gdocs_and_gdrive

// concatenate google docs. Takes an array of doc Ids and appends all docs to the first in the array
function mergeGoogleDocs(docIdsList) {
    var baseDoc = DocumentApp.openById(docIdsList[0]);

    var body = baseDoc.getActiveSection();

    for (var i = 1; i < docIdsList.length; ++i) {
        var otherBody = DocumentApp.openById(docIdsList[i]).getActiveSection();
        var totalElements = otherBody.getNumChildren();
        for (var j = 0; j < totalElements; ++j) {
            var element = otherBody.getChild(j).copy();
            var type = element.getType();
            if (type == DocumentApp.ElementType.PARAGRAPH)
                body.appendParagraph(element);
            else if (type == DocumentApp.ElementType.TABLE)
                body.appendTable(element);
            else if (type == DocumentApp.ElementType.LIST_ITEM)
                body.appendListItem(element);
            else
                throw new Error("Unknown element type: " + type);
        }
    }
}

// generate PDFs out of every file/GDoc in inFolder and put into outFolder if given, otherwise into source folder
function generatePdfs(inFolderId, outFolderId) {
    var infolder = DriveApp.getFolderById(inFolderId);
    var fileList = infolder.getFiles();
    var outfolder;

    if (outFolderId) {
        outfolder = DriveApp.getFolderById(outFolderId);
    } else {
        outfolder = infolder;
    }

    while (fileList.hasNext()) {
        var file = fileList.next();
        var pdfFile = DriveApp.createFile(file.getAs('application/pdf'));
        outfolder.addFile(pdfFile);
    }
}


// copying files on google drive... this one does not work on team drives, there is a second version below that does.
// use our own function to make file copies, as apps script solution is utter sh**... (1.6s for one file!!!)
function copyFile(originFileId, copyTitle, targetFolderId) {
    var response = Drive.Files.copy({
            "title": copyTitle,
            "parents": [
                {
                    "kind": "drive#fileLink",
                    "id": targetFolderId
                }
            ],
            "mimeType": "application/vnd.google-apps.document"
        }, originFileId
    );
    return response; // get fileId of new file and other metadata from response body
}

// teamdrive version
function copyFile(originFileId, copyTitle, targetFolderId) {
  var response = Drive.Files.copy({
    "title": copyTitle,
    "parents": [
      {
        "kind": "drive#fileLink",
        "id": targetFolderId
      }
    ],
    "mimeType": "application/vnd.google-apps.document"
  }, originFileId, {"supportsTeamDrives": true}
 );
  return response; // get fileId of new file and other metadata from response body
}

// generalized version for both normal gdrive and teamdrive
// defaults to normal gdrive, pass bTeam as true for teamdrive support
function copyFile(originFileId, copyTitle, targetFolderId, bTeam = false) {
  var response = Drive.Files.copy({
    "title": copyTitle,
    "parents": [
      {
        "kind": "drive#fileLink",
        "id": targetFolderId
      }
    ],
    "mimeType": "application/vnd.google-apps.document"
  }, originFileId, {"supportsTeamDrives": bTeam}
 );
  return response; // get fileId of new file and other metadata from response body
}