How to generate transparent preview of the document?

Question

Hi all,
I would like to generate trsansparent preview of an document in PNG file. Normal (not-transparent preview) I am doing by JavaScript like it is described below:
var myDocument = app.open(File(app.scriptArgs.getValue("documentPath")));
myDocument.exportFile(ExportFormat.jpg, File(app.scriptArgs.getValue("thumbnailPath")), PDFExportPreset.acrobatCompatibility);
myDocument.close(SaveOptions.no);
The result is normal JPG file. But I would like to get a transparent image. How can I do this?
Thank you for all information!

Answer 1

Hmm could you give any example of code? According to the scripting reference there is nothing like "ExportFormat.PNG_FORMAT" - I cannot even find this in Google. On official Adobe webpage in the scripting reference I can find:
Name Description Value
TAGGED_TEXT
Exports to a tagged text file with a TXT extension.
1416066168  =                 'Tgtx'
PDF_TYPE
Exports to PDF format.
1952403524  =                 't_PD'
EPS_TYPE
Exports to EPS format.
1952400720  =                 't_EP'
RTF
Exports to rich text format (RTF).
1381254688  =                 'RTF '
SVG
Exports to SVG format.
1398163232  =                 'SVG '
SVG_COMPRESSED
Exports to SVGZ format.
1398163267  =                 'SVGC'
TEXT_TYPE
Exports to text (TXT) format.
1952412773  =                 't_te'
XML
Exports the document's tagged content to XML.
1481460768  =                 'XML '
JPG
Exports to JPEG format.
1246775072  =                 'JPG '
INDESIGN_INTERCHANGE
Exports to InDesign Interchange (INX) format.
1229871136  =                 'INX '
INDESIGN_SNIPPET
Exports to InDesign Snippet (INDS) format.
1936617588  =                 'snpt'
INCOPY_CS_DOCUMENT
Exports to InCopy CS document (INCD) format.
1702126436  =                 'etcd'
INCOPY_DOCUMENT
Exports to InCopy document (INCX) format.
1702126456  =                 'etcx'
and this is all (http://www.indesignscriptingreference.com/CS3/JavaScript/ExportFormat-enum.htm). When I am trying to use the code on a group of objects, it is failing. The code:
var myDocument = app.documents.add();
myDocument.pages.item(0).place(File(app.scriptArgs.getValue("snippetPath")));
g = myDocument.pages.item(0).groups.add (myDocument.pages.item(0).allPageItems);
g.exportFile(ExportFormat.PNG_FORMAT, File(app.scriptArgs.getValue("pngThumbnailPath")), PDFExportPreset.acrobatCompatibility);
myDocument.close(SaveOptions.no);
And the error:
Error Number: 55
Error String: Object does not support the property or method 'PNG_FORMAT'
Line: 6
Source: g.exportFile(ExportFormat.PNG_FORMAT, File(app.scriptArgs.getValue("pngThumbnailPath")), PDFExportPreset.acrobatCompatibility);