DefaultParameter

2.0.0

DefaultParameter.psm1

function Export-DefaultParameter {
    #.Synopsis
    # Exports the current default parameter values
    [Alias("epdp", "exdp")]
    [CmdletBinding()]
    param(
        # The path to export default parameter values to (defaults to "DefaultParameterValues.clixml" in your profile directory)
        [String]$Path
    )
    if ($Path) {
        Export-Clixml -Path $Path -InputObject $Global:PSDefaultParameterValues
    }

    Export-Configuration -InputObject $Global:PSDefaultParameterValues
}

function UpdateDefaultParameter {
    <#
        .Synopsis
            Updates $Global:PSDefaultParameterValues from a DefaultParameterDictionary
    #>
    [CmdletBinding()]
    param(
        [System.Management.Automation.DefaultParameterDictionary]$NewValues
    )

    $repeats = @()

    foreach ($key in $NewValues.Keys) {
        # don't import the disabled state, that's just silly
        if ($key -eq "disabled") {
            continue
        }
        if ($Global:PSDefaultParameterValues.Contains($key)) {
            $command, $parameter = $key -split ":"
            if ($Force) {
                $repeats += [PSCustomObject]@{
                    Command    = $Command
                    Parameter  = $Parameter
                    NewDefault = $NewValues[$key]
                    OldDefault = $Global:PSDefaultParameterValues[$Key]
                }

                $Global:PSDefaultParameterValues[$Key] = $NewValues[$key]

            } else {
                $repeats += [PSCustomObject]@{
                    Command        = $Command
                    Parameter      = $Parameter
                    CurrentDefault = $Global:PSDefaultParameterValues[$Key]
                    SkippedValue   = $NewValues[$key]
                }
            }
        } else {
            $Global:PSDefaultParameterValues[$Key] = $NewValues[$key]
        }
    }

    $repeats
}

function Import-DefaultParameter {
    #.Synopsis
    # Imports new default parameter values
    [Alias("ipdp")]
    [CmdletBinding()]
    param(
        # The path to import default parameter values from (defaults to "DefaultParameterValues.clixml" in your profile directory)
        [String]$Path,
        # If set, overwrite current values (otherwise, keep current values)
        [Switch]$Force
    )
    $repeats = @()

    if ($Path -and (Test-Path $Path)) {
        [System.Management.Automation.DefaultParameterDictionary]$NewValues = Import-CliXml -Path $Path
        $repeats += UpdateDefaultParameter $NewValues
    }

    [System.Management.Automation.DefaultParameterDictionary]$NewValues = Import-Configuration
    $repeats += UpdateDefaultParameter $NewValues

    if ($repeats.Count) {
        $Width = & {
            $Local:ErrorActionPreference = "SilentlyContinue"
            if (($Width = $Host.UI.RawUI.BufferSize.Width - 2)) {
                $Width
            } else {
                80
            }
        }
        if ($Force) {
            Write-Warning ("Some defaults overwritten:`n{0}" -f ($repeats | Out-String -Width $Width))
        } else {
            Write-Warning ("Some defaults already defined, use -Force to overwrite:`n{0}" -f ($repeats | Out-String -Width $Width))
        }
    }
    # Make sure that everything is enabled
    $Global:PSDefaultParameterValues["Disabled"] = $false
}

function Set-DefaultParameter {
    #.Synopsis
    # Sets a default parameter value for a command
    #.Description
    # Safely sets the default parameter value for a command, making sure that you've correctly typed the command and parameter combination
    [Alias("sdp", "Add-DefaultParameter")]
    [CmdletBinding(SupportsShouldProcess = $true, ConfirmImpact = "Low")]
    param(
        # The command that you want to change the default value of a parameter for
        [parameter(Position = 0, Mandatory = $true)]
        $Command,
        # The name of the parameter that you want to change the default value for
        [parameter(Position = 1, Mandatory = $true)]
        [String]$Parameter,
        # The new default parameter value
        [parameter(Position = 2, Mandatory = $true)]
        $Value
    )
    Write-Verbose ($PSBoundParameters | Out-String)

    if ($parameter.StartsWith("-")) {
        $parameter = $parameter.TrimStart("-")
    }

    ## Resolve the parameter to be sure
    $cmd = Get-Command $command | Select-Object -First 1
    while ($cmd.CommandType -eq "Alias") {
        $cmd = Get-Command $cmd.Definition | Select-Object -First 1
    }
    $parameters = $cmd.Parameters.Values
    $param = @(
        $parameters |
            Where-Object { $_.Name -match $parameter -or $_.Aliases -match $parameter } |
            Select-Object -Expand Name -Unique
    )
    if (!$param) {
        $param = @(
            $parameters |
                Where-Object { $_.Name -match "${parameter}*" } |
                Select-Object -First 1 -Expand Name
        )
        if (!$param) {
            $param = @(
                $parameters |
                    Where-Object { $_.Aliases -match "${parameter}*" } |
                    Select-Object -First 1 -Expand Name
            )
        }
    }
    if ($param.Count -gt 1 -and $param -eq $parameter) {
        $param = @($param -eq $parameter)
    }
    if ($param.Count -gt 1) {
        Write-Warning "Please specify the full parameter name: '$parameter' matches '$($param -join "', '")'"
    } elseif ($param.Count -eq 1) {
        $Command = $Cmd.Name
        Write-Verbose "Setting Parameter $parameter on ${Command} to default: $($param[0])"

