This is example of generating, displaying and data change tracking of vector tiles (Mapbox Vector Tile format).

Prerequisites

• PostgreSQL with PostGIS
• Node.js

Database setup

Initialize database

psql -v ON_ERROR_STOP=ON -U postgres -f db/init.sql

Create tables, load data and create triggers

psql --single-transaction -v ON_ERROR_STOP=ON -U tileset -c '\i db/tables.sql' -c '\i db/data.sql' -c '\i db/triggers.sql'

Adjust connection

• Replace <YOUR_DB_HOST> placeholder in .env file with your own value.
• Replace <YOUR DB_PASSWORD> placeholder in .env file with your own value, if your database setting requires password authentication and change password:

psql -U tileset -c "ALTER ROLE tileset WITH PASSWORD '<YOUR DB_PASSWORD>'"

The data in the database is stored as follows:

Code setup

Install dependencies

npm ci

Build bundles

npm run build

Relationships between CTEs and style layers:

Live example

Run application server

node ./server/app-server.js

Run static server (in new terminal tab)

node ./server/static-server.js

Open in a browser

http://localhost:3000

The map should looks like this:

Full example: Topohub.kz

Changed tiles

Changes in the data are tracked. Based on a specific tileset and zoom range of a layer, the tiles impacted by these changes are calculated.

The tiles that affected by data changes: