# Script to run custom Powershell commands on file changes

In writing Home Assistant components, I found it useful to restart a lightweight Home Assistant server on file changes to the Python component under development.

The following Powershell code will run the specified commands every time files change:


Function RunMyStuff {
Write-Output "Change detected"
docker restart hass-dev  ## add any PS command here
}

Function Watch {
$global:FileChanged =$false # dirty... any better suggestions?
$folder = "./custom_components/processor"$filter = "*.py"
$watcher = New-Object IO.FileSystemWatcher$folder, $filter -Property @{ IncludeSubdirectories =$false
EnableRaisingEvents = $true } Register-ObjectEvent$Watcher "Changed" -Action {$global:FileChanged =$true} > $null while ($true){
while ($global:FileChanged -eq$false){
# We need this to block the IO thread until there is something to run
# so the script doesn't finish. If we call the action directly from
# the event it won't be able to write to the console
Start-Sleep -Milliseconds 100
}

# a file has changed, run our stuff on the I/O thread so we can see the output
RunMyStuff

# reset and go again
$global:FileChanged =$false
}
}

RunMyStuff # run the action at the start so I can see the current output
Watch