Unable to evaluate against a specific value - powershell

Question

I am having trouble thinking of the correct logic on how to go about this. I have a function that accepts two types of switches:
-Add
-Remove
Function Test-Bool {
Param (
# Input Parameters
[Parameter(Mandatory = $false,
HelpMessage='Enter. Workflow. Name.')]
[Alias('OMB','MailBox')]
[string]$Workflow,
[Parameter(Mandatory = $false)]
[Alias('EDIPI','DisplayName')]
[string[]]$UserName
)
DynamicParam {
if ($Workflow -ne $null -and $UserName -ne $null) {
$parameterAttribute = [System.Management.Automation.ParameterAttribute]#{
ParameterSetName = "AddingMembers"
Mandatory = $false
}
$attributeCollection = [System.Collections.ObjectModel.Collection[System.Attribute]]::new()
$attributeCollection.Add($parameterAttribute)
$dynParam1 = [System.Management.Automation.RuntimeDefinedParameter]::new(
'Add', [switch], $attributeCollection
)
$paramDictionary = [System.Management.Automation.RuntimeDefinedParameterDictionary]::new()
$paramDictionary.Add('Add', $dynParam1)
$parameterAttribute1 = [System.Management.Automation.ParameterAttribute]#{
ParameterSetName = "RemovingMembers"
Mandatory = $false
}
$attributeCollection1 = [System.Collections.ObjectModel.Collection[System.Attribute]]::new()
$attributeCollection1.Add($parameterAttribute1)
$dynParam11 = [System.Management.Automation.RuntimeDefinedParameter]::new(
'Remove', [switch], $attributeCollection1
)
$paramDictionary.Add('Remove', $dynParam11)
return $paramDictionary
}
}
Begin {
$ABool = {
'Add Block'
$Bool = Read-Host -Prompt 'Adding or Removing Member(s)'
if ($Bool.ToLower() -like 'a*') {
$true
}
else {
Break;
}
}
$RBool = {
'Remove Block'
$Bool = Read-Host -Prompt 'Adding or Removing Member(s)'
if ($Bool.ToLower() -like 'r*') {
$true
}
else {
Break;
}
}
if ($PSBoundParameters['Add'].IsPresent) { [bool]$Add = $true }
elseif ($PSBoundParameters['Remove'].IsPresent) { [bool]$Remove = $true }
elseif (-not$PSBoundParameters['Add'].IsPresent) { $Add = & $ABool }
elseif (-not$PSBoundParameters['Remove'].IsPresent) { $Remove = & $RBool }
}
Process {
if ($Add) {
"Add was selected"
}
if ($Remove) {
"Remove was selected"
}
}
}
I can run it several ways:
Test-Bool -Workflow spg -UserName a -Add - works
Test-Bool -Workflow spg -UserName a -Remove - works
Test-Bool -Workflow spg
Should ask to remove or add: Typing Add, works.
Typing Remove, does not work.
Which makes sense, because elseif (-not$PSBoundParameters['Add'].IsPresent) { $Add = & $ABool } is evaluated first and when asked, Remove is typed in which throws it into the else block making it Break/Exit.
QUESTION:
What can I change to make $Remove be evaluated to true and vise-versa when Add is typed (to make $Add True)?
I honestly confused myself so much that I just decided to post here instead of attempting to figure this out on my own.

Answer 1

Use Parameter Sets instead:
Function Test-Bool {
[CmdletBinding(DefaultParameterSetName = 'Undecided')]
Param (
# Input Parameters
[Parameter(Mandatory = $false,
HelpMessage='Enter. Workflow. Name.')]
[Alias('OMB','MailBox')]
[string]$Workflow,
[Parameter(Mandatory = $false)]
[Alias('EDIPI','DisplayName')]
[string[]]$UserName,
[Parameter(Mandatory = $true, ParameterSetName = 'Add')]
[switch]$Add,
[Parameter(Mandatory = $true, ParameterSetName = 'Remove')]
[switch]$Remove
)
begin {
$action = if($PSCmdlet.ParameterSetName -eq 'Undecided'){
$answer = Read-Host -Prompt 'Adding or Removing Member(s)?'
if($answer -like 'a*'){
'Add'
}
elseif($answer -like 'r*') {
'Remove'
}
else {
throw 'Invalid option provided'
}
}
else {
$PSCmdlet.ParameterSetName
}
# $action now contains either 'Add' or 'Remove'
$actionBlock = #{
'Add' = { <# code to add user to workflow #> }
'Remove' = { <# code to remove user from workflow #> }
}[$action]
}
process {
# if/else statements no longer needed, $actionBlock contains the correct scriptblock
. $actionBlock
}
}
If a user doesn't specify either switch, the parameter set name will be Undecided, and the user will be prompted in the begin block - otherwise we simply use the parameter set name associated with the specified switch.
Since the two switch parameters belong to separate parameter sets, the user can no longer pick both.