Public/New-PlexPlaylist.ps1

function New-PlexPlaylist
{
    <#
        .SYNOPSIS
            Creates a new playlist.
        .DESCRIPTION
            Creates a new playlist.
        .PARAMETER Name
            Name of the playlist.
        .PARAMETER Type
            Type of playlist. Currently only 'video' is supported.
        .PARAMETER Id
            Id (ratingKey) of the Plex items to add. Can be a single item, comma separated list, or an array.
        .EXAMPLE
            New-PlexPlaylist -Name "My Playlist" -Type video -Id 123,456,789
        .EXAMPLE
            $Item = Find-PlexItem -Name "Some Movie"
            New-PlexPlaylist -Name "My Playlist" -Type video -Id $Item.ratingKey
    #>


    [CmdletBinding(SupportsShouldProcess)]
    param(
        [Parameter(Mandatory = $true)]
        [String]
        $Name,

        [Parameter(Mandatory = $true)]
        [ValidateSet('video')]
        [String]
        $Type,

        [Parameter(Mandatory = $true)]
        [String[]]
        $ItemId
    )

    #############################################################################
    #Region Import Plex Configuration
    if(!$script:PlexConfigData)
    {
        try
        {
            Import-PlexConfiguration -WhatIf:$False
        }
        catch
        {
            throw $_
        }
    }
    #EndRegion

    #############################################################################
    #Region Check if playlist already exists
    try
    {
        $Playlists = Get-PlexPlaylist
        if($Playlists.title -contains $Name)
        {
            throw "Playlist '$Name' already exists"
        }
    }
    catch
    {
        throw $_
    }
    #EndRegion

    #############################################################################
    #Region Get machine identifier
    Write-Verbose -Message "Function: $($MyInvocation.MyCommand): Getting list of Plex servers (to get machine identifier)"
    try
    {
        $CurrentPlexServer = Get-PlexServer -Name $DefaultPlexServer.PlexServer -ErrorAction Stop
        if(!$CurrentPlexServer)
        {
            throw "Could not find $CurrentPlexServer in $($Servers -join ', ')"
        }
    }
    catch
    {
        throw $_
    }
    #EndRegion

    #############################################################################
    #Region Construct Uri
    try
    {
        $Items = $ItemId -join ","
        $Params = [Ordered]@{
            title = $Name
            type  = $Type
            smart = 0
            uri   = "server://$($CurrentPlexServer.machineIdentifier)/com.plexapp.plugins.library/library/metadata/$Items"
        }
        $DataUri = Get-PlexAPIUri -RestEndpoint "playlists" -Params $Params
    }
    catch
    {
        throw $_
    }
    #EndRegion

    #############################################################################
    #Region Make request
    if($PSCmdlet.ShouldProcess($Item.title, "Add label '$Label'"))
    {
        Write-Verbose -Message "Adding label '$Label' to item '$($Item.title)'"
        try
        {
            $Data = Invoke-RestMethod -Uri $DataUri -Method POST
            return $Data.mediacontainer.metadata
        }
        catch
        {
            throw $_
        }
    }
    #EndRegion
}