GetChildrenCommand.cs

/********************************************************************++
Copyright (c) Microsoft Corporation.  All rights reserved.
--********************************************************************/

using System;
using System.Management.Automation;
using Dbg = System.Management.Automation;

namespace Microsoft.PowerShell.Commands
{
    /// <summary>
    /// The get-childitem command class.
    /// This command lists the contents of a container
    /// </summary>
    ///
    /// <remarks>
    /// </remarks>
    ///
    [Cmdlet(VerbsCommon.Get, "ChildItem", DefaultParameterSetName = "Items", SupportsTransactions = true, HelpUri = "https://go.microsoft.com/fwlink/?LinkID=113308")]
    public class GetChildItemCommand : CoreCommandBase
    {
        /// <summary>
        /// The string declaration for the Items parameter set in this command.
        /// </summary>
        /// <remarks>
        /// The "Items" parameter set includes the following parameters:
        ///     -filter
        ///     -recurse
        /// </remarks>
        private const string childrenSet = "Items";
        private const string literalChildrenSet = "LiteralItems";

#if RELATIONSHIP_SUPPORTED
        // 2004/11/24-JeffJon - Relationships have been removed from the Exchange release

        /// <summary>
        /// The string declaration for the -relationship parameter set.
        /// </summary>
        ///
        /// <remarks>
        /// The "relationship" parameter set includes the following parameters:
        ///     -relationship
        ///     -property
        /// </remarks>
        ///
        private const string relationshipSet = "Relationship";
#endif
        #region Command parameters

        /// <summary>
        /// Gets or sets the path for the operation
        /// </summary>
        [Parameter(Position = 0, ParameterSetName = childrenSet,
                   ValueFromPipeline = true, ValueFromPipelineByPropertyName = true)]
        public string[] Path
        {
            get
            {
                return _paths;
            }
            set
            {
                _paths = value;
            }
        }

        /// <summary>
        /// Gets or sets the literal path parameter to the command
        /// </summary>
        [Parameter(ParameterSetName = literalChildrenSet,
                   Mandatory = true, ValueFromPipeline = false, ValueFromPipelineByPropertyName = true)]
        [Alias("PSPath")]
        public string[] LiteralPath
        {
            get
            {
                return _paths;
            } // get

            set
            {
                base.SuppressWildcardExpansion = true;
                _paths = value;
            } // set
        } // LiteralPath

        /// <summary>
        /// Gets or sets the filter property
        /// </summary>
        [Parameter(Position = 1)]
        public override string Filter
        {
            get
            {
                return base.Filter;
            }
            set
            {
                base.Filter = value;
            }
        }

        /// <summary>
        /// Gets or sets the include property
        /// </summary>
        [Parameter]
        public override string[] Include
        {
            get
            {
                return base.Include;
            } // get

            set
            {
                base.Include = value;
            } // set
        } // Include

        /// <summary>
        /// Gets or sets the exclude property
        /// </summary>
        [Parameter]
        public override string[] Exclude
        {
            get
            {
                return base.Exclude;
            } // get

            set
            {
                base.Exclude = value;
            } // set
        } // Exclude

        /// <summary>
        /// Gets or sets the recurse switch
        /// </summary>
        [Parameter]
        [Alias("s")]
        public SwitchParameter Recurse
        {
            get
            {
                return _recurse;
            }
            set
            {
                _recurse = value;
            }
        }

        /// <summary>
        /// Gets or sets max depth of recursion; automatically sets Recurse parameter;
        /// Value '0' will show only contents of container specified by -Path (same result as running 'Get-ChildItem' without '-Recurse');
        /// Value '1' will show 1 level deep, etc...;
        /// Default is uint.MaxValue - it performs full recursion (this parameter has no effect).
        /// </summary>
        [Parameter]
        public uint Depth
        {
            get
            {
                return _depth;
            }
            set
            {
                _depth = value;
                this.Recurse = true; // Bug 2391925 - Get-ChildItem -Depth should auto-set -Recurse
            }
        }

