Use a parameter switch to change how a function behaves - function

Question

My main PowerShell code runs a function that logs to the Windows eventlog. If the level is error it uses a separate event ID which then our monitoring will pick up that exact ID and run an action. However, if I want to specify in the parameter of the main script (not the function) that this time running it use a different Event ID so it will NOT action monitoring, I don't know where to even start on that.
Is there a way to provide a switch parameter in the main script like $NoAlert which then changes the Event ID in the function?
The function of logging lives in a PowerShell module I created. I am importing the module at the beginning of the script and then calling the function during the main script body.
Here is the function:
function WriteLog-SRTProd {
Param(
[string]$logT,
[Parameter(Mandatory=$true)][string]$level,
[String]$LogFileDirT = "\\ServerA\Logs"
)
$RSLogfileT = (Get-ChildItem -Path $LogFileDirT |
sort LastWriteTime |
select -Last 1).Name
## make sure a level is correctly selected (mandatory)
if ("Error","Info","Warn" -NotContains $Level) {
throw "$($Environment) is not a valid name! Please use 'Error', 'Warn', or 'Info'"
}
if ($Level -eq "Info") {
Add-Content -Path "$LogFileDirT\$RSLogFileT" -Value "$(Get-Date -format MM-dd-yyyy::HH:mm:ss) INFO $logT"
Write-EventLog -LogName Application -Source TEST_MAINT -EntryType Information -EventId 100 -Message $logT -Category 0
}
if ($Level -eq "Warn") {
Add-Content -Path "$LogFileDirT\$RSLogFileT" -Value "$(Get-Date -format MM-dd-yyyy::HH:mm:ss) WARN $logT"
Write-EventLog -LogName Application -Source TEST_MAINT -EntryType Warning -EventId 200 -Message $logT -Category 0
}
if ($Level -eq "Error") {
Add-Content -Path "$LogFileDirT\$RSLogFileT" -Value "$(Get-Date -format MM-dd-yyyy::HH:mm:ss) ERROR $logT"
Write-EventLog -LogName Application -Source TEST_MAINT -EntryType Error -EventId 300 -Message $logT -Category 0
}
}
I'd like to run my script like this. When the $NoAlert is passed, it will send that switch to the function. Is this possible? Can I just add the switch in both places and use an if statement in the function for when the NoAlert switch is used?
PS C:\> .\Maintenance.ps1 -NoAlert
Param(
[switch]$NoAlert
)
WriteLog-SRTProd -level Error -logT "Custom Error Message"

Answer 1

I have created own function for logging and stored/installed as module, below is the part of my log module :
you can customize the write statements and add your code for event log. I have added 'NoAction' enum member as per your requirements.
I have used one Enum to separate the log levels
Enum Severity
{
Error = 3
Warning = 4
Informational = 6
Debug = 7
Verbose = 8
NoAction = 0 # AS PER YOUR REQUIREMENTS
}
function Write-Log()
{
[cmdletbinding()]
param
(
[Parameter(Position=0,mandatory=$true)]
[Severity] $LogLevel,
[Parameter(Position=1,mandatory=$true)]
[String] $Message
)
$TimeStamp = "$(Get-Date -format HH:mm:ss)" ;
Switch($LogLevel)
{
([Severity]::Error.ToString())
{
Write-Error "`t$TimeStamp : $Message`n" -ErrorAction Stop
break;
}
([Severity]::Warning.ToString())
{
Write-Warning "`t$TimeStamp : $Message`n" -WarningAction Continue
break;
}
([Severity]::Informational.ToString())
{
Write-Information "INROMATION:`t$TimeStamp : $Message`n" -InformationAction Continue
break;
}
([Severity]::Verbose.ToString())
{
Write-Verbose "`t$TimeStamp : $Message`n"
break;
}
([Severity]::NoAction.ToString())
{
Write-Verbose "`t$TimeStamp : $Message`n"
break;
}
} # END OF SWITCH
} # END OF FUNCTION
Sample Call :
Write-Log -LogLevel ([Severity]::Informational) -Message "test log message using info level"
Output :
INROMATION: 09:40:15 : test log message using info level

Answer 2

I have decided to just add a new parameter to both function and main script named $NoAlert. I have added an If($NoAlert){WriteLog-SRPProd -NoAlert} to the main script (messy, but its what I needed done). then in the Function, If($NoAlert){EventID 111}. so basically I am using the switch in the main script that then calls the NoAlert switch in the function. This is all done with a few added If/Else statements.
Hopefully that makes sense. Like I said its not the best answer, but I wanted to get it done and still provide an answer here in this post.