internal/functions/Resolve-SchemaAttribute.ps1

function Resolve-SchemaAttribute
{
    <#
    .SYNOPSIS
        Combines configuration and adobject into an attributes hashtable.
     
    .DESCRIPTION
        Combines configuration and adobject into an attributes hashtable.
        This is a helper function that allows to simplify the code used to create and update schema attributes.
     
    .PARAMETER Configuration
        The configuration object containing the desired schema attribute name.
     
    .PARAMETER ADObject
        The ADObject - if present - containing the current schema attribute configuration.
        Specifying this will cause it to return a delta hashtable useful for updating attributes.
     
    .EXAMPLE
        PS C:\> Resolve-SchemaAttribute -Configuration $testItem.Configuration
 
        Returns the attributes hashtable for a new schema attribute.
         
    .EXAMPLE
        PS C:\> Resolve-SchemaAttribute -Configuration $testItem.Configuration -ADObject $testItem.ADObject
 
        Returns the attributes hashtable for attributes to update.
    #>

    [OutputType([hashtable])]
    [CmdletBinding()]
    param (
        $Configuration,
        
        $ADObject
    )
    
    process
    {
        #region Build out basic attribute hashtable
        $attributes = @{
            adminDisplayName = $Configuration.AdminDisplayName
            lDAPDisplayName  = $Configuration.LdapDisplayName
            attributeId         = $Configuration.OID
            oMSyntax         = $Configuration.OMSyntax
            attributeSyntax  = $Configuration.AttributeSyntax
            isSingleValued   = ($Configuration.SingleValued -as [bool])
            adminDescription = $Configuration.AdminDescription
            searchflags         = $Configuration.SearchFlags
            isMemberOfPartialAttributeSet = $Configuration.PartialAttributeSet
            showInAdvancedViewOnly = $Configuration.AdvancedView
        }
        #endregion Build out basic attribute hashtable
        
        #region If ADObject is present: Remove attributes that are already present
        $attributeNames = 'isSingleValued', 'searchflags', 'isMemberOfPartialAttributeSet', 'oMSyntax', 'attributeId', 'adminDescription', 'adminDisplayName', 'showInAdvancedViewOnly', 'lDAPDisplayName', 'attributeSyntax'
        
        if ($ADObject)
        {
            foreach ($attributeName in $attributeNames)
            {
                if ($ADobject.$attributeName -eq $attributes[$attributeName])
                {
                    $attributes.Remove($attributeName)
                }
            }
        }
        #endregion If ADObject is present: Remove attributes that are already present
        
        $attributes
    }
}