How to reuse/extend functions on Powershell? - powershell

Question

I'm trying to develop 2 functions with Powershell. The first, will check my database status (online/offline). The second function should loop on the first function until a certain state is achieve.
function Get-DBStatus
{
<# .. removed help section for brevity .. #>
[CmdletBinding()]
[OutputType([System.Object])]
param
(
[Parameter(Mandatory = $true)]
[String]$ServerName,
[Parameter(Mandatory = $true)]
[String]$ServerUser,
[Parameter(Mandatory = $true)]
[String]$ServerPassword,
[Parameter(Mandatory = $true)]
[String]$DatabaseName,
)
try
{
$params = #{ ... }
$dbStatus = Invoke-SqlConnection #params | Where-Object {$_.Name -match $AltDBName }
}
catch
{
Write-Error -Message ('An error has occured while ...')
}
if ([String]::IsNullOrEmpty($dbStatus) -eq $false)
{
$dbStatus
}
# <<< function Get-DbStatusOnlyIf
# <<< same parameters as the function above
# <<< get the desired status as a new parameter
# <<< loop the function above until the desired status is achieved or a timeout is reached
}
I'm new to Powershell and I think I shouldn't repeat myself rewriting the same parameters from the first function into the second one since they're dependent. However, I might be wrong, thus the question.
Thank you for your assistance!

Answer 1

You have to rewrite this parameters on your second function and pass them through or add another paramter to your first function that will do the looping. I would go with the second solution.
Try something like that
function Get-DBStatus {
<# .. removed help section for brevity .. #>
[CmdletBinding()]
[OutputType([System.Object])]
param
(
[Parameter(Mandatory = $true)]
[String]$ServerName,
[Parameter(Mandatory = $true)]
[String]$ServerUser,
[Parameter(Mandatory = $true)]
[String]$ServerPassword,
[Parameter(Mandatory = $true)]
[String]$DatabaseName,
$WaitForStatus, #or something like that
[int]$Timeout=10
)
do {
try {
#$params = #{ ... }
$dbStatus = Invoke-SqlConnection #params | Where-Object {$_.Name -match $AltDBName }
}
catch {
Write-Error -Message ('An error has occured while ...')
return
}
if ([String]::IsNullOrEmpty($dbStatus) -eq $false) {
if ($WaitForStatus){
if ($dbStatus -eq $WaitForStatus) {
$dbStatus
$EndLoop = $true
}
else {
Write-Host -NoNewline "." #only for test
Start-Sleep -Seconds 1
$Timeout -= 1
}
}
else{
$dbStatus
$EndLoop = $true
}
}
}
until ($EndLoop -or $Timeout -eq 0)
}
or with recursion
function Get-DBStatus {
<# .. removed help section for brevity .. #>
[CmdletBinding()]
[OutputType([System.Object])]
param
(
[Parameter(Mandatory = $true)]
[String]$ServerName,
[Parameter(Mandatory = $true)]
[String]$ServerUser,
[Parameter(Mandatory = $true)]
[String]$ServerPassword,
[Parameter(Mandatory = $true)]
[String]$DatabaseName,
$WaitForStatus, #or something like that
[int]$timeout = 3
)
if ($WaitForStatus) {
$start = Get-Date
while (((get-date) - $start).TotalSeconds -lt $timeout) {
$res = Get-DBStatus -ServerName $ServerName -ServerUser $ServerUser -ServerPassword $ServerPassword -DatabaseName $DatabaseName
if ($WaitForStatus -eq $res) {
return $res
}
Start-Sleep -Seconds 1
}
}
else {
try {
$params = #{ ... }
$dbStatus = Invoke-SqlConnection #params | Where-Object {$_.Name -match $AltDBName }
}
catch {
Write-Error -Message ('An error has occured while ...')
}
if ([String]::IsNullOrEmpty($dbStatus) -eq $false) {
$dbStatus
}
}
}