Powershell: How to Validate Range between 1 to 15 and it should accepts pattern as 1,2,3,4,5 to 15 - regex

Question

I am a newbie in Power Shell Scripting.
I am trying to Achieve a functionality, that should accepts inputs from user in below criteria
Only Digits
Range Between 1 to 15
Should accept String of Array with comma Separated values ex: 1,2,3,4,14,15
Can Contain space in between commas
Values should not be duplicated
The Returned values must be Array
Till now, I have tried
Function Validate-Choice{
[cmdletbinding()]
Param(
[Parameter(Position=0,Mandatory=$True)]
[ValidateRange(1,15)]
[string[]]$Item
)
Process {$Item}
}
Validate-Choice 1,2,3,4,5,6,7,8,9,10,11,13 # Similar Way i want O/p
Out Put:
1
2
3
4
5
6
7
8
9
10
11
13
$ReadInput = Read-Host -prompt "Please Choose from the list [1/2/3/4/5/6/7/8/9/10/11/12/13/14] You can select multiple Values EX: 1, 2, 3 -- "
$userchoices = Validate-Choice -item $ReadInput
$userchoices
If read the same input from Host Getting Below Error
Validate-Choice : Cannot validate argument on parameter 'Item'. The argument cannot be validated because
its type "String" is not the same type (Int32) as the maximum and minimum limits of the parameter. Make sure the argument is of type Int32 and then try the command again. At line:10 char:21
+ Validate-Choice '1,2,3,4,5,6,7,8,9,10,11,13'
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidData: (:) [Validate-Choice], ParameterBindingValidationException
+ FullyQualifiedErrorId : ParameterArgumentValidationError,Validate-Choice
And also i am trying with different Regex patterns. But failing
Function Test-Something {
[cmdletbinding()]
Param(
[Parameter(Position=0,Mandatory=$True)]
[ValidatePattern('(?:\s*\d{1,15}[1-15]\s*(?:,|$))+$')]
[string[]]$Item
)
Process { $Item }
}
The above functions are partially resulting.
Can any one please help me here..!?

Answer 1

This would probably be easiest if you just changed the parameter type to [int[]] then your ValidateRange attribute does most of the work. It doesn't handle duplicates though. Turns out you can't use [ValidateScript()] as #PetSerAl points out. So that leaves checking the parameter the old fashioned way, in a begin block:
Function Test-Something {
[cmdletbinding()]
Param(
[Parameter(Position=0, Mandatory)]
[ValidateRange(1, 15)]
[int[]]$Item
)
Begin {
$ht = #{}
foreach ($i in $Item) {
if ($ht.ContainsKey("$i")) {
throw "Parameter Item must contain unique values - duplicate '$i'"
}
else {
$ht["$i"] = $i
}
}
}
Process {
[string]$Item
}
}
Test-Something (1,2,3,4,3)
Note that this won't work if you make the Item parameter accept pipeline input. In the pipeline input case, $Item will not be set in the begin block.

Answer 2

Naren_Ch
Your 1st usage of the advanced function (AF)
Validate-Choice 1,2,3,4,5,6,7,8,9,10,11,13 # Similar Way i want O/p
is correct - you are inputting data as expected by the AF.
Now, look at the example reading the input from the host:
$ReadInput = Read-Host -prompt "Please Choose from the list [1/2/3/4/5/6/7/8/9/10/11/12/13/14] You can select multiple Values EX: 1, 2, 3 -- "
When you do this, $ReadInput is a string, and in this case, it's a string full of commas!
Consequently, your data inputted to the AF will result in error caused by validation code, written by yourself.
To correct the situation, just do this:
$ReadInput = (Read-Host -prompt "Please Choose etc...") -split ','
$userchoices = Validate-Choice -item $ReadInput
You must remember that data read by Read-Host is a string (just 1 string).