This repository contains the source code for Tad, an open source (MIT Licensed) pivot table for SQL data sources, packaged both as a web application and a standalone desktop app.

Tad was initially released in 2017 as a standalone desktop application for viewing and exploring CSV files. This repository is a modular refactor of the original Tad source code, with several key improvements on the original code base:

• The repository is organized as a modular Lerna based monorepo, with (currently) 10 distinct npm modules (found in packages/).
• The code has been ported to TypeScript and the UI code has been updated to React Hooks.
• There is support for communicating with multiple database back ends for reltab (Tad's SQL generation and query evaluation layer), in addition to the original sqlite. Current backends (in varying degrees of completeness) include Snowflake, Google BigQuery, AWS Athena (Presto)
• Tad now has a simple web-based front-end (in addition to the Electron desktop application)
• The core Tad pivot table component now builds in its own module independent of any front end. This should allow embedding the Tad pivot table in other applications or contexts, such as Jupyter notebooks.

To build Tad, you should have node and npm(https://www.npmjs.com/get-npm) (included when you install Node.js) installed. The versions of these tools used for development are:

$ node --version
v12.13.1
$ npm --version
6.12.1  

Once you have Node installed, you should also install lerna globally using npm:

$ npm install --global lerna

Lerna supports a process called bootstrapping that links local packages together and installs any remaining dependencies. To the extent possible, lerna tries to hoist common dependencies needed by different packages in the monorepo. To bootstrap Tad correctly, run the following:

$ npm run bootstrap

This runs the standard lerna bootstrap command with a few extra arguments needed for how Tad's source is structured.

After bootstrapping, run the following script to try and build everything up to the reference web server:

$ ./build-web.sh

Set the environment variables $RELTAB_SNOWFLAKE_ACCOUNT, $RELTAB_SNOWFLAKE_USERNAME and $RELTAB_SNOWFLAKE_PASSWORD with a valid account name, username and password, respectively, for a Snowflake deployment.

If you have a Google BigQuery account, set the environment variable $GOOGLE_APPLICATION_CREDENTIALS to the path of a bigquery account credentials JSON file. If you do not have a Google BigQuery account, make a local edit packages/tadweb-server/src/server.ts and comment out the call await initBigquery(); at around line 145.

$ cd packages/tadweb-server
$ npm start

If all goes well, you will see something like:

db initialization complete
Listening on port  9000

open a web browser to localhost:9000 and all should be good.

A brief summary of the packages (modules) in this repository, found in the packages directory:

• reltab - The core abstraction used in Tad for programatically constructing and executing relational SQL queries. This also defines the driver interface for various specific database back-ends, and a small, transport-agnostic remoting layer to allow queries and results to be transmitted between the browser and a middle-tier.
  • reltab-sqlite -- SQLite driver for reltab
  • reltab-aws-athena - AWS Athena driver for reltab
  • reltab-bigquery - Google BigQuery driver for reltab
  • reltab-snowflake - Snowflake driver for reltab
• aggtree - A library built on top of reltab for creating pivot trees from relational queries.
• tadviewer - The core pivot table UI as a standalone, embeddable React component.
• tad-app - Standalone desktop app for Tad, built with Electron
• tadweb-app - A minimal web app built with tadviewer
• tadweb-server - A reference web server for serving the Tad web app and providing the reltab middle tier.

When iterating on the UI during development, after building everything I recommend keeping three windows open:

• In packages\tadviewer, running npm run watch
• In packages\tadweb-app, running npm run watch
• In tadweb-server, running npm start

With those running continuously, you should be able to just hit reload in your browser on localhost:9000 to pick up any code changes. Note that changes in below tadviewer (in reltab for example) will require you to explicitly compile in that directory (with npm run build).