pipelining through multiple functions in powershell

Question

The user launchs a script called wrapper.ps1 It has

param(
  [string]$command,
  [string]$item=''
  etc
)

I then evaluate this with

switch -wildcard ($command) {
  "command1" {function1 $item;}
  "command2" {function2 $item;} 
  etc. 
 }

Then I have a function1 like:

function function1 {
   param([string] $itemname =''}
   #etc...then:
   $summary = @{blah1 = $blah1; blah2= $blah2; blah3= $blah3; }
   return $summary

$blah# are simple strings. The question is how can I pipeline into function1 via wrapper.ps1? I'd like to call this script like this:

wrapper.ps1 command1 filename |ft blah1,blah3

Answer 1

You choose to return a hashtable so you can exploit it from the pipeline

wrapper.ps1  "command1" "item" | select -ExpandProperty values

or

wrapper.ps1 "command1" "item" | % {foreach ($hash in $_.keys){write-host "the key is $hash the value is $($_[$hash])"}}