About

This repository contains accompanying code for the article: Efficiently paging geospatial data with MongoDB - forwards and backwards!.

Setup

You will need Node.js and MongoDB ( version 3 or greater ) to run the examples.

After cloning the repo, execute:

yarn install

or if you don't use yarn:

npm install

in the top level directory.

Before running the examples, start MongoDB:

mongod --dbpath /some/path

This will start an instance which will accept connections at the default url: mongodb://localhost:27017. If you wish to modify the connection url used by all examples, edit the ./src/helpers/with_collection.coffee file.

Running examples

NOTE: running any of the examples will create a database named geo_paging_tutorial and a collection named locations ( the collection will be cleared if it exists ). You can change those in the same file as the connection url.

All files in the src folder ( apart from lib.coffee ) can be ran like so:

yarn coffee src/00_create_index.coffee

This will use the coffee binary from ./node_modules/.bin/. You can use npx instead of yarn to achieve the same result.

The functions exported in the src/lib.coffee file contain final implementation of the techniques described in the article. src/10_page_backwards_final.coffee demonstrates how to use them to page both forwards and backwards.

If you wish to compile the code do JavaScript, you can do something like:

yarn coffee -o lib -c src