A Sitecore PowerShell Extensions script for clearing and applying profiles to one or more items

Reset Profiles.ps1

$rootItem = Get-Item .

if ($rootItem.Appearance.ReadOnly) {
    Show-Alert "You cannot edit this item because it is protected."
    return
}

if (!$rootItem.Security.CanWrite([Sitecore.Context]::User)) {
    Show-Alert "You do not have write access to this item in order to perform this action."
    return
}

$settings = @{
    Title            = "Reset Profiles"
    Description      = "Clear and assign profiles for one or more items."
    Width            = "800"
    Height           = "500"
    OkButtonName     = "Proceed"
    CancelButtonName = "Abort"
    Parameters       =
    @{ Name = "root"; Title = "Root Item"; Value = $rootItem.Paths.ContentPath; Editor = "info" },
    @{ Name = "descendants"; Title = "<span style=""top: -4px;position: relative;"">Include all descendants of this item</span>"; Value = $false },
    @{ Name = "presets"; Title = "Assign new ""Profile Cards""<br /><span style=""font-weight:normal; font-style:italic; display: block;"">(Multiple Profile Cards under the same profile will be distributed equally)</span><br />"; Source = "DataSource=/sitecore/system/Marketing Control Panel/Profiles&DatabaseName=master&IncludeTemplatesForSelection=Profile Card"; Editor = "treelist" }
}

$result = Read-Variable @settings
if ($result -ne "ok") {
    return
}

if ($presets) {
    
    $confirmPresets = [string]::Join("<br />", $presets.Name)
}
else {
    $confirmPresets = "<span style=""color: red"">None (existing profiles will be cleared)</span>"
}

$rootItemPath = $rootItem.Paths.ContentPath
$descendantsWarning = if ($descendants) { " <b>and ALL descendant items</b>" } else { "" }
$intro = "<span style=""color: red"">Pre-existing profiles on the root item ($rootItemPath)$descendantsWarning will be removed and replaced with the Profile Cards defined below.</span>"

$settings = @{
    Title            = "Warning"
    Description      = "Please ensure that the information below is correct before proceeding."
    OkButtonName     = "Everything looks good, run it!"
    CancelButtonName = "Abort"
    Parameters       =
    @{ Name = "warning"; Title = ""; Value = $intro; Editor = "info" },
    @{ Name = "root"; Title = "Root Item"; Value = $rootItem.Paths.ContentPath; Editor = "info" },
    @{ Name = "descendants"; Title = "Include all descendants of this item"; Value = $descendants.ToString(); Editor = "info" },
    @{ Name = "presets"; Title = "Assign new ""Profile Cards""<br /><span style=""font-weight:normal; font-style:italic; display: block;"">(Multiple Profile Cards under the same profile will be distributed equally)</span>"; Value = $confirmPresets; Editor = "info" }
}

$confirm = Read-Variable @settings
if ($confirm -ne "ok") {
    return
}

$items = New-Object System.Collections.Generic.List[System.Object]

function Get-ItemsRecursive($item) {
    $items.Add($item)
    if ($descendants) {
        foreach ($child in $item.Children) {
            Get-ItemsRecursive $child
        }
    }
}

Get-ItemsRecursive $rootItem

foreach ($item in $items) {

    if (!$item.Appearance.ReadOnly -and $item.Security.CanWrite([Sitecore.Context]::User) -and $item.Visualization.Layout) {

        [Sitecore.Analytics.Data.TrackingField] $trackingField = $item.Fields["__tracking"]

        foreach ($contentProfile in $trackingField.Profiles) {

            $matches = $presets | Where-Object { [Sitecore.Analytics.Data.ProfileUtil]::GetProfileItem($_).ID -eq $contentProfile.ProfileID }
            if ($matches) {

                # Clear out existing presets
                if ($contentProfile.Presets) {
                    $contentProfile.Presets.Clear()
                }
                else {
                    $contentProfile.Presets = New-Object "System.Collections.Generic.Dictionary``2[System.String,float]"
                }

                # Assign new presets with equal weight
                $percentage = [math]::Round(100 / $matches.Count, 5)
                foreach ($match in $matches) {
                    $contentProfile.Presets.Add($match.Key, $percentage)
                }

                # Save value
                $contentProfile.SaveToField = $true
            }
            else {
                # Remove profile/presets/keys
                $contentProfile.SaveToField = $false
            }
        }

        # Recalculate keys
        $updatedTrackingField = New-Object Sitecore.Analytics.Data.TrackingField -ArgumentList $trackingField.InnerField, $trackingField.GetFieldValue()

        # Update field
        $item.Editing.BeginEdit()
        $item.Fields["__tracking"].Value = $updatedTrackingField.GetFieldValue()
        $item.Editing.EndEdit() | Out-Null

        Write-Host "Updated Item:" $item.Paths.ContentPath
    }
    else {
        Write-Host "Skipped Item:" $item.Paths.ContentPath
    }
}