83c521915c
We want to know how many phones are in a user-supplied polygon, so we can show the impact of a broadcast, in the same way that we do when users pick areas from our library. We already know how many phones are in each electoral ward. But there are challenges with an arbitrary polygon: - where it does overlap a ward, the overlap could be partial - it could overlap more than one ward - finding out which wards it overlaps by brute force (looping through all the wards and seeing which ones intersect with our polygon) would be way to slow to do in real time Instead we can use a data structure called an R-tree[1] to build an index which provides a much, much faster way of looking up which polygons overlap another. We can build this tree in advance and save it somewhere, which means there’s a lot of computation we don’t need to do in real time. The R-tree returns a set of objects (ward IDs) which we can go and look up in our library of electoral wards. These wards will be the ones that might have some overlap with our custom polygon. Once we have this small set of wards which might overlap our ward, we can look at the size of the area of overlap (relative to the size of the whole ward) and multiply that by the known count of phones in that ward to get an approximation of the count of phones in the overlap area. Summing these approximations give an estimate for the whole area of the custom polygon. 1. https://en.wikipedia.org/wiki/R-tree
notifications-admin
GOV.UK Notify admin application - https://www.notifications.service.gov.uk/
- Register and manage users
- Create and manage services
- Send batch emails and SMS by uploading a CSV
- Show history of notifications
Setting up
Python version
At the moment we run Python 3.6 in production.
NPM packages
brew install node
NPM is Node's package management tool. n is a tool for managing different versions of Node. The following installs n and uses the long term support (LTS) version of Node.
npm install -g n
n lts
environment.sh
In the root directory of the application, run:
echo "
export NOTIFY_ENVIRONMENT='development'
export FLASK_APP=application.py
export FLASK_ENV=development
export WERKZEUG_DEBUG_PIN=off
"> environment.sh
AWS credentials
To run parts of the app, such as uploading letters, you will need appropriate AWS credentials. See the Wiki for more details.
To run the application
# install dependencies, etc.
make bootstrap
# run the web app
make run-flask
Then visit localhost:6012.
To test the application
# install dependencies, etc.
make bootstrap
make test
Common tasks
Updating application dependencies
requirements.txt is generated from the requirements.in in order to pin versions of all nested dependencies. If requirements.in has been changed, run make freeze-requirements to regenerate it.
Automatically rebuild the frontend assets
If you want the front end assets to re-compile on changes, leave this running in a separate terminal from the app
npm run watch