Purges a list from all its content

Purge-SPOList.ps1

<#
.SYNOPSIS
  Purge the content of a SharePoint list or library
.PARAMETER List
	The List Object to purge the content from
.PARAMETER BatchSize
  The BatchSize of the Query to the list
.PARAMETER Recycle
  If this switch is On, the Purge recycles the items instead of deleting them
.EXAMPLE
  Purge-SPOList -Web $web -Identity "Lists/Documents"
.EXAMPLE
  Purge-SPOList -Web $web -Identity db81c710-b4f3-4f39-849e-87f8ed8d7ec6
.EXAMPLE
  Purge-SPOList -Web $web -Identity "Lists/Documents" -Recycle
.EXAMPLE
  Purge-SPOList -Web $web -Identity "Lists/Documents" -BatchSize 10 -Recycle
#>
function Purge-SPOList()
{
  Param(
    [Parameter(Mandatory = $true, ValueFromPipeline = $true)]
    [Microsoft.SharePoint.Client.List]
    $List,
  
    [Parameter(Mandatory = $false)]
    [String]
    $BatchSize = 100,

    [Parameter(Mandatory = $false)]
    [switch]
    $Recycle
  )

  Process
  {
    #-----------------------------------------------------------------------
    # Ensure the ItemCount of the specified List
    #-----------------------------------------------------------------------
    if($List.ItemCount -eq $null)
    {
      Load-CSOMProperties -object $List -propertyNames @("ItemCount") -executeQuery
    }

    #-----------------------------------------------------------------------
    # Getting the start ItemCount
    #-----------------------------------------------------------------------
    $itemCount = $List.ItemCount

    #-----------------------------------------------------------------------
    # While there are results left to delete
    #-----------------------------------------------------------------------
    while($itemCount -gt 0)
    {
      [array]$items = Get-ListItems -List $List -BatchSize $BatchSize

      if ($items.Count -gt 0)
      {
        for ($i = $items.Count - 1; $i -ge 0; $i--)
        {
          #-----------------------------------------------------------------------
          # If the Recycle switch is on, Recycle the item to the Recycle Bin
          #-----------------------------------------------------------------------
          if($Recycle)
          {
            $items[$i].Recycle() | Out-Null
          }
          else 
          {
            $items[$i].DeleteObject()
          }
        } 
          
        #-----------------------------------------------------------------------
        # Executes the delete once every batch
        #-----------------------------------------------------------------------
        $list.Context.ExecuteQuery()
      }
      
      $itemCount = $itemCount - $items.Count
    }
  }
}

#region Private Methods
function Get-ListItems()
{
  Param(
    [Parameter(Mandatory=$true)]
    [Microsoft.SharePoint.Client.List]$List,

    [Parameter(Mandatory=$true)]
    [int]$BatchSize
  )
  
  Process 
  { 
    $query = [Microsoft.SharePoint.Client.CamlQuery]::CreateAllItemsQuery($BatchSize, "ID")
    $items = $List.GetItems($query)
    $List.Context.Load($items)
    $List.Context.ExecuteQuery()

    return $items
  }
}
#endregion

. .\Load-CSOMProperties.ps1