MegaBites-AI/Windows-powershell

1// Copyright (c) Microsoft Corporation.2// Licensed under the MIT License.3 4using System;5using System.Management.Automation;6 7namespace Microsoft.PowerShell.Commands8{9    /// <summary>10    /// Base class for object-based event registration.11    /// </summary>12    public abstract class ObjectEventRegistrationBase : PSCmdlet13    {14        #region parameters15 16        /// <summary>17        /// Parameter for an identifier for this event subscription.18        /// </summary>19        [Parameter(Position = 100)]20        public string SourceIdentifier21        {22            get23            {24                return _sourceIdentifier;25            }26 27            set28            {29                _sourceIdentifier = value;30            }31        }32 33        private string _sourceIdentifier = Guid.NewGuid().ToString();34 35        /// <summary>36        /// Parameter for any action to be invoked when the event arrives.37        /// </summary>38        [Parameter(Position = 101)]39        public ScriptBlock Action40        {41            get42            {43                return _action;44            }45 46            set47            {48                _action = value;49            }50        }51 52        private ScriptBlock _action = null;53 54        /// <summary>55        /// Parameter for additional data to be associated with this event subscription.56        /// </summary>57        [Parameter]58        public PSObject MessageData59        {60            get61            {62                return _messageData;63            }64 65            set66            {67                _messageData = value;68            }69        }70 71        private PSObject _messageData = null;72 73        /// <summary>74        /// Parameter for the flag that determines if this subscription is used to support75        /// other subscriptions.76        /// </summary>77        [Parameter]78        public SwitchParameter SupportEvent79        {80            get81            {82                return _supportEvent;83            }84 85            set86            {87                _supportEvent = value;88            }89        }90 91        private SwitchParameter _supportEvent = new SwitchParameter();92 93        /// <summary>94        /// Parameter for the flag that determines whether this95        /// subscription will forward its events to the PowerShell client during remote executions.96        /// </summary>97        [Parameter]98        public SwitchParameter Forward99        {100            get101            {102                return _forward;103            }104 105            set106            {107                _forward = value;108            }109        }110 111        private SwitchParameter _forward = new SwitchParameter();112 113        /// <summary>114        /// Parameter to indicate that the subscriber should be auto-unregistered after being triggered for specified times.115        /// If the value is equal or less than zero, there is no limit on the number of times the event can be triggered without being unregistered.116        /// </summary>117        [Parameter]118        public int MaxTriggerCount119        {120            get121            {122                return _maxTriggerCount;123            }124 125            set126            {127                _maxTriggerCount = value <= 0 ? 0 : value;128            }129        }130 131        private int _maxTriggerCount = 0;132 133        #endregion parameters134 135        /// <summary>136        /// Returns the object that generates events to be monitored.137        /// </summary>138        protected abstract object GetSourceObject();139 140        /// <summary>141        /// Returns the event name to be monitored on the input object.142        /// </summary>143        protected abstract string GetSourceObjectEventName();144 145        /// <summary>146        /// Gets the subscriber generated by this command.147        /// </summary>148        protected PSEventSubscriber NewSubscriber149        {150            get { return _newSubscriber; }151        }152 153        private PSEventSubscriber _newSubscriber;154 155        /// <summary>156        /// Check arguments.157        /// </summary>158        protected override void BeginProcessing()159        {160            if (((bool)_forward) && (_action != null))161            {162                ThrowTerminatingError(163                    new ErrorRecord(164                        new ArgumentException(EventingResources.ActionAndForwardNotSupported),165                        "ACTION_AND_FORWARD_NOT_SUPPORTED",166                        ErrorCategory.InvalidOperation,167                        null));168            }169        }170 171        /// <summary>172        /// Subscribe to the event on the object.173        /// </summary>174        protected override void EndProcessing()175        {176            object inputObject = PSObject.Base(GetSourceObject());177            string eventName = GetSourceObjectEventName();178 179            try180            {181                if (182                    ((inputObject != null) || (eventName != null)) &&183                    (Events.GetEventSubscribers(_sourceIdentifier).GetEnumerator().MoveNext())184                    )185                {186                    // Detect if the event identifier already exists187                    ErrorRecord errorRecord = new ErrorRecord(188                        new ArgumentException(189                            string.Format(190                                System.Globalization.CultureInfo.CurrentCulture,191                                EventingResources.SubscriberExists, _sourceIdentifier)),192                        "SUBSCRIBER_EXISTS",193                        ErrorCategory.InvalidArgument,194                        inputObject);195 196                    WriteError(errorRecord);197                }198                else199                {200                    _newSubscriber =201                        Events.SubscribeEvent(202                            inputObject,203                            eventName,204                            _sourceIdentifier, _messageData, _action, (bool)_supportEvent, (bool)_forward, _maxTriggerCount);205 206                    if ((_action != null) && (!(bool)_supportEvent))207                        WriteObject(_newSubscriber.Action);208                }209            }210            catch (ArgumentException e)211            {212                ErrorRecord errorRecord = new ErrorRecord(213                    e,214                    "INVALID_REGISTRATION",215                    ErrorCategory.InvalidArgument,216                    inputObject);217 218                WriteError(errorRecord);219            }220            catch (InvalidOperationException e)221            {222                ErrorRecord errorRecord = new ErrorRecord(223                    e,224                    "INVALID_REGISTRATION",225                    ErrorCategory.InvalidOperation,226                    inputObject);227 228                WriteError(errorRecord);229            }230        }231    }232}233