Convert-WordDocument.ps1

  <#
    .Synopsis
    PowerShell script to convert Word documents

    .Description

    This script converts Word compatible documents to a selected format utilizing the Word SaveAs function. Each file is converted by a single dedicated Word COM instance.

    The script converts either all documents ina singlefolder of a matching an include filter or a single file.

    Currently supported target document types:
    - Default --> Word 2016
    - PDF
    - XPS
    - HTML

    Author: Thomas Stensitzki
    
    Version 1.1 2019-11-26
    
    .NOTES 
  
    Requirements 
    - Word 2016+ installed locally

    Revision History 
    -------------------------------------------------------------------------------- 
    1.0      Initial release
    1.1      Updated Word cleanup code

    .LINK
    http://scripts.granikos.eu

    .PARAMETER SourcePath
    Source path to a folder containing the documents to convert or full path to a single document

    .PARAMETER IncludeFilter
    File extension filter when converting all files  in a single folder. Default: *.doc

    .PARAMETER TargetFormat
    Word Save AS target format. Currently supported: Default, PDF, XPS, HTML

    .PARAMETER DeleteExistingFiles
    Switch to delete an exiting target file

    .EXAMPLE
    Convert all .doc files in E:\temp to Default

    .\Convert-WordDocument.ps1 -SourcePath E:\Temp -IncludeFilter *.doc 

    .EXAMPLE
    Convert all .doc files in E:\temp to XPS

    .\Convert-WordDocument.ps1 -SourcePath E:\Temp -IncludeFilter *.doc -TargetFormat XPS

    .EXAMPLE
    Convert a single document to Word default format

    .\Convert-WordDocument.ps1 -SourcePath E:\Temp\MyDocument.doc
  #>

  [CmdletBinding()]
  Param(
    [string]$SourcePath = '',
    [string]$IncludeFilter = '*.doc',
    [ValidateSet('Default','PDF','XPS','HTML')] # Only some of the supported file formats are currently tested
    [string]$TargetFormat = 'Default',
    [switch]$DeleteExistingFiles
  )

  $ERR_OK = 0
  $ERR_COMOBJECT = 1001 
  $ERR_SOURCEPATHMISSING = 1002
  $ERR_WORDSAVEAS = 1003

  # Define Word target document types
  # Source: https://msdn.microsoft.com/en-us/vba/word-vba/articles/wdsaveformat-enumeration-word  

  $wdFormat = @{
    'Document' = 0 # Microsoft Office Word 97 - 2003 binary file format
    'Template' = 1 # Word 97 - 2003 template format
    'Text' = 2 # Microsoft Windows text format
    'TextLineBreaks' = 3 # 
    'DOSText' = 4 # Microsoft DOS text format
    'DOSTextLineBreaks' = 5 # Microsoft DOS text with line breaks preserved
    'RTF' = 6 # Rich text format (RTF)
    'EncodedText' = 7 # Encoded text format
    'HTML' = 8 # Standard HTML format
    'WebArchive' = 9 # Web archive format
    'FilteredHtml' = 10 # Filtered HTML format
    'XML' = 11 # Extensible Markup Language (XML) format
    'XMLDocument' = 12 # XML document format
    'XMLDocumentMacroEnabled' = 13 # XML document format with macros enabled
    'XMLTemplate' = 14 # XML template format
    'XMLTemplateMacroEnabled' = 15 # XML template format with macros enabled
    'Default' = 16 # Word default document file format. For Word, this is the DOCX format
    'PDF' = 17 # PDF format
    'XPS' = 18 # XML template format
    'FlatXML' = 19 # Open XML file format saved as a single XML file
    'FlatXMLMacroEnabled' = 20 # Open XML file format with macros enabled saved as a single XML file
    'FlatXMLTemplate' = 21 # Open XML template format saved as a XML single file
    'FlatXMLTemplateMacroEnabled' = 22 # Open XML template format with macros enabled saved as a single XML file
    'OpenDocument' = 23 # OpenDocument Text format
    'StrictOpenXMLFormat' = 24 # Strict Open XML document format
  }

  $FileExtension = @{
    'Document' = '.doc'
    'Template' = '.dot'
    'RTF' = '.rtf'
    'HTML' = '.html'
    'Default' = '.docx'
    'PDF' = '.pdf'
    'XPS' = '.xps'
  }

  function Invoke-Word {
  [CmdletBinding()]
  Param(
    [string]$FileSourcePath = '',
    [string]$SourceFileExtension = '',
    [string]$TargetFileExtension = '',
    [int]$WdSaveFormat = 16, # Default docx
    [switch]$DeleteFile
  )

    if($FileSourcePath -ne '') {

      Write-Output ('Working on {0}' -f $FileSourcePath)
     
      # define variable for Word com object
      $WordApplication = $null

      # try to create a new instance of the COM object
      try{
        # New Word instance
        $WordApplication = New-Object -ComObject Word.Application
      }
      catch {
        Write-Error -Message 'Word COM object could not be loaded'
        Exit $ERR_COMOBJECT
      }

      # try to ope the document and save in new format
      try {

        $WordDocument = $WordApplication.Documents.Open($FileSourcePath)

        # Replace the source file extenson with the appropriate target file extension 
        $NewFilePath = ($FileSourcePath).Replace($SourceFileExtension, $TargetFileExtension)

        if((Test-Path -Path $NewFilePath) -and $DeleteFile) {
          
          # Delete existing file
          $null = Remove-Item -Path $NewFilePath -Force -Confirm:$false

        }

        # Now let's save the document
        $WordDocument.SaveAs([ref] $NewFilePath, [ref]$WdSaveFormat)

      }
      catch {

        # Ooops
        Write-Error -Message "Error saving document$($FileSourcePath): ´nException: $($_.Exception.Message)"
        Exit $ERR_WORDSAVEAS

      }
      finally{

        # Do some clean up
        # 2019-11-26 Updated
        $WordDocument.Close()
        $WordApplication.Quit()
        [Runtime.Interopservices.Marshal]::ReleaseComObject($WordApplication) | Out-Null

        if(Test-Path variable:global:WordApplication) {
          Remove-Variable -Name WordApplication -Scope Global 4>$Null
        }
        
        [GC]::Collect()
        [GC]::WaitForPendingFinalizers()
      }
    }
  }

  if($SourcePath -ne '') {

    # Check whether SourcePath is a single file or directory
    $IsFolder = $false
    try {
      $IsFolder = ((Get-Item -Path $SourcePath ) -is [System.IO.DirectoryInfo])
    }
    catch{}

    if($IsFolder) {

      # We need to iterate a source folder
      $SourceFiles = Get-ChildItem -Path $SourcePath -Include $IncludeFilter -Recurse

      Write-Verbose -Message ('{0} files found in {1}' -f ($SourceFiles | Measure-Object).Count, $SourcePath)

      # Let's work on all files
      foreach($File in $SourceFiles) {

        Invoke-Word -FileSourcePath $File.FullName -SourceFileExtension $File.Extension -TargetFileExtension $FileExtension.Item($TargetFormat) -WdSaveFormat $wdFormat.Item($TargetFormat)
        
      }
    }
    else{
      # It's just a single file

      $File = Get-Item -Path $SourcePath

        Invoke-Word -FileSourcePath $File.FullName -SourceFileExtension $File.Extension -TargetFileExtension $FileExtension.Item($TargetFormat) -WdSaveFormat $wdFormat.Item($TargetFormat)

    }
  }
  else {
    Write-Warning -Message 'No document source path has been provided'
    exit $ERR_SOURCEPATHMISSING
  }