functions/Get-EssbaseFile.ps1

<#
   .SYNOPSIS
      List all files from a specified application and database.
   .DESCRIPTION
      List all files from a specified application and database.
   .PARAMETER RestURL <string>
      The base URL for the REST API interface. Example: 'https://your.domain.com/essbase/rest/v1'
   .PARAMETER Application <string>
      String value of the Application name for which to get a list of files.
   .PARAMETER Database <string>
      String value of the Database name for which to get a list of files.
   .PARAMETER WebSession <WebRequestSession>
      A Web Request Session that contains authentication and header information for the connection.
   .PARAMETER Credentials <pscredential>
      PowerShell credentials that contain authentication information for the connection.
   .INPUTS
      None
   .OUTPUTS
      System.Object
   .EXAMPLE
      Get-EssbaseFile -RestURL 'https://your.domain.com/essbase/rest/v1' -Application 'Test1' -Database 'MyDB' -WebSession $MyWebsession
   .EXAMPLE
      Get-EssbaseFile -RestURL 'https://your.domain.com/essbase/rest/v1' -Application 'Test1' -Database 'MyDB'' -Credential $MyCredentials
   .NOTES
      Created by : Shayne Scovill
   .LINK
      https://github.com/Shayne55434/RESTBase
#>

function Get-EssbaseFile {
   [CmdletBinding()]
   param(
      [Parameter(Mandatory)]
      [ValidateNotNullOrEmpty()]
      [string]$RestURL,
      
      [Parameter(Mandatory)]
      [ValidateNotNullOrEmpty()]
      [string]$Application,
      
      [Parameter(Mandatory)]
      [ValidateNotNullOrEmpty()]
      [string]$Database,
      
      [Parameter(Mandatory, ParameterSetName='WebSession')]
      [ValidateNotNullOrEmpty()]
      [Microsoft.PowerShell.Commands.WebRequestSession]$WebSession,
      
      [Parameter(Mandatory, ParameterSetName='Credential')]
      [ValidateNotNullOrEmpty()]
      [pscredential]$Credential,
      
      [Parameter(Mandatory, ParameterSetName='Username')]
      [ValidateNotNullOrEmpty()]
      [string]$Username
   )
   
   # Decipher which authentication type is being used
   [hashtable]$htbAuthentication = @{}
   if ($null -ne $Credential) {
      $htbAuthentication.Add('Credential', $Credential)
      Write-Verbose 'Using provided credentials.'
   }
   elseif ($null -ne $WebSession)  {
      $htbAuthentication.Add('WebSession', $WebSession)
      Write-Verbose 'Using provided Web Session variable.'
   }
   else {
      [pscredential]$Credential = Get-Credential -Message 'Please enter your Essbase password' -UserName $Username
      $htbAuthentication.Add('Credential', $Credential)
      Write-Verbose 'Using provided username and password.'
   }
   
   [hashtable]$htbInvokeParameters = @{
      Method = 'Get'
      Uri = "$RestURL/files/applications/$($Application)/$($Database)"
      Headers = @{
         accept = 'Application/JSON'
      }
   } + $htbAuthentication
   
   try{
      Write-Verbose "Getting a list of files from '$Application.$Database'."
      [object]$objFiles = Invoke-RestMethod @htbInvokeParameters
   }
   catch {
      Write-Error "Failed to get a list of items. $($_)"
   }
   
   return $objFiles
}