Heisse Preise

A terrible grocery price search "app". Fetches data from big Austrian grocery chains daily and lets you search them. See https://heisse-preise.io.

The project consists of a trivial NodeJS Express server responsible for fetching the product data, massaging it, and serving it to the front end (see server.js). The front end is a least-effort vanilla HTML/JS search form (see sources in site/).

Contents:

• Requirements
• Running
  • Development
  • Production
  • Configuration
  • Via GitHub pages & GitHub workflows
  • Docker
• Raw Data
• Historical Data

Requirements

• Node.js

Running

Development

Install NodeJS, then run this in a shell of your choice.

git clone https://github.com/badlogic/heissepreise
cd heissepreise
npm install
npm run dev

The first time you run this, the data needs to be fetched from the stores. You should see log out put like this.

Fetching data for date: 2023-05-23
Fetched LIDL data, took 0.77065160000324 seconds
Fetched MPREIS data, took 13.822936070203781 seconds
Fetched SPAR data, took 17.865891209602356 seconds
Fetched BILLA data, took 52.95784649944306 seconds
Fetched HOFER data, took 64.83968291568756 seconds
Fetched DM data, took 438.77065160000324 seconds
Merged price history
App listening on port 3000

Once the app is listening per default on port 3000, open http://localhost:3000 in your browser.\

Subsequent starts will fetch the data asynchronously, so you can start working immediately.

Production

Install the dependencies as per above, then simply run:

npm run start

Frontend

To build the site/style.css file, make sure to run npm run build. This will create a css file based on the tailwind styles used. You can continue to write normal CSS in the site/tailwind.css if you want.

Configuration

You can pass the following options to the server.js script:

• -p, --port: the port to listen on, defaults to the PORT environment variable, if set, or 3000
• -l, --live-reload: whether to enable live reload, defaults to true when NODE_ENV is development. Cannot be used in production.

Via GitHub pages & GitHub workflows

Create a GitHub account and pick a username. Below, we assume your user name is hotprices123. Replace hotprices123 with your real username everywhere you see it below

1. Log in to your GitHub account.
2. Fork this repository and name the repository hotprices123.github.io.
3. In your forked repository:
   1. go to Settings > Pages, then under Branch select the main branch, and the docs/ directory as shown in this screenshot.
   2. go to Settings > Actions > General, then under Workflow permissions, select Read and write permissions as shown in this screenshot.
   3. go to the Actions tab, then select the Pages Update workflow in the list to the left, then click Enable workflow. Confirm that you know what you are doing.
4. Trigger the workflow once manually to build the initial site and data.
5. Once the workflow has finished, go to https:/hotprices123.github.io and enjoy your price comparisons.

The data will be automatically fetched once a day at 8am (no idea what timezone), and the site will be updated.

To get the latest code changes from this repository into your fork:

1. Go to https://github.com/hotprices123/hotprices123.github.io/compare/main...badlogic:heissepreise:main
2. Click on Create pull request
3. Enter a Title like "Updated from upstream", then click `Create pull request``
4. Click Merge pull request

Your site will now use the latest source code changes from this repository. It will be automatically updated and is usually live under https://hotprices123.github.io within 10-15 minutes.

Docker

The project has a somewhat peculiar Docker Compose setup in docker/ tailored to my infrastructure. You can entirely ignore it.

Raw Data

You can also get the raw data. The raw data is returned as a JSON array of items. An item has the following fields:

• store: (billa, spar, hofer, dm, lidl, mpreis)
• name: the product name.
• price: the current price in €.
• priceHistory: an array of { date: "yyyy-mm-dd", price: number } objects, sorted in descending order of date.
• unit: unit the product is sold at. May be undefined.
• quantity: quantity the product is sold at for the given price
• bio: whether this product is classified as organic/"Bio"

Historical Data

The live site at heisse-preise.io feature historical data from:

• Dossier
• @h43z, who runs preisinflation.online, another grocery price tracker.