        $Key = "${Command}:$($param[0])"
        if ($Global:PSDefaultParameterValues.Contains($Key) ) {
            $WI = "Overwrote the default parameter value for '$Key' with $Value"
            $CF = "Overwrite the existing default parameter value for '$Key'? ($($Global:PSDefaultParameterValues[$Key]))"
        } else {
            $WI = "Added a default parameter value for '$Key' = $Value"
            $CF = "Add a default parameter value for '$Key'? ($($Global:PSDefaultParameterValues[$Key]))"
        }
        if ($PSCmdlet.ShouldProcess( $WI, $CF, "Setting Default Parameter Values" )) {
            $Global:PSDefaultParameterValues[$Key] = $Value
        }
    } else {
        Write-Warning "Parameter $parameter not found on ${Command}"
    }
}

function Get-DefaultParameter {
    #.Synopsis
    # Gets the default parameter value for a command, if it's been set
    #.Description
    # Gets the default parameter value for a command from $PSDefaultParameterValues
    [Alias("gdp")]
    [CmdletBinding()]
    param(
        # The command that you want to change the default value of a parameter for (allows wildcards)
        [parameter(Position = 0, Mandatory = $false)]
        [string]$Command = "*",

        # The name of the parameter that you want to change the default value for (allows wildcards)
        [parameter(Position = 1, Mandatory = $false)]
        [string]$Parameter = "*"
    )

    if ($parameter.StartsWith("-")) {
        $parameter = $parameter.TrimStart("-")
    }

    $repeats = @()
    foreach ($key in $Global:PSDefaultParameterValues.Keys) {
        # Handle the disabled state:
        if ($key -eq "disabled" -and $Global:PSDefaultParameterValues["Disabled"]) {
            Write-Warning "Default Parameter Values are DISABLED and will not be used:"
            continue
        }
        if ($key -like "${Command}:${Parameter}*") {
            $Cmd, $Param = $key -split ":",2
            $repeats += [PSCustomObject]@{Command = $Cmd; Parameter = $Param; CurrentDefault = $Global:PSDefaultParameterValues[$Key] }
        } else {
            Write-Verbose "'$key' is -not -like '${Command}:${Parameter}*'"
        }
    }
    $repeats
}

function Remove-DefaultParameter {
    #.Synopsis
    # Removed the default parameter value for a command, if it's been set
    #.Description
    # Removes the default parameter value for a command from $PSDefaultParameterValues
    [Alias("rdp", "rmdp")]
    [CmdletBinding(SupportsShouldProcess = $true, ConfirmImpact = "Low")]
    param(
        # The command that you want to change the default value of a parameter for (allows wildcards)
        [parameter(Position = 0, Mandatory = $false)]
        [string]$Command = "*",

        # The name of the parameter that you want to change the default value for (allows wildcards)
        [parameter(Position = 1, Mandatory = $true)]
        [string]$Parameter
    )

    if ($parameter.StartsWith("-")) {
        $parameter = $parameter.TrimStart("-")
    }

    $keys
    foreach ($key in $Global:PSDefaultParameterValues.Keys | Where-Object { $_ -like "${Command}:${Parameter}*" }) {
        # Handle the disabled state:
        if ($key -ne "disabled") {
            if ($PSCmdlet.ShouldProcess( "Removed the default parameter value for '$Key'",
                    "Remove the default parameter value for '$Key'?",
                    "Removing Default Parameter Values" )) {
                $Global:PSDefaultParameterValues.Remove($key)
            }
        }
    }
}

function Disable-DefaultParameter {
    #.Synopsis
    # Turns OFF default parameters
    #.Description
    # By setting $PSDefaultParameterValues["Disabled"] to $true, we make sure that NONE of our default parameter values will be used
    [CmdletBinding()]
    param()
    $Global:PSDefaultParameterValues["Disabled"] = $true
}

function Enable-DefaultParameter {
    #.Synopsis
    # Turns ON default parameters
    #.Description
    # By setting $PSDefaultParameterValues["Disabled"] to $false, we make sure that all of our default parameter values will be used
    [CmdletBinding()]
    param()
    $Global:PSDefaultParameterValues["Disabled"] = $false
}

# First time migration from 1.x
$OldPath = $(Join-Path (Split-Path $Profile.CurrentUserAllHosts -Parent) DefaultParameterValues.clixml)
if (Test-Path $OldPath) {
    Import-DefaultParameter -Path $OldPath -ErrorVariable Problem
    if (!$Problem) {
        Write-Warning "One-time migration of DefaultParameterValues configuration complete. Please verify `$PSDefaultParameterValues and then delete the old file by running: Remove-Item '$OldPath'"
        Export-DefaultParameter
    }
} else {
    Import-DefaultParameter -WarningAction SilentlyContinue
}

Export-ModuleMember -Alias * -Function Set-DefaultParameter, Get-DefaultParameter, Remove-DefaultParameter, `
    Import-DefaultParameter, Export-DefaultParameter, `
    Enable-DefaultParameter, Disable-DefaultParameter