PoweShell: Casting the data type for properties in Select-Object

Question

I'm looking for a more efficient method (for both typing time and performance) of casting data types during a PowerShell Select-Object.

Currently, I am wrapping each individual property in an expression to cast the data type. I'm confident this isn't the correct way to do this, it just feels dirty...

The reason I am doing this is that I'm sending the data to a REST API which is applying strict validation using a JSON schema. The data in $Data is unreliable. For example, a property is sometimes a JSON string "12345" and occasionally an unexpected JSON Integer 12345.

The REST API then returns a 403 error because it was not expecting an Integer for that key.

$Results = $Data | select ` 
    @{Name = 'Name'; expression = {[string]$_.DisplayName}}, 
    @{Name = 'Version'; expression = {[string]$_.DisplayVersion}},  
    @{Name = 'HelpLink'; expression = {[string]$_.HelpLink}}, 
    @{Name = 'InstallLocation'; expression = {[string]$_.InstallLocation}}, 
    @{Name = 'InstallSource'; expression = {[string]$_.InstallSource}}, 
    @{Name = 'Language'; expression = {[int]$_.Language}},  
    @{Name = 'DisplayIcon'; expression = {[string]$_.DisplayIcon}}, 
    @{Name = 'UninstallString'; expression = {[string]$_.UninstallString}}, 
    @{Name = 'WindowsInstaller'; expression = {[int]$_.WindowsInstaller}},
    @{Name = 'AppGUID'; expression = {[string]$_.APP_GUID}},  
    @{Name = 'URLInfoAbout'; expression = {[string]$_.URLInfoAbout}}, 
    @{Name = 'Vendor'; expression = {[string]$_.Publisher}}, 
    @{Name = 'InstallDate'; expression = {[int]$_.InstallDate}},
    @{Name = 'EstimatedSize'; expression = {[int]$_.EstimatedSize}},
    @{Name = 'VersionMajor'; expression = {[string]$_.VersionMajor}},
    @{Name = 'VersionMinor'; expression = {[string]$_.VersionMinor}},
    @{Name = 'SystemComponent'; expression = {[int]$_.SystemComponent}},
    @{Name = 'NoModify'; expression = {[string]$_.NoModify}},
    @{Name = 'NoRepair'; expression = {[string]$_.NoRepair}},
    @{Name = 'ModifyPath'; expression = {[string]$_.ModifyPath}},
    @{Name = 'BundleVersion'; expression = {[string]$_.BundleVersion}},
    @{Name = 'EngineVersion'; expression = {[string]$_.EngineVersion}}

Answer 1

I would only cast the properties that need to be of type int. Since PowerShell is a language based on dynamic typing, so you can do the following:

$obj = [PSCustomObject] @{ Number = "123" }
$obj.Number.GetType() # Type is string
$obj.Number = [int] $obj.Number
$obj.Number.GetType() # Type is int

Output:
IsPublic IsSerial Name                                     BaseType
-------- -------- ----                                     --------
True     True     String                                   System.Object
True     True     Int32                                    System.ValueType

You can find this sample online. So, you should be able to use this approach:

$Data.Language =  [int] $Data.Language

In short, you've cast the properties that need to be of type int.

UPDATE 1

If your object have a "flat" hirarchy you can try the following:

$obj = [PSCustomObject]@{
    IntNr = "123"
    DecNr = "4,56"
    Str   = "abc"
}

$result = $obj.PSObject.Properties | ForEach-Object {
    [int] $parsedInt = 0
    [decimal] $parsedDec = 0.0
    if ([int]::TryParse($_.Value, [ref]$parsedInt)) {
        $_.Value = $parsedInt
    }
    elseif ([decimal]::TryParse($_.Value, [ref]$parsedDec)) {
        $_.Value = $parsedDec
    }
    $_
}

$result

Output when dumping $result:

 Value           : 123
 MemberType      : NoteProperty
 IsSettable      : True
 IsGettable      : True
 TypeNameOfValue : System.Int32
 Name            : IntNr
 IsInstance      : True

 Value           : 456
 MemberType      : NoteProperty
 IsSettable      : True
 IsGettable      : True
 TypeNameOfValue : System.Decimal
 Name            : DecNr
 IsInstance      : True

 Value           : abc
 MemberType      : NoteProperty
 IsSettable      : True
 IsGettable      : True
 TypeNameOfValue : System.String
 Name            : Str
 IsInstance      : True

The sample is available online under this link.