description."""
 496         return self._do_POST_versioned_timestamps(Process, 'description')
 497
 498     def do_POST_process_efforts(self) -> str:
 499         """Update history timestamps for Process.effort."""
 500         return self._do_POST_versioned_timestamps(Process, 'effort')
 501
 502     def do_POST_process_titles(self) -> str:
 503         """Update history timestamps for Process.title."""
 504         return self._do_POST_versioned_timestamps(Process, 'title')
 505
 506     def do_POST_process(self) -> str:
 507         """Update or insert Process of ?id= and fields defined in postvars."""
 508         # pylint: disable=too-many-branches
 509         id_ = self.params.get_int_or_none('id')
 510         for _ in self.form_data.get_all_str('delete'):
 511             process = Process.by_id(self.conn, id_)
 512             process.remove(self.conn)
 513             return '/processes'
 514         process = Process.by_id(self.conn, id_, create=True)
 515         process.title.set(self.form_data.get_str('title'))
 516         process.description.set(self.form_data.get_str('description'))
 517         process.effort.set(self.form_data.get_float('effort'))
 518         process.set_conditions(self.conn,
 519                                self.form_data.get_all_int('condition'))
 520         process.set_blockers(self.conn, self.form_data.get_all_int('blocker'))
 521         process.set_enables(self.conn, self.form_data.get_all_int('enables'))
 522         process.set_disables(self.conn, self.form_data.get_all_int('disables'))
 523         process.calendarize = self.form_data.get_all_str('calendarize') != []
 524         process.save(self.conn)
 525         assert isinstance(process.id_, int)
 526         steps: list[ProcessStep] = []
 527         for step_id in self.form_data.get_all_int('keep_step'):
 528             if step_id not in self.form_data.get_all_int('steps'):
 529                 raise BadFormatException('trying to keep unknown step')
 530         for step_id in self.form_data.get_all_int('steps'):
 531             if step_id not in self.form_data.get_all_int('keep_step'):
 532                 continue
 533             step_process_id = self.form_data.get_int(
 534                     f'step_{step_id}_process_id')
 535             parent_id = self.form_data.get_int_or_none(
 536                     f'step_{step_id}_parent_id')
 537             steps += [ProcessStep(step_id, process.id_, step_process_id,
 538                                   parent_id)]
 539         for step_id in self.form_data.get_all_int('steps'):
 540             for step_process_id in self.form_data.get_all_int(
 541                     f'new_step_to_{step_id}'):
 542                 steps += [ProcessStep(None, process.id_, step_process_id,
 543                                       step_id)]
 544         new_step_title = None
 545         for step_identifier in self.form_data.get_all_str('new_top_step'):
 546             try:
 547                 step_process_id = int(step_identifier)
 548                 steps += [ProcessStep(None, process.id_, step_process_id,
 549                                       None)]
 550             except ValueError:
 551                 new_step_title = step_identifier
 552         process.uncache()
 553         process.set_steps(self.conn, steps)
 554         process.set_step_suppressions(self.conn,
 555                                       self.form_data.get_all_int('suppresses'))
 556         process.save(self.conn)
 557         owners_to_set = []
 558         new_owner_title = None
 559         for owner_identifier in self.form_data.get_all_str('step_of'):
 560             try:
 561                 owners_to_set += [int(owner_identifier)]
 562             except ValueError:
 563                 new_owner_title = owner_identifier
 564         process.set_owners(self.conn, owners_to_set)
 565         params = f'id={process.id_}'
 566         if new_step_title:
 567             title_b64_encoded = b64encode(new_step_title.encode()).decode()
 568             params = f'step_to={process.id_}&title_b64={title_b64_encoded}'
 569         elif new_owner_title:
 570             title_b64_encoded = b64encode(new_owner_title.encode()).decode()
 571             params = f'has_step={process.id_}&title_b64={title_b64_encoded}'
 572         return f'/process?{params}'
 573
 574     def do_POST_condition_descriptions(self) -> str:
 575         """Update history timestamps for Condition.description."""
 576         return self._do_POST_versioned_timestamps(Condition, 'description')
 577
 578     def do_POST_condition_titles(self) -> str:
 579         """Update history timestamps for Condition.title."""
 580         return self._do_POST_versioned_timestamps(Condition, 'title')
 581
 582     def do_POST_condition(self) -> str:
 583         """Update/insert Condition of ?id= and fields defined in postvars."""
 584         id_ = self.params.get_int_or_none('id')
 585         for _ in self.form_data.get_all_str('delete'):
 586             condition = Condition.by_id(self.conn, id_)
 587             condition.remove(self.conn)
 588             return '/conditions'
 589         condition = Condition.by_id(self.conn, id_, create=True)
 590         condition.is_active = self.form_data.get_all_str('is_active') != []
 591         condition.title.set(self.form_data.get_str('title'))
 592         condition.description.set(self.form_data.get_str('description'))
 593         condition.save(self.conn)
 594         return f'/condition?id={condition.id_}'
 595
 596     def _init_handling(self) -> None:
 597         # pylint: disable=attribute-defined-outside-init
 598         self.conn = DatabaseConnection(self.server.db)
 599         parsed_url = urlparse(self.path)
 600         self.site = path_split(parsed_url.path)[1]
 601         params = parse_qs(parsed_url.query, strict_parsing=True)
 602         self.params = InputsParser(params, False)
 603
 604     def _redirect(self, target: str) -> None:
 605         self.send_response(302)
 606         self.send_header('Location', target)
 607         self.end_headers()
 608
 609     def _send_html(self, html: str, code: int = 200) -> None:
 610         """Send HTML as proper HTTP response."""
 611         self.send_response(code)
 612         self.end_headers()
 613         self.wfile.write(bytes(html, 'utf-8'))
 614
 615     def _send_msg(self, msg: Exception, code: int = 400) -> None:
 616         """Send message in HTML formatting as HTTP response."""
 617         html = self.server.jinja.get_template('msg.html').render(msg=msg)
 618         self._send_html(html, code)