Technical Information

This section contains details of how novelWriter stores and handles the project data.

How Data is Stored

All novelWriter files are written with utf-8 encoding. Since Python automatically converts Unix line endings to Windows line endings on Windows systems, novelWriter does not make any adaptations to the formatting on Windows systems. This is handled entirely by the Python standard library.

Main Project File

The project itself requires a dedicated folder for storing its files, where novelWriter will create its own “file system” where the folder and file hierarchy is described in a project XML file. This is the main project file in the project’s root folder with the name nwProject.nwx. This file also contains all the meta data required for the project, and a number of related project settings.

If this file is lost or corrupted, the structure of the project is lost. It is important to keep this file backed up, either through the built-in backup tool, or your own backup solution.

Note

The novelWriter project folder is structured so that it can easily be added to a version control system like git. If so, you may want to add a .gitignore file to exclude files with the extensions .json as JSON files are used to cache the index and various run-time settings.

The project XML file is indent-formatted, suitable for diff tools and version control, although a timesetamp is set in the meta section on line 2 each time the file is saved.

Project Documents

The project documents are saved in a folder in the main project folder named content. Each document has a file handle taken from the first 13 characters of a SHA256 hash of the system time when the file was first created. The documents are saved with a filename assembled from this hash and the file extension .nwd. If you wish to find the physical location of a file in the project, you can either look it up in the project XML file, or select Document ‣ Show File Details in the menu when having the document open.

The reason for this cryptic file naming is to avoid issues with file naming conventions and restrictions on different operating systems, and also to have a file name that does not depend on what the user names the files, or changes it to. The file meta data in the tree view, except the file label, is only saved in the project XML file.

Each document file contains a plain text version of the text from the editor. The file can in principle be edited in any text editor, and is suitable for diffing and version control if so desired. Just make sure the file remains in utf-8 encoding, otherwise unicode chatracters may become mangled when opened in novelWriter again.

The first line of the file contains some meta data starting with the characters “%%~”. This line is mainly there to restore some information if it is lost from the project file, and the information may be helpful if you do open the file in an external editor as it contains the file label as the last entry. The line can be deleted without any consequences to the rest of the content of the file, and will be added back next time the file is saved in novelWriter.

The File Saving Process

When saving the project file, or any of the documents, the data is first saved to a temporary file. If successful, the old data file is removed, and the temporary file becomes the new file. This ensures that the previously saved data is only replaced when the new data has been successfully saved. For the project XML file, a .bak file is kept which will always contain the previous version of the file, although when auto-save is enabled, they may have the same content.