SharePoint CRUD Operations on ListItem PropertyBag

# Initialize the SharePoint PowerShell environment
Add-PSSnapIn "Microsoft.SharePoint.Powershell" -ErrorAction:SilentlyContinue

# Function to perform add , delete , view and update operation on list item properties
# Parameters :
# -- ItemBagKey : Name of property of list item
# -- Operation : Type of operation  "ADD" , "UPDATE" , "DELETE" , "VIEW"
# -- NewValue : Value for the item property 
# -- Item : List item to operate upon 

Function UpdateKey{

      param([string]$ItemBagKey,[string]$Operation,[string]$NewValue,[Microsoft.SharePoint.SPListItem]$item)

      if($Operation -eq "ADD") # If we are adding property to item.

      {

            if($item.Properties.ContainsKey($ItemBagKey))

            {

                  Write-Host "Key already found in item bag." -ForegroundColor Yellow;

                  $item.Properties[$ItemBagKey] = $NewValue;

                  $item.SystemUpdate($false);

                  Write-Host "Key update with new value : "  $NewValue - ForegroundColor Green;

            }

            else

            {

                  Write-Host "Key not found in item bag." -ForegroundColor Yellow;

                  $item.Properties.Add($ItemBagKey,$NewValue);

                  $item.SystemUpdate($false);

                  Write-Host "Key added with value : "  $NewValue -ForegroundColor Green;

            }

      }

      elseif($Operation -eq "DELETE") # If we are deleting property from item.

      {

            if($item.Properties.ContainsKey($ItemBagKey))

            {

                  $item.Properties.Remove($ItemBagKey);

                  $item.SystemUpdate($false);

                  Write-Host "Key removed from item bag : "  $ItemBagKey -ForegroundColor Green;

            }

            else

            {

                  Write-Host "Key not found in item bag to remove." -ForegroundColor Red;

            }

      }

      elseif($Operation -eq "UPDATE") # If we are updating property of item.

      {

            if($item.Properties.ContainsKey($ItemBagKey))

            {

                  $item.Properties[$ItemBagKey] = $NewValue;

                  $item.SystemUpdate($false);

                  Write-Host "Key updated with new value : "  $NewValue -ForegroundColor Green;

            }

            else

            {

                  Write-Host "Key not found in item bag." -ForegroundColor Red;

            }

      }

      elseif($Operation -eq "VIEW") # If we want to view value item property.

      {

            if($item.Properties.ContainsKey($ItemBagKey))

            {

                  Write-Host "Property value : "  $item.Properties[$ItemBagKey] -ForegroundColor Yellow;

            }

            else

            {

                  Write-Host "Key not found in item bag." -ForegroundColor Red;

            }

      }

}

try

{

     

      #Put your site URL in placeholder <siteurl> 

      $web = Get-SPWeb <siteurl>     

      #Put list name in placeholder <listname> 

      $list = $web.Lists["<listname>"] 

      #If the list is found
      if($list)

      {

  
  #Put list item id in placeholder <itemid> 
  $item = $list.GetItemById(<itemid> );

  #Put Item property key that you want to operate upon in placeholder               <propkey> 
  $_ItemBagKey = "<propkey>"


  #Replace placeholder <OP> with type of operation you want to perfrom it            could be one among four values ( ADD, UPDATE , DELETE , VIEW )
  $_Operation  = "<OP>"  # "ADD" # "UPDATE" # "DELETE" # "VIEW"

       #Replace placeholder <propvalue> with new value that you want to update          if you want to delete or view just leave the value blank.
       $_NewValue   = "<propvalue>"

  

 #call function to perform operation
 UpdateKey $_ItemBagKey $_Operation $_NewValue $item

 #Dispose web object to release resources.
 $web.Dispose()

}
else
{
   Write-Host "List not found." -ForegroundColor Red;
}

}

catch

{

   # Add your exception handling routine here to trap and handle the exception details.

}