PSConfig.psm1
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<#
.SYNOPSIS Creates a layer of abstraction above reading configuration data. #> # Load strings file $CurrentPath = Split-Path -Path $MyInvocation.MyCommand.Definition -Parent Import-LocalizedData -BindingVariable r -BaseDirectory (Join-Path -Path $CurrentPath -ChildPath "Localized") $Script:r = $r # This array keeps track of all the configuration sources that have been added. $Script:ConfigurationSources = @() Function Get-ConfigurationItem { <# .SYNOPSIS Gets a piece of configuration data from the first source that contains the specified key. .DESCRIPTION Gets a piece of configuration data from the first source that contains the specified key. Configuration sources are searched in the order in which they were loaded. .PARAMETER Key Specifies the key to retrieve a value for. .OUTPUTS Variant. The output type depends on the contents of the configuration data. #> [CmdletBinding()] Param ( [Parameter(Mandatory = $true)] [string]$Key ) Process { $ReturnValue = $null foreach ($Item in $Script:ConfigurationSources) { Write-Verbose -Message ([string]::Format($Script:r.SearchingForItem_F0_In_F1_Type_F2, $Key, $Item.Name, $Item.Type)) if ($Item.Type -eq "Environment") { if (Test-Path -Path "Env:\$Key") { Write-Verbose -Message ([string]::Format($Script:r.Item_F0_Found, $Key)) $ReturnValue = (Get-Item -Path "Env:\$Key").Value break } } else { $Property = $Item.Data.PSObject.Properties | Where-Object -FilterScript { $_.Name -eq $Key } if ($Property) { Write-Verbose -Message ([string]::Format($Script:r.Item_F0_Found, $Key)) $ReturnValue = $Property.Value break } } } return $ReturnValue } } Function Add-DefaultConfigurationSource { <# .SYNOPSIS Adds a configuration source with explicitly specified values. .DESCRIPTION Adds a configuration source with explicitly specified values. This can be useful for specifying fallback values that may not be present in a user's specific configuration. .PARAMETER InputObject Specifies configuration data. .OUTPUTS None. #> [CmdletBinding()] Param ( [Parameter( Mandatory = $true, ValueFromPipeline = $true )] [PSCustomObject[]]$InputObject ) Process { foreach ($Item in $InputObject) { # The data coming in should be a PSCustomObject already, but in case # it's not convert it. if ($Item -is [hashtable]) { $Item = New-Object -TypeName PSObject -Property $Item } $NewSource = New-Object -TypeName PSObject -Property @{ Name = "Default Values" Type = "Default" Data = $Item } Write-Verbose -Message ([string]::Format($Script:r.AddingSource_F0_Type_F1, $NewSource.Name, $NewSource.Type)) $Script:ConfigurationSources += $NewSource } } } Function Add-FileConfigurationSource { <# .SYNOPSIS Adds a configuration source from the specified file. .DESCRIPTION Adds a configuration source from the specified file. Files can be formatted in three different ways: StringData - The file will be imported and passed to ConvertFrom-StringData Json - The file can be parsed using ConvertFrom-Json. Csv - The file can be parsed using Import-Csv. Only the first row will be read. .PARAMETER Path Specifies the path to the configuration file. .PARAMETER Format Specifies the format the configuration file is written in. #> [CmdletBinding()] Param ( [Parameter( Mandatory = $true, ValueFromPipeline = $true, ValueFromPipelineByPropertyName = $true )] [string[]]$Path, [Parameter( ValueFromPipelineByPropertyName = $true )] [ValidateSet("StringData", "Json", "Csv")] [string]$Format = "StringData" ) Process { foreach ($Item in $Path) { if (!(Test-Path -Path $Item)) { # The file may not exist, that's part of making this flexible, # so it's not an error. Write-Verbose -Message ([string]::Format($Script:r.File_F0_NotFound, $Item)) continue } $NewSource = $null switch ($Format) { "StringData" { try { $Data = Get-Content -Path $Item -Raw -ErrorAction Stop | ConvertFrom-StringData -ErrorAction Stop $NewSource = New-Object -TypeName PSObject -Property @{ Type = "File/StringData" Name = $Item Data = $Data } -ErrorAction Stop } catch { Write-Error -Exception $_.Exception -Message ([string]::Format($Script:r.CannotLoad_F0_Data_F1, "StringData", $Item)) } } "Json" { try { $Data = Get-Content -Path $Item -Raw -ErrorAction Stop | ConvertFrom-Json -ErrorAction Stop $NewSource = New-Object -TypeName PSObject -Property @{ Type = "File/Json" Name = $Item Data = $Data } -ErrorAction Stop } catch { Write-Error -Exception $_.Exception -Message ([string]::Format($Script:r.CannotLoad_F0_Data_F1, "Json", $Item)) } } "Csv" { try { $Data = Import-Csv -Path $Item -ErrorAction Stop | Select-Object -First 1 -ErrorAction Stop $NewSource = New-Object -TypeName PSObject -Property @{ Type = "File/Csv" Name = $Item Data = $Data } -ErrorAction Stop } catch { Write-Error -Exception $_.Exception -Message ([string]::Format($Script:r.CannotLoad_F0_Data_F1, "Csv", $Item)) } } } if ($NewSource) { Write-Verbose -Message ([string]::Format($Script:r.AddingSource_F0_Type_F1, $NewSource.Name, $NewSource.Type)) $Script:ConfigurationSources += $NewSource } } } } Function Add-EnvironmentConfigurationSource { <# .SYNOPSIS Adds the current session's environment variables as a configuration source. .DESCRIPTION Adds the current session's environment variables as a configuration source. .OUTPUTS None. #> [CmdletBinding()] Param () Process { $NewSource = New-Object -TypeName PSObject -Property @{ Type = "Environment" Name = "Environment Variables" Data = $null } Write-Verbose -Message ([string]::Format($Script:r.AddingSource_F0_Type_F1, $NewSource.Name, $NewSource.Type)) $Script:ConfigurationSources += $NewSource } } Function Clear-ConfigurationSource { <# .SYNOPSIS Clears all currently loaded configuration sources. .DESCRIPTION Clears all currently loaded configuration sources. .OUTPUTS None. #> [CmdletBinding()] Param () Process { Write-Verbose -Message $Script:r.ClearingSources $Script:ConfigurationSources = @() } } |