Can't pass the value to the function

Question

I am trying to make a condition that if the value in the column is equal to the new column that I will be making is post the value from my else. But my function can't get the values from my data. Any advice?

function MainGroupChoice{        
    param (
        [Parameter(ValuefromPipeline = $true)][String] $value1,
        [Parameter(ValuefromPipeline = $true)][String] $value2,
        [Parameter(ValuefromPipeline = $true)][String] $choice1,
        [Parameter(ValuefromPipeline = $true)][String] $choice2
    )    

    if ($value1 -eq $value2) {
        return
        Add-Member -NotePropertyName MainGroup -NotePropertyValue $choice1 -PassThru  -Force
    }
    else {
        return
        Add-Member -NotePropertyName MainGroup -NotePropertyValue $choice2 -PassThru  -Force
    }
}



$table2 = $NestedGroupUsers | MainGroupChoice -choice1 $ADgroupname.name -choice2 $groupNestedName -value1 $table2.ParentGroup -value2 $nestedmember.distinguishedName

I got this error

The input object cannot
     | be bound to any
     | parameters for the
     | command either because
     | the command does not
     | take pipeline input or
     | the input and its
     | properties do not match
     | any of the parameters
     | that take pipeline
     | input.

Answer 1

I've answered your question below, but I feel obligated to tell you that this one-liner can likely accomplish the same as all the code below:

$nestedGroups |Select Value*,@{Name='MainGroup';Expression={if($_.value1 -eq $_.value2){$_.choice1}else{$_.choice2}}}

---

It looks like you'll want to:

1. Declare a parameter to receive the whole input object (so you can modify and/or return it later), and then
2. Mark the remaining parameters ValuefromPipelineByPropertyName (instead of ValuefromPipeline), and finally
3. Move the code into an explicit process {} block - this will ensure it's executed once for each input object bound via the pipeline

function MainGroupChoice {
    param (
        [Parameter(ValueFromPipeline)]$InputObject,
        [Parameter(ValuefromPipelineByPropertyName = $true)][String] $Value1,
        [Parameter(ValuefromPipelineByPropertyName = $true)][String] $Value2,
        [Parameter(ValuefromPipelineByPropertyName = $true)][String] $Choice1,
        [Parameter(ValuefromPipelineByPropertyName = $true)][String] $Choice2
    )    

    process {
        if ($value1 -eq $value2) {
            return $InputObject |Add-Member -NotePropertyName MainGroup -NotePropertyValue $choice1 -PassThru  -Force
        }
        else {
            return $InputObject |Add-Member -NotePropertyName MainGroup -NotePropertyValue $choice2 -PassThru  -Force
        }
    }

}

Testing with some mock input:

@(
  [pscustomobject]@{
    Value1 = 123
    Value2 = 123
    Choice1 = "Pick me!"
    Choice2 = "Not me..."
  }
  [pscustomobject]@{
    Value1 = 123
    Value2 = 456
    Choice1 = "Not me..."
    Choice2 = "Pick me!"
  }
) |MainGroupChoice |Select Value*,MainGroup

... and we should expect output like:

Value1 Value2 MainGroup
------ ------ ---------
   123    123 Pick me!
   123    456 Pick me!