Unable to append to file using FileWriter

[Darren]

We are building an iOS app that uses the FileWriter to write to a text file in temporary storage. The code to write to the file is taken from the File System sample app here: http://docs.telerik.com/platform/samples/sample-file/

Currently, the app is able to write to the file with the necessary data. However, when we restart the app and try to write to the file again it overwrites the previous file rather than appending. 

 

var fsHelper = new FileSystemHelper();
            fsHelper.writeLine(
                "offline.txt",
                "test",
                success,
                error
            );

            function success(msg) {
                console.log(msg);
            }

            function error(msg) {
                console.log(msg);
            }

 

The code that we are using for the FileSystemHelper can be found here: https://github.com/Icenium/sample-file/blob/master/sample-file/scripts/fileHelper.js

We are testing the code within the AppBuilder Device Simulator.

[Tsvetina]

Hello Darren,

To avoid overwriting the text, the sample uses the seek() method, which moves the write position to the end of the file. I tested this on a device and it works as expected—the new text gets appended to the old.

If you are restarting the simulator, or using the Reload button, note that the app directory is re-created, so you are actually not writing to the old file but creating a new one. I advise you to test your code on a physical device to confirm if it works as expected.

Regards,
Tsvetina
Telerik

 

 

[Darren]

Hi Tsvetina,

I had not tried testing the app on the device itself, so my problem must have been that it was recreating the app directory each time. Thank you!