public/Get-VSACustomField.ps1

function Get-VSACustomField
{
<#
.Synopsis
   Returns VSA custom fields.
.DESCRIPTION
   Returns existing VSA custom fields.
   Takes either persistent or non-persistent connection information.
.PARAMETER VSAConnection
    Specifies existing non-persistent VSAConnection.
.PARAMETER URISuffix
    Specifies URI suffix if it differs from the default.
.PARAMETER AgentId
    Specifies AgentId to get custom fields.
.PARAMETER Filter
    Specifies REST API Filter.
.PARAMETER Sort
    Specifies REST API Sorting.
    .PARAMETER Parallel
        Fetches the remaining pages of a large collection concurrently instead of one after another.
        Opt-in: without it, behaviour is unchanged. Results are identical either way (same records,
        merged in $skip order). Only engages once the collection is large enough to be worth it
        (see -ParallelThreshold).
    .PARAMETER ThrottleLimit
        Maximum number of concurrent requests when -Parallel is used (default 8). On shared SaaS you
        are one tenant among many, so a modest value is a good citizen; the engine also reduces
        concurrency automatically if the server returns HTTP 429, then recovers.
    .PARAMETER ParallelThreshold
        Minimum total record count before -Parallel actually engages. 0 (default) means automatic:
        two full throttle windows, i.e. 2 * ThrottleLimit * 100 records. Below that the sequential
        path is used, because it is faster than paying to set up extra connections..EXAMPLE
   Get-VSACustomField
.EXAMPLE
   Get-VSACustomField -VSAConnection $connection
.INPUTS
   Accepts piped non-persistent VSAConnection
.OUTPUTS
   Array of objects that represent existing VSA Custom Fields
#>

    [CmdletBinding(DefaultParameterSetName='All')]
    param (
        [parameter(Mandatory = $false,
            ValueFromPipelineByPropertyName = $true,
            ParameterSetName = 'All')]
        [parameter(Mandatory = $false,
            ValueFromPipelineByPropertyName = $true,
            ParameterSetName = 'ById')]
        [VSAConnection] $VSAConnection,

        [parameter(DontShow, Mandatory=$false,

            ParameterSetName = 'All')]
        [parameter(DontShow, Mandatory=$false,

            ParameterSetName = 'ById')]
        [ValidateNotNullOrEmpty()]
        [string] $URISuffix = 'api/v1.0/assetmgmt/assets/{0}/customfields',

        [parameter(Mandatory=$false,
            ValueFromPipelineByPropertyName=$true,
            ParameterSetName = 'ById')]
        [ValidateScript({
            if( (-not [string]::IsNullOrEmpty($_)) -and ($_ -notmatch "^\d+$") ) {
                throw "Non-numeric Id"
            }
            return $true
        })]
        [string] $AgentId,

        [Parameter(Mandatory = $false,
            ParameterSetName = 'All')]
        [ValidateNotNullOrEmpty()]
        [string] $Filter,

        [Parameter(Mandatory = $false,
            ParameterSetName = 'All')]
        [ValidateNotNullOrEmpty()]
        [string] $Sort,

        # Opt-in parallel paging for large collections (see Invoke-VSARestMethod). No effect on small
        # ones: below -ParallelThreshold the sequential path is used.
        [parameter(Mandatory = $false)]
        [switch] $Parallel,

        [parameter(Mandatory = $false)]
        [ValidateRange(1, 64)]
        [int] $ThrottleLimit = 8,

        [parameter(Mandatory = $false)]
        [ValidateRange(0, [int]::MaxValue)]
        [int] $ParallelThreshold = 0
    )
    process {

    $URISuffix = $($URISuffix -f $AgentId) -replace '//', '/' # URI suffix actualization

    [hashtable]$Params = @{
        VSAConnection = $VSAConnection
        URISuffix     = $URISuffix
        Filter        = $Filter
        Sort          = $Sort
    }

    #Remove empty keys
    foreach ( $key in @($Params.Keys)  ) {
        if ( -not $Params[$key]) { $Params.Remove($key) }
    }

    # Forward the opt-in parallel controls to the shared read path, which owns the paging engine.
    if ($Parallel) {
        $Params['Parallel']      = $true
        $Params['ThrottleLimit'] = $ThrottleLimit
        if ($ParallelThreshold -gt 0) { $Params['ParallelThreshold'] = $ParallelThreshold }
    }
    return Invoke-VSARestMethod @Params
    }
}
New-Alias -Name Get-VSACustomFields -Value Get-VSACustomField
Export-ModuleMember -Function Get-VSACustomField -Alias Get-VSACustomFields