DefaultParameter

1.6

DefaultParameter.psm1

# DefaultParameters Module
# 1.6 - first gallery version
# 1.5 - change .ContainsKey to .Contains because PS5
# 1.4 - removed extra parameter set to get parameter binding working better
# - added default aliases (sdp/gdp/rmdp)
#requires -version 3.0
# 1.3 - fixed denable/disable, added get and remove, and improved import and set
# 1.2 - added help and commands to enable/disable the defaults
# 1.0 - initial release

function Export-DefaultParameter {
    #.Synopsis
    # Exports the current default parameter values
    [CmdletBinding()]
    param(
        # The path to export default parameter values to (defaults to "DefaultParameterValues.clixml" in your profile directory)
        [String]$Path = $(Join-Path (Split-Path $Profile.CurrentUserAllHosts -Parent) DefaultParameterValues.clixml)
    )
    Export-CliXml -InputObject $Global:PSDefaultParameterValues -Path $Path
}

function Import-DefaultParameter {
    #.Synopsis
    # Imports new default parameter values
    [CmdletBinding()]
    param(
        # The path to import default parameter values from (defaults to "DefaultParameterValues.clixml" in your profile directory)
        [String]$Path = $(Join-Path (Split-Path $Profile.CurrentUserAllHosts -Parent) DefaultParameterValues.clixml),
        # If set, overwrite current values (otherwise, keep current values)
        [Switch]$Force
    )
    $TempParameterValues = $Global:PSDefaultParameterValues
    if(Test-Path $Path) {
        [System.Management.Automation.DefaultParameterDictionary]$NewValues = 
                Import-CliXml -Path ${ProfileDir}\DefaultParameterValues.clixml
          
        $repeats = @()
        foreach($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
            }
        }
        if($repeats.Count) {
            $Width = &{
                $Local:ErrorActionPreference = "SilentlyContinue"
                $Width = $Host.UI.RawUI.BufferSize.Width - 2
                if($Width) { $Width } else { 80 }
            }
            if($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"] = $false
    } else {
        Write-Warning "Default Parameter cache not found: '$Path'"
    }
}

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
    [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 $command | Select -First 1
    while($cmd.CommandType -eq "Alias") {
        $cmd = Get-Command $cmd.Definition | Select -First 1
    }
    $parameters = $cmd.Parameters.Values
    $param = @($parameters | Where-Object { $_.Name -match $parameter -or $_.Aliases -match $parameter} | Select -Expand Name -Unique)
    if(!$param) {
        $param = @($parameters | Where-Object { $_.Name -match "${parameter}*"} | Select -First 1 -Expand Name)
        if(!$param) {
            $param = @($parameters | Where-Object { $_.Aliases -match "${parameter}*"} | Select -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, $CI, "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 $PSDefaultParameterValues
    [CmdletBinding()]
    param(
        # The command that you want to change the default value of a parameter for (allows wildcards)
        [parameter(Position=0,Mandatory=$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 ":"
            $repeats += [PSCustomObject]@{Command=$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 $PSDefaultParameterValues
    [CmdletBinding(SupportsShouldProcess=$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 { $_ -like "${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
}

Set-Alias Add-DefaultParameter Set-DefaultParameter -ErrorAction SilentlyContinue
Set-Alias sdp Set-DefaultParameter -ErrorAction SilentlyContinue
Set-Alias gdp Get-DefaultParameter -ErrorAction SilentlyContinue
Set-Alias rmdp Remove-DefaultParameter -ErrorAction SilentlyContinue
Set-Alias ipdp Import-DefaultParameter -ErrorAction SilentlyContinue
Set-Alias exdp Export-DefaultParameter -ErrorAction SilentlyContinue
# Set-Alias ddp Disable-DefaultParameter -ErrorAction SilentlyContinue
# Set-Alias edp Disable-DefaultParameter -ErrorAction SilentlyContinue
Import-DefaultParameter -WarningAction SilentlyContinue

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