How do you modify this script to run TinyPNG on opened files instead of having to use the open dialog to select a file?

Question

I'm trying to modify this script to compress and then close all the opened files with the TinyPNG Photoshop plugin as opposed to having to choose one file at a time in an open dialog box. They do offer another script that allows you to compress a whole folder. However, I find myself needing to compress 10 out 50 images in a folder so I'd rather just be able to select those 10 or to open those 10 and run the script on all open files.

I've tried replacing

compressFile(File.openDialog("Choose a PNG or JPEG file to compress")

with

compressFile(app.activeDocument)

in an attempt to have the script just compress the current document.

Instead of using the active document it simply skips to the catch(error).

try {
    // Compress Active File
    compressFile(File.openDialog("Choose a PNG or JPEG file to compress"));
} catch(error) {
    alert("No JPEG or PNG file selected or compression error.");
}

Answer 1

compressFile() requires a File object while activeDocument is a document object.

For opened documents you'll want a loop through the documents:

for (var i = documents.length - 1; i >= 0; i--) {
    activeDocument = documents[i];
    compressFile()
}

and in compressFile() you should get rid opener part (because all the documents are already opened) but you'll need to replace a file with actual document path:

    // Compress the document
    var tinify = new ActionDescriptor();
    tinify.putPath(charIDToTypeID("In  "), new File(activeDocument.path + "/" + activeDocument.name)); /* Overwrite original! */
    tinify.putUnitDouble(charIDToTypeID("Scl "), charIDToTypeID("#Prc"), percentage);

For a files dialogue you can simply modify the last bit of Compress File.jsx:

//dialogue to select multiple files:
var startFolder = Folder.myDocuments,
    myFiles = startFolder.openDlg(void(0), void(0), true);

if (myFiles != null) //if the dialogue wasn't cancelled
{
    //launch compressFile for every selected file
    for (var i = myFiles.length - 1; i >= 0; i--)
    {
        compressFile(myFiles[i])
    }
}