1 """Hooks management |
1 from logilab.common.deprecation import class_renamed, class_moved |
2 |
2 from cubicweb.server.hook import Hook |
3 Hooks are called before / after any individual update of entities / relations |
3 SystemHook = class_renamed('SystemHook', Hook) |
4 in the repository. |
4 Hook = class_moved(Hook) |
5 |
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6 Here is the prototype of the different hooks: |
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7 |
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8 * filtered on the entity's type: |
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9 |
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10 before_add_entity (session, entity) |
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11 after_add_entity (session, entity) |
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12 before_update_entity (session, entity) |
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13 after_update_entity (session, entity) |
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14 before_delete_entity (session, eid) |
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15 after_delete_entity (session, eid) |
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16 |
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17 * filtered on the relation's type: |
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18 |
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19 before_add_relation (session, fromeid, rtype, toeid) |
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20 after_add_relation (session, fromeid, rtype, toeid) |
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21 before_delete_relation (session, fromeid, rtype, toeid) |
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22 after_delete_relation (session, fromeid, rtype, toeid) |
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23 |
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24 |
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25 :organization: Logilab |
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26 :copyright: 2001-2009 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2. |
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27 :contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr |
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28 :license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses |
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29 """ |
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30 __docformat__ = "restructuredtext en" |
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31 |
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32 ENTITIES_HOOKS = ('before_add_entity', 'after_add_entity', |
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33 'before_update_entity', 'after_update_entity', |
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34 'before_delete_entity', 'after_delete_entity') |
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35 RELATIONS_HOOKS = ('before_add_relation', 'after_add_relation' , |
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36 'before_delete_relation','after_delete_relation') |
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37 SYSTEM_HOOKS = ('server_backup', 'server_restore', |
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38 'server_startup', 'server_shutdown', |
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39 'session_open', 'session_close') |
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40 |
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41 ALL_HOOKS = frozenset(ENTITIES_HOOKS + RELATIONS_HOOKS + SYSTEM_HOOKS) |
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42 |
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43 class HooksManager(object): |
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44 """handle hooks registration and calls |
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45 """ |
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46 verification_hooks_activated = True |
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47 |
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48 def __init__(self, schema): |
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49 self.set_schema(schema) |
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50 |
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51 def set_schema(self, schema): |
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52 self._hooks = {} |
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53 self.schema = schema |
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54 self._init_hooks(schema) |
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55 |
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56 def register_hooks(self, hooks): |
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57 """register a dictionary of hooks : |
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58 |
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59 {'event': {'entity or relation type': [callbacks list]}} |
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60 """ |
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61 for event, subevents in hooks.items(): |
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62 for subevent, callbacks in subevents.items(): |
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63 for callback in callbacks: |
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64 self.register_hook(callback, event, subevent) |
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65 |
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66 def register_hook(self, function, event, etype=''): |
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67 """register a function to call when <event> occurs |
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68 |
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69 <etype> is an entity/relation type or an empty string. |
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70 |
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71 If etype is the empty string, the function will be called at each event, |
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72 else the function will be called only when event occurs on an entity or |
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73 relation of the given type. |
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74 """ |
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75 assert event in ALL_HOOKS, '%r NOT IN %r' % (event, ALL_HOOKS) |
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76 assert (not event in SYSTEM_HOOKS or not etype), (event, etype) |
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77 etype = etype or '' |
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78 try: |
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79 self._hooks[event][etype].append(function) |
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80 self.debug('registered hook %s on %s (%s)', event, etype or 'any', |
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81 function.func_name) |
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82 |
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83 except KeyError: |
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84 self.error('can\'t register hook %s on %s (%s)', |
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85 event, etype or 'any', function.func_name) |
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86 |
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87 def unregister_hook(self, function_or_cls, event=None, etype=''): |
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88 """unregister a function to call when <event> occurs, or a Hook subclass. |
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89 In the later case, event/type information are extracted from the given |
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90 class. |
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91 """ |
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92 if isinstance(function_or_cls, type) and issubclass(function_or_cls, Hook): |
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93 for event, ertype in function_or_cls.register_to(self.schema): |
