MegaBites-AI/Windows-powershell

1// Copyright (c) Microsoft Corporation.2// Licensed under the MIT License.3 4using System.Collections;5using System.Collections.ObjectModel;6using System.Management.Automation;7using System.Management.Automation.Provider;8 9using Dbg = System.Management.Automation;10 11namespace Microsoft.PowerShell.Commands12{13    /// <summary>14    /// This provider is the data accessor for shell functions. It uses15    /// the SessionStateProviderBase as the base class to produce a view on16    /// session state data.17    /// </summary>18    [CmdletProvider(FunctionProvider.ProviderName, ProviderCapabilities.ShouldProcess)]19    [OutputType(typeof(FunctionInfo), ProviderCmdlet = ProviderCmdlet.SetItem)]20    [OutputType(typeof(FunctionInfo), ProviderCmdlet = ProviderCmdlet.RenameItem)]21    [OutputType(typeof(FunctionInfo), ProviderCmdlet = ProviderCmdlet.CopyItem)]22    [OutputType(typeof(FunctionInfo), ProviderCmdlet = ProviderCmdlet.GetChildItem)]23    [OutputType(typeof(FunctionInfo), ProviderCmdlet = ProviderCmdlet.GetItem)]24    [OutputType(typeof(FunctionInfo), ProviderCmdlet = ProviderCmdlet.NewItem)]25    public sealed class FunctionProvider : SessionStateProviderBase26    {27        /// <summary>28        /// Gets the name of the provider.29        /// </summary>30        public const string ProviderName = "Function";31 32        #region Constructor33 34        /// <summary>35        /// The constructor for the provider that exposes variables to the user36        /// as drives.37        /// </summary>38        public FunctionProvider()39        {40        }41 42        #endregion Constructor43 44        #region DriveCmdletProvider overrides45 46        /// <summary>47        /// Initializes the function drive.48        /// </summary>49        /// <returns>50        /// An array of a single PSDriveInfo object representing the functions drive.51        /// </returns>52        protected override Collection<PSDriveInfo> InitializeDefaultDrives()53        {54            string description = SessionStateStrings.FunctionDriveDescription;55 56            PSDriveInfo functionDrive =57                new PSDriveInfo(58                    DriveNames.FunctionDrive,59                    ProviderInfo,60                    string.Empty,61                    description,62                    null);63 64            Collection<PSDriveInfo> drives = new Collection<PSDriveInfo>();65            drives.Add(functionDrive);66            return drives;67        }68 69        #endregion DriveCmdletProvider overrides70 71        #region Dynamic Parameters72 73        /// <summary>74        /// Gets the dynamic parameters for the NewItem cmdlet.75        /// </summary>76        /// <param name="path">77        /// Ignored.78        /// </param>79        /// <param name="type">80        /// Ignored.81        /// </param>82        /// <param name="newItemValue">83        /// Ignored.84        /// </param>85        /// <returns>86        /// An instance of FunctionProviderDynamicParameters which is the dynamic parameters for87        /// NewItem.88        /// </returns>89        protected override object NewItemDynamicParameters(string path, string type, object newItemValue)90        {91            return new FunctionProviderDynamicParameters();92        }93 94        /// <summary>95        /// Gets the dynamic parameters for the NewItem cmdlet.96        /// </summary>97        /// <param name="path">98        /// Ignored.99        /// </param>100        /// <param name="value">101        /// Ignored.102        /// </param>103        /// <returns>104        /// An instance of FunctionProviderDynamicParameters which is the dynamic parameters for105        /// SetItem.106        /// </returns>107        protected override object SetItemDynamicParameters(string path, object value)108        {109            return new FunctionProviderDynamicParameters();110        }111 112        #endregion Dynamic Parameters113 114        #region protected members115 116        /// <summary>117        /// Gets a function from session state.118        /// </summary>119        /// <param name="name">120        /// The name of the function to retrieve.121        /// </param>122        /// <returns>123        /// A ScriptBlock that represents the function.124        /// </returns>125        internal override object GetSessionStateItem(string name)126        {127            Dbg.Diagnostics.Assert(128                !string.IsNullOrEmpty(name),129                "The caller should verify this parameter");130 131            CommandInfo function = SessionState.Internal.GetFunction(name, Context.Origin);132 133            return function;134        }135 136        /// <summary>137        /// Sets the function of the specified name to the specified value.138        /// </summary>139        /// <param name="name">140        /// The name of the function to set.141        /// </param>142        /// <param name="value">143        /// The new value for the function.144        /// </param>145        /// <param name="writeItem">146        /// If true, the item that was set should be written to WriteItemObject.147        /// </param>148#pragma warning disable 0162149        internal override void SetSessionStateItem(string name, object value, bool writeItem)150        {151            Dbg.Diagnostics.Assert(152                !string.IsNullOrEmpty(name),153                "The caller should verify this parameter");154 155            FunctionProviderDynamicParameters dynamicParameters =156                DynamicParameters as FunctionProviderDynamicParameters;157 158            CommandInfo modifiedItem = null;159 160            bool dynamicParametersSpecified = dynamicParameters != null && dynamicParameters.OptionsSet;161 162            if (value == null)163            {164                // If the value wasn't specified but the options were, just set the165                // options on the existing function.166                // If the options weren't specified, then remove the function167 168                if (dynamicParametersSpecified)169                {170                    modifiedItem = (CommandInfo)GetSessionStateItem(name);171 172                    if (modifiedItem != null)173                    {174                        SetOptions(modifiedItem, dynamicParameters.Options);175                    }176                }177                else178                {179                    RemoveSessionStateItem(name);180                }181            }182            else183            {184                do // false loop185                {186                    // Unwrap the PSObject before binding it as a scriptblock...187                    PSObject pso = value as PSObject;188                    if (pso != null)189                    {190                        value = pso.BaseObject;191                    }192 193                    ScriptBlock scriptBlockValue = value as ScriptBlock;194                    