Source/Public/ConvertFrom-Expression.ps1
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<#
.SYNOPSIS Deserializes a PowerShell expression to an object. .DESCRIPTION The `ConvertFrom-Expression` cmdlet converts a PowerShell formatted expression to an object-graph existing of a mixture of nested arrays, hashtables and objects that contain a list of strings and values. .PARAMETER InputObject Specifies the PowerShell expressions to convert to objects. Enter a variable that contains the string, or type a command or expression that gets the string. You can also pipe a string to ConvertFrom-Expression. The **InputObject** parameter is required, but its value can be an empty string. The **InputObject** value can't be `$null` or an empty string. .PARAMETER LanguageMode Defines which object types are allowed for the deserialization, see: [About language modes][2] * Any type that is not allowed by the given language mode, will be omitted leaving a bare `[ValueType]`, `[String]`, `[Array]` or `[HashTable]`. * Any variable that is not `$True`, `$False` or `$Null` will be converted to a literal string, e.g. `$Test`. > [!Caution] > > In full language mode the concerned string will simply be invoke using [Invoke-Expression]. > > Take reasonable precautions when using the Invoke-Expression cmdlet in scripts. When using > `-LanguageMode Full` to run a command that the user enters, verify that the command is safe to run > before running it. In general, it is best to design your script with predefined input options, > rather than allowing freeform input. #> function ConvertFrom-Expression { [CmdletBinding()][OutputType([Object])] param( [Parameter(Mandatory = $true, ValueFromPipeLine = $True)] [Alias('Expression')][String]$InputObject, [ValidateScript({ $_ -ne 'NoLanguage' })] [PSLanguageMode]$LanguageMode = 'Restricted' ) begin { function StopError($Exception, $Id = 'IncorrectArgument', $Group = [Management.Automation.ErrorCategory]::SyntaxError, $Object){ if ($Exception -is [System.Management.Automation.ErrorRecord]) { $Exception = $Exception.Exception } elseif ($Exception -isnot [Exception]) { $Exception = [ArgumentException]$Exception } $PSCmdlet.ThrowTerminatingError([System.Management.Automation.ErrorRecord]::new($Exception, $Id, $Group, $Object)) } if ($this.LanguageMode -eq 'NoLanguage') { Throw 'The language mode "NoLanguage" is not supported.' } } process { [PSDeserialize]::new($InputObject, $LanguageMode).Object } } |