Configuring RxDB for Nuxt+Electron using SQLITE3

RxDB is a tool for setting up a reactive database which in turn uses PouchDB, which in turn offers a variety of adapters that can build different types of databases with solutions like indexeddb and websql. It wasn’t altogether clear to me whether it would work nicely in an Electron app, and a nuxt.js driven one at that. Installation was a right nightmare.

To get setup you probably want to use sqlite / the websql adapter in pouchdb/RxDB. This involves configuring node-gyp and a bunch of dependencies. It won’t run properly out of the box until you tailor it to the version of electron you are running. To get sqlite3 running you will need a bunch of other dependencies installed as well, such as python 2.7. On Windows the most convenient way to do is to install windows-build-tools.

Here are some helpful tips if you have trouble installing windows build tools

If you get errors like “electron-v1.3-win32-x64\node_sqlite3.node module missing” you can try performing the manual steps outlined here and here. The important bit is that you need to tie your sqlite3 package to the specific version of electron that you have running in your project.

I also was getting webpack errors (unexpected character # at 1:0) relating to js files that open with a # hash/shebang directive. To fix that you can install the shebang loader and run it on the js files (like this) in question as a loader in your webpack configuration. In a nuxt project you configure your webpack config modifications in the nuxt.config.js file!

If you fail to get things running like I did for 3 days (until I got it working), there are alternatives like lowdb, nedb or realm but it really depends on what kind of setup you need in your project.

Update

So it turns out the hardest part of setting up RxDB with sqlite3 is due to webpack not working well with native add-ons. There are a whole slew of build/parsing errors you will encounter by the dependencies that are introduced via node-gyp, node-pre-gyp and sqlite3. The errors are very similar to ones mentioned in this webpack related thread. Some examples:

SyntaxError: Unexpected character '#' (1:0)

the request of a dependency is an expression

Module not found: Error: Cannot resolve module 'node-gyp'

node-pre-gyp/~/tar/tar.js
Module build failed: SyntaxError: Invalid number (108:10)

Workaround

Because nuxt.js uses a SSR approach you’re kind of stuck with webpack for all your components. However, RxDB can work just fine with sqlite3 (via the pouchdb-node-websql-adapter) on the client. This offers one way of working around webpack: just load up RxDB as a script asset on the client and access it inside a Vue instance. You can configure a header script in your nuxt.config.js file. You may want to set webSecurity to false to be able to load the script as a local file.