//passing filename and fileURL as param

function OperationFile(filename,fileURL) {
    DownloadFile(filename,fileURL);
}

function OpenFile(filePath) {
        cordova.plugins.fileOpener2.open(
            filePath,
            'application/pdf',
            {
                error: function (e) {
                    alert("error open file :" +e);
                },
                success: function () {
                    alert("opening file :)))))");
                }
            }
        );
}

function DownloadFile(source,fileURL) {
        var fileTransfer = new FileTransfer();
        targetPath = GetFileDownloadPath();

	    var serverPath = fileURL;
        var uri = encodeURI(serverPath);

        fileTransfer.download(
            uri,
            targetPath,
            function (entry) {
                openFile(entry.toURL());
            },
            function (error) {
                fileTransferErrorToText(error);
            },
			// Optional parameter
            false,
			// Optional
            {
                headers: {
                    "Some header": "Titre PDF"
                }
            }
        );
}

function GetFileDownloadPath() {
        alert("entrer dans GetFileDownloadPath!");
        sessionStorage.platform = device.platform;
        if (sessionStorage.platform.toLowerCase() == "ios")
            return cordova.file.documentsDirectory + 'Download.pdf';
        else if (sessionStorage.platform.toLowerCase() == "android")
            return cordova.file.externalDataDirectory + 'Download.pdf';
        else
            return null;
}

function fileErrorToText(error) {
       var errorMessage = "";

       switch (error.code) {
           case FileError.SECURITY_ERR:
               errorMessage = "The app is not authorised to acces the local fileSystem.";
               break;
           default:
               errorMessage = "Undefined file error code: " + error.code;
               break;
       }

       return errorMessage;
}

function fileTransferErrorToText(error) {
       var errorMessage = "";

       switch (error.code) {
           case FileTransferError.CONNECTION_ERR:
               errorMessage = "Failed to download file because of an connection error";
               break;
           case FileTransferError.FILE_NOT_FOUND_ERR:
               errorMessage = "Failed to download file because the file did not exist";
               break;
           case FileTransferError.INVALID_URL_ERR:
               errorMessage = "Failed to download file because of an invalid URL";
               break;
           default:
               errorMessage = "Undefined file transfer error code: " + error.code;
               break;
       }

       return errorMessage;
  }