        /// <summary>
        /// Gets or sets the force property
        /// </summary>
        ///
        /// <remarks>
        /// Gives the provider guidance on how vigorous it should be about performing
        /// the operation. If true, the provider should do everything possible to perform
        /// the operation. If false, the provider should attempt the operation but allow
        /// even simple errors to terminate the operation.
        /// For example, if the user tries to copy a file to a path that already exists and
        /// the destination is read-only, if force is true, the provider should copy over
        /// the existing read-only file. If force is false, the provider should write an error.
        /// </remarks>
        ///
        [Parameter]
        public override SwitchParameter Force
        {
            get
            {
                return base.Force;
            }
            set
            {
                base.Force = value;
            }
        } // Force

        /// <summary>
        /// Gets or sets the names switch
        /// </summary>
        [Parameter]
        public SwitchParameter Name
        {
            get
            {
                return _childNames;
            }
            set
            {
                _childNames = value;
            }
        }

#if RELATIONSHIP_SUPPORTED
        // 2004/11/24-JeffJon - Relationships have been removed from the Exchange release

        /// <summary>
        /// Gets and sets the value of the Relationship parameter which determines
        /// which relationship the targets should be retrieved for.
        /// </summary>
        ///
        [Parameter(
            Mandatory = true,
            ParameterSetName = relationshipSet,
            ValueFromPipelineByPropertyName = true)]
        public string[] Relationship
        {
            get
            {
                return relationships;
            }
            set
            {
                relationships = value;
            }
        }
        private string[] relationships = new string[0];

        /// <summary>
        /// Gets or sets the property parameter which may provide guidance to the relationship
        /// provider on which targets to return.
        /// </summary>
        ///
        [Parameter(ParameterSetName = relationshipSet, ValueFromPipelineByPropertyName = true)]
        public string Property
        {
            get
            {
                return property;
            }

            set
            {
                property = value;
            }
        }
        private string property = String.Empty;
#endif
        /// <summary>
        /// A virtual method for retrieving the dynamic parameters for a cmdlet. Derived cmdlets
        /// that require dynamic parameters should override this method and return the
        /// dynamic parameter object.
        /// </summary>
        ///
        /// <param name="context">
        /// The context under which the command is running.
        /// </param>
        ///
        /// <returns>
        /// An object representing the dynamic parameters for the cmdlet or null if there
        /// are none.
        /// </returns>
        ///
        internal override object GetDynamicParameters(CmdletProviderContext context)
        {
            object result = null;
            string path = String.Empty;

            if (_paths != null && _paths.Length > 0)
            {
                path = _paths[0];
            }
            else
            {
                path = ".";
            }

            switch (ParameterSetName)
            {
                case childrenSet:
                case literalChildrenSet:
                    if (Name)
                    {
                        result = InvokeProvider.ChildItem.GetChildNamesDynamicParameters(path, context);
                    }
                    else
                    {
                        result = InvokeProvider.ChildItem.GetChildItemsDynamicParameters(path, Recurse, context);
                    }
                    break;

#if RELATIONSHIP_SUPPORTED
    // 2004/11/24-JeffJon - Relationships have been removed from the Exchange release

               case relationshipSet:
                    // No possible dynamic parameters for the relationship set.
                    break;
#endif
                default:
                    result = InvokeProvider.ChildItem.GetChildItemsDynamicParameters(path, Recurse, context);
                    break;
            }
            return result;
        } // GetDynamicParameters

        #endregion Command parameters

        #region command data

        /// <summary>
        /// The path for the get-location operation.
        /// </summary>
        private string[] _paths;

        /// <summary>
        /// Determines if the command should do recursion.
        /// </summary>
        private bool _recurse;

        /// <summary>
        /// Limits the depth of recursion; used with Recurse parameter;
        /// Value '0' will show only contents of container specified by -Path (same result as running 'Get-ChildItem' without '-Recurse');
        /// Value '1' will show 1 level deep, etc...;
        /// Default is uint.MaxValue - it performs full recursion (this parameter has no effect).
        /// </summary>
        private uint _depth = uint.MaxValue;