if (scriptBlockValue != null)195                    {196                        if (dynamicParametersSpecified)197                        {198                            modifiedItem = SessionState.Internal.SetFunction(name, scriptBlockValue,199                                null, dynamicParameters.Options, Force, Context.Origin);200                        }201                        else202                        {203                            modifiedItem = SessionState.Internal.SetFunction(name, scriptBlockValue, null, Force, Context.Origin);204                        }205 206                        break;207                    }208 209                    FunctionInfo function = value as FunctionInfo;210                    if (function != null)211                    {212                        ScopedItemOptions options = function.Options;213 214                        if (dynamicParametersSpecified)215                        {216                            options = dynamicParameters.Options;217                        }218 219                        modifiedItem = SessionState.Internal.SetFunction(name, function.ScriptBlock, function, options, Force, Context.Origin);220                        break;221                    }222 223                    string stringValue = value as string;224                    if (stringValue != null)225                    {226                        ScriptBlock scriptBlock = ScriptBlock.Create(Context.ExecutionContext, stringValue);227 228                        if (dynamicParametersSpecified)229                        {230                            modifiedItem = SessionState.Internal.SetFunction(name, scriptBlock, null, dynamicParameters.Options, Force, Context.Origin);231                        }232                        else233                        {234                            modifiedItem = SessionState.Internal.SetFunction(name, scriptBlock, null, Force, Context.Origin);235                        }236 237                        break;238                    }239 240                    throw PSTraceSource.NewArgumentException(nameof(value));241                } while (false);242 243                if (writeItem && modifiedItem != null)244                {245                    WriteItemObject(modifiedItem, modifiedItem.Name, false);246                }247            }248        }249#pragma warning restore 0162250 251        private static void SetOptions(CommandInfo function, ScopedItemOptions options)252        {253            ((FunctionInfo)function).Options = options;254        }255 256        /// <summary>257        /// Removes the specified function from session state.258        /// </summary>259        /// <param name="name">260        /// The name of the function to remove from session state.261        /// </param>262        internal override void RemoveSessionStateItem(string name)263        {264            Dbg.Diagnostics.Assert(265                !string.IsNullOrEmpty(name),266                "The caller should verify this parameter");267 268            SessionState.Internal.RemoveFunction(name, Force);269        }270 271        /// <summary>272        /// Since items are often more than their value, this method should273        /// be overridden to provide the value for an item.274        /// </summary>275        /// <param name="item">276        /// The item to extract the value from.277        /// </param>278        /// <returns>279        /// The value of the specified item.280        /// </returns>281        /// <remarks>282        /// The default implementation will get283        /// the Value property of a DictionaryEntry284        /// </remarks>285        internal override object GetValueOfItem(object item)286        {287            Dbg.Diagnostics.Assert(288                item != null,289                "Caller should verify the item parameter");290 291            object value = item;292 293            FunctionInfo function = item as FunctionInfo;294            if (function != null)295            {296                value = function.ScriptBlock;297            }298 299            return value;300        }301 302        /// <summary>303        /// Gets a flattened view of the functions in session state.304        /// </summary>305        /// <returns>306        /// An IDictionary representing the flattened view of the functions in307        /// session state.308        /// </returns>309        internal override IDictionary GetSessionStateTable()310        {311            return (IDictionary)SessionState.Internal.GetFunctionTable();312        }313 314        /// <summary>315        /// Determines if the item can be renamed. Derived classes that need316        /// to perform a check should override this method.317        /// </summary>318        /// <param name="item">319        /// The item to verify if it can be renamed.320        /// </param>321        /// <returns>322        /// true if the item can be renamed or false otherwise.323        /// </returns>324        internal override bool CanRenameItem(object item)325        {326            bool result = false;327 328            FunctionInfo functionInfo = item as FunctionInfo;329            if (functionInfo != null)330            {331                if ((functionInfo.Options & ScopedItemOptions.Constant) != 0 ||332                    ((functionInfo.Options & ScopedItemOptions.ReadOnly) != 0 && !Force))333                {334                    SessionStateUnauthorizedAccessException e =335                        new SessionStateUnauthorizedAccessException(336                            functionInfo.Name,337                            SessionStateCategory.Function,338                            "CannotRenameFunction",339                            SessionStateStrings.CannotRenameFunction);340 341                    throw e;342                }343 344                result = true;345            }346 347            return result;348        }349 350        #endregion protected members351    }352 353    /// <summary>354    /// The dynamic parameter object for the FunctionProvider SetItem and NewItem commands.355    /// </summary>356    public class FunctionProviderDynamicParameters357    {358        /// <summary>359        /// Gets or sets the option parameter for the function.360        /// </summary>361        [Parameter]362        public ScopedItemOptions Options363        {364            get365            {366                return _options;367            }368 369            set370            {371                _optionsSet = true;372                _options = value;373            }374        }375 376        private ScopedItemOptions _options = ScopedItemOptions.None;377 378        /// <summary>379        /// Determines if the Options parameter was set.380        /// </summary>381        /// <value></value>382        internal bool OptionsSet383        {384            get { return _optionsSet; }385        }386 387        private bool _optionsSet;388    }389}390