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94 for hook in self._hooks[event][ertype]: |
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95 if getattr(hook, 'im_self', None).__class__ is function_or_cls: |
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96 self._hooks[event][ertype].remove(hook) |
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97 self.info('unregister hook %s on %s (%s)', event, etype, |
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98 function_or_cls.__name__) |
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99 break |
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100 else: |
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101 self.warning("can't unregister hook %s on %s (%s), not found", |
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102 event, etype, function_or_cls.__name__) |
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103 else: |
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104 assert event in ALL_HOOKS, event |
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105 etype = etype or '' |
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106 self.info('unregister hook %s on %s (%s)', event, etype, |
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107 function_or_cls.func_name) |
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108 self._hooks[event][etype].remove(function_or_cls) |
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109 |
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110 def call_hooks(self, __event, __type='', *args, **kwargs): |
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111 """call hook matching event and optional type""" |
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112 if __type: |
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113 self.info('calling hooks for event %s (%s)', __event, __type) |
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114 else: |
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115 self.info('calling hooks for event %s', __event) |
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116 # call generic hooks first |
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117 for hook in self._hooks[__event]['']: |
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118 #print '[generic]', hook.__name__ |
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119 hook(*args, **kwargs) |
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120 if __type: |
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121 for hook in self._hooks[__event][__type]: |
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122 #print '[%s]'%__type, hook.__name__ |
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123 hook(*args, **kwargs) |
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124 |
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125 def _init_hooks(self, schema): |
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126 """initialize the hooks map""" |
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127 for hook_event in ENTITIES_HOOKS: |
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128 self._hooks[hook_event] = {'': []} |
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129 for etype in schema.entities(): |
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130 self._hooks[hook_event][etype] = [] |
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131 for hook_event in RELATIONS_HOOKS: |
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132 self._hooks[hook_event] = {'': []} |
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133 for r_type in schema.relations(): |
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134 self._hooks[hook_event][r_type] = [] |
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135 for hook_event in SYSTEM_HOOKS: |
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136 self._hooks[hook_event] = {'': []} |
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137 |
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138 def register_system_hooks(self, config): |
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139 """register system hooks according to the configuration""" |
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140 self.info('register core hooks') |
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141 from cubicweb.server.hooks import _register_metadata_hooks, _register_wf_hooks |
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142 _register_metadata_hooks(self) |
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143 self.info('register workflow hooks') |
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144 _register_wf_hooks(self) |
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145 if config.core_hooks: |
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146 from cubicweb.server.hooks import _register_core_hooks |
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147 _register_core_hooks(self) |
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148 if config.schema_hooks: |
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149 from cubicweb.server.schemahooks import _register_schema_hooks |
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150 self.info('register schema hooks') |
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151 _register_schema_hooks(self) |
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152 if config.usergroup_hooks: |
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153 from cubicweb.server.hooks import _register_usergroup_hooks |
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154 from cubicweb.server.hooks import _register_eproperty_hooks |
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155 self.info('register user/group hooks') |
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156 _register_usergroup_hooks(self) |
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157 _register_eproperty_hooks(self) |
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158 if config.security_hooks: |
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159 from cubicweb.server.securityhooks import register_security_hooks |
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160 self.info('register security hooks') |
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161 register_security_hooks(self) |
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162 if not self.verification_hooks_activated: |
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163 self.deactivate_verification_hooks() |
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164 |
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165 def deactivate_verification_hooks(self): |
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166 from cubicweb.server.hooks import (cardinalitycheck_after_add_entity, |
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167 cardinalitycheck_before_del_relation, |
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168 cstrcheck_after_add_relation, |
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169 uniquecstrcheck_before_modification) |
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170 self.warning('deactivating verification hooks') |
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171 self.verification_hooks_activated = False |
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172 self.unregister_hook(cardinalitycheck_after_add_entity, 'after_add_entity', '') |
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173 self.unregister_hook(cardinalitycheck_before_del_relation, 'before_delete_relation', '') |
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174 self.unregister_hook(cstrcheck_after_add_relation, 'after_add_relation', '') |
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175 self.unregister_hook(uniquecstrcheck_before_modification, 'before_add_entity', '') |
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176 self.unregister_hook(uniquecstrcheck_before_modification, 'before_update_entity', '') |
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177 # self.unregister_hook(tidy_html_fields('before_add_entity'), 'before_add_entity', '') |