        /// <summary>
        /// The flag that specifies whether to retrieve the child names or the child items
        /// </summary>
        private bool _childNames = false;

        #endregion command data


        #region command code

        /// <summary>
        /// The main execution method for the get-childitem command.
        /// </summary>
        protected override void ProcessRecord()
        {
            CmdletProviderContext currentContext = CmdletProviderContext;

            if (_paths == null ||
                (_paths != null && _paths.Length == 0))
            {
                _paths = new string[] { String.Empty };
            }

            foreach (string path in _paths)
            {
                switch (ParameterSetName)
                {
                    case childrenSet:
                    case literalChildrenSet:
                        try
                        {
                            if (Name)
                            {
                                // Get the names of the child items using the static namespace method.
                                // The child names should be written directly to the pipeline using the
                                // context.WriteObject method.

                                InvokeProvider.ChildItem.GetNames(path, ReturnContainers.ReturnMatchingContainers, Recurse, Depth, currentContext);
                            }
                            else
                            {
                                // Get the children using the static namespace method.
                                // The children should be written directly to the pipeline using
                                // the context.WriteObject method.

                                InvokeProvider.ChildItem.Get(path, Recurse, Depth, currentContext);
                            }
                        }
                        catch (PSNotSupportedException notSupported)
                        {
                            WriteError(
                                new ErrorRecord(
                                    notSupported.ErrorRecord,
                                    notSupported));
                            continue;
                        }
                        catch (DriveNotFoundException driveNotFound)
                        {
                            WriteError(
                                new ErrorRecord(
                                    driveNotFound.ErrorRecord,
                                    driveNotFound));
                            continue;
                        }
                        catch (ProviderNotFoundException providerNotFound)
                        {
                            WriteError(
                                new ErrorRecord(
                                    providerNotFound.ErrorRecord,
                                    providerNotFound));
                            continue;
                        }
                        catch (ItemNotFoundException pathNotFound)
                        {
                            WriteError(
                                new ErrorRecord(
                                    pathNotFound.ErrorRecord,
                                    pathNotFound));
                            continue;
                        }

                        break;

#if RELATIONSHIP_SUPPORTED
    // 2004/11/24-JeffJon - Relationships have been removed from the Exchange release

                    case relationshipSet:
                        foreach (string relationship in relationships)
                        {
                            Collection<string> results = null;

                            try
                            {
                                results =
                                    InvokeProvider.Relationship.GetTargets(
                                        relationship,
                                        path,
                                        property);
                            }
                            catch (PSArgumentException argException)
                            {
                                WriteError(
                                    new ErrorRecord(
                                        argException.ErrorRecord,
                                        argException));
                                continue;
                            }
                            catch (ProviderNotFoundException providerNotFound)
                            {
                                WriteError(
                                    new ErrorRecord(
                                        providerNotFound.ErrorRecord,
                                        providerNotFound));
                                continue;
                            }

                            foreach (string target in results)
                            {
                                // Create an PSObject with the result.
                                // Attach the relationship name as a note,
                                // and set "System.Management.Automation.RelationshipTarget"
                                // as the TreatAs.

                                PSObject result = PSObject.AsPSObject (target);
                                result.Properties.Add (
                                    new PSNoteProperty (
                                        "Relationship",
                                        relationship));

                                Collection<string> treatAs = new Collection<string> ();
                                treatAs.Add (targetTreatAsType);

                                result.TypeNames = treatAs;

                                // Now write out the result
                                WriteObject (result);
                            }
                        }
                        break;
#endif
                    default:
                        Dbg.Diagnostics.Assert(
                            false,
                            "Only one of the specified parameter sets should be called.");
                        break;
                }
            }
        } // ProcessRecord

#if RELATIONSHIP_SUPPORTED
        // 2004/11/24-JeffJon - Relationships have been removed from the Exchange release

        private const string targetTreatAsType = "System.Management.Automation.RelationshipTarget";
#endif
        #endregion command code
    } // class GetChildrenCommand
} // namespace Microsoft.PowerShell.Commands