PowerShell Requires Chilkat v11.5.0+

Box: Poll User Events and Save a Checkpoint

See more Box Examples

Poll the authenticated user event stream in bounded batches. The local JSON checkpoint keeps processed event IDs and the next stream position. This single-process demonstration logs events; a production worker should commit its business action, deduplication record, and cursor transactionally and prune old IDs.

See the Box API guide for setup and the complete workflow.

PowerShell

Add-Type -Path "C:\chilkat\ChilkatDotNet47-x64\ChilkatDotNet47.dll"

$success = $false

#  Requires Chilkat 11.5.0 or later and a previously unlocked Chilkat bundle.
#  See Global Unlock Sample.
#  Guide: Box API Guide.

$success = $false

#  Supply an unexpired token obtained with one of the Box authentication examples.
#  A token represents a particular user or service account. IDs must be accessible to it.
$curl = New-Object Chilkat.HttpCurl
$curl.SetVar("access_token","BOX_ACCESS_TOKEN")

$state = New-Object Chilkat.JsonObject
$files = New-Object Chilkat.FileAccess
$statePath = "qa_data/box_events_state.json"
if ($files.FileExists($statePath) -eq $true) {
    $success = $state.LoadFile($statePath)
    if ($success -ne $true) {
        $($state.LastErrorText)
        exit
    }

    if ($state.HasMember("position") -ne $true) {
        $("Invalid checkpoint: position missing.")
        exit
    }

}
else {
    #  "now" starts a new subscription. It deliberately skips historical events.
    $state.UpdateString("position","now")
}

$curl.SetVar("position",$state.StringOf("position"))
$page = New-Object Chilkat.JsonObject
$seenPath = New-Object Chilkat.StringBuilder

$batch = 0

$more = $true
while (($more -eq $true) -and ($batch -lt 20)) {
    $curl.ClearTargetOutput("*")
    $authorizedCommand1 = New-Object Chilkat.StringBuilder
    $authorizedCommand1.SetString("curl -X GET `"https://api.box.com/2.0/events?stream_type=all&stream_position={{position}}&limit=100`" -H `"Authorization: Bearer {{access_token}}`"")
    $headerReplacement1 = $authorizedCommand1.Replace("{{access_token}}",$curl.GetVar("access_token"))
    $success = $curl.DoYourThing($authorizedCommand1.GetAsString())
    if (($success -ne $true) -or ($curl.StatusCode -ne 200)) {
        $("Box request failed. HTTP status: " + $curl.StatusCode)
        $("Failure reason: " + $curl.FailReason)
        $($curl.ResponseBodyStr)
        exit
    }

    $success = $curl.GetResponseJson($page)
    if ($success -ne $true) {
        $($curl.LastErrorText)
        exit
    }

    $count = $page.SizeOfArray("entries")
    $i = 0
    while ($i -lt $count) {
        $page.I = $i
        $eventId = $page.StringOf("entries[i].event_id")
        if ($eventId -eq "") {
            $("Event without an event_id; checkpoint not advanced.")
            exit
        }

        $seenPath.Clear()
        $seenPath.Append("seen.")
        $seenPath.Append($eventId)
        if ($state.HasMember($seenPath.GetAsString()) -eq $false) {
            #  Replace this logging with your idempotent business operation.
            #  Record success only after that operation succeeds.
            $($eventId + " " + $page.StringOf("entries[i].event_type") + " " + $page.StringOf("entries[i].source.id"))
            $state.UpdateBool($seenPath.GetAsString(),$true)
        }

        $i = $i + 1
    }

    $nextPosition = $page.StringOf("next_stream_position")
    if ($nextPosition -eq "") {
        $("Missing next_stream_position; checkpoint not advanced.")
        exit
    }

    $more = ($count -gt 0) -and ($nextPosition -ne $curl.GetVar("position"))
    $state.UpdateString("position",$nextPosition)
    $success = $state.WriteFile($statePath)
    if ($success -ne $true) {
        $($state.LastErrorText)
        exit
    }

    $curl.SetVar("position",$nextPosition)
    $batch = $batch + 1
}

$("Checkpoint saved. Run again later to continue polling.")