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178 # self.unregister_hook(tidy_html_fields('before_update_entity'), 'before_update_entity', '') |
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179 |
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180 def reactivate_verification_hooks(self): |
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181 from cubicweb.server.hooks import (cardinalitycheck_after_add_entity, |
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182 cardinalitycheck_before_del_relation, |
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183 cstrcheck_after_add_relation, |
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184 uniquecstrcheck_before_modification) |
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185 self.warning('reactivating verification hooks') |
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186 self.verification_hooks_activated = True |
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187 self.register_hook(cardinalitycheck_after_add_entity, 'after_add_entity', '') |
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188 self.register_hook(cardinalitycheck_before_del_relation, 'before_delete_relation', '') |
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189 self.register_hook(cstrcheck_after_add_relation, 'after_add_relation', '') |
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190 self.register_hook(uniquecstrcheck_before_modification, 'before_add_entity', '') |
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191 self.register_hook(uniquecstrcheck_before_modification, 'before_update_entity', '') |
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192 # self.register_hook(tidy_html_fields('before_add_entity'), 'before_add_entity', '') |
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193 # self.register_hook(tidy_html_fields('before_update_entity'), 'before_update_entity', '') |
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194 |
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195 from cubicweb.selectors import yes |
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196 from cubicweb.appobject import AppObject |
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197 |
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198 class autoid(type): |
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199 """metaclass to create an unique 'id' attribute on the class using it""" |
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200 # XXX is this metaclass really necessary ? |
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201 def __new__(mcs, name, bases, classdict): |
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202 cls = super(autoid, mcs).__new__(mcs, name, bases, classdict) |
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203 cls.id = str(id(cls)) |
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204 return cls |
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205 |
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206 class Hook(AppObject): |
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207 __metaclass__ = autoid |
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208 __registry__ = 'hooks' |
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209 __select__ = yes() |
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210 # set this in derivated classes |
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211 events = None |
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212 accepts = None |
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213 enabled = True |
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214 |
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215 def __init__(self, event=None): |
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216 super(Hook, self).__init__(None) |
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217 self.event = event |
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218 |
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219 @classmethod |
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220 def __registered__(cls, vreg): |
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221 super(Hook, cls).__registered__(vreg) |
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222 return cls() |
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223 |
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224 @classmethod |
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225 def register_to(cls, schema): |
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226 if not cls.enabled: |
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227 cls.warning('%s hook has been disabled', cls) |
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228 return |
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229 done = set() |
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230 assert isinstance(cls.events, (tuple, list)), \ |
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231 '%s: events is expected to be a tuple, not %s' % ( |
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232 cls, type(cls.events)) |
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233 for event in cls.events: |
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234 if event in SYSTEM_HOOKS: |
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235 assert not cls.accepts or cls.accepts == ('Any',), \ |
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236 '%s doesnt make sense on %s' % (cls.accepts, event) |
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237 cls.accepts = ('Any',) |
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238 for ertype in cls.accepts: |
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239 if (event, ertype) in done: |
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240 continue |
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241 yield event, ertype |
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242 done.add((event, ertype)) |
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243 try: |
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244 eschema = schema.eschema(ertype) |
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245 except KeyError: |
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246 # relation schema |
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247 pass |
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248 else: |
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249 for eetype in eschema.specialized_by(): |
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250 if (event, eetype) in done: |
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251 continue |
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252 yield event, str(eetype) |
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253 done.add((event, eetype)) |
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254 |
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255 |
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256 def make_callback(self, event): |
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257 if len(self.events) == 1: |
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258 return self.call |
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259 return self.__class__(event=event).call |
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260 |
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261 def call(self): |
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262 raise NotImplementedError |
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263 |
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264 class SystemHook(Hook): |
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265 accepts = () |
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266 |
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267 from logging import getLogger |
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268 from cubicweb import set_log_methods |
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269 set_log_methods(HooksManager, getLogger('cubicweb.hooksmanager')) |
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270 set_log_methods(Hook, getLogger('cubicweb.hooks')) |
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