Example of application, which regularly get weather predictions from different external providers, and return to users average value.

You can try it here: http://178.62.245.179/

I use PHP 7.2, Postgres 11, Symfony 4.3, Docker for development environment, and DigitalOcean's droplet with ubuntu on production

We get data from our partners via API. And we've set a threshold of 1 minute to invalidate this data. It's possible to request our partners during each request to our API and keep a cache of the response in Memcache for 1 minute. But in this case, the first request, when we don have any cache, can take a lot of time (especially, if we will have more partners). That's why I decided to udpate a partner's data to our database by using a command and do it each minute by a cronjob.

• src/Integration/Prediction - Dummy integrations to weather predictions from partner for specific date
• src/DTO/PredictionData.php - Data Transfer Object (DTO) for keeping data from partner in original format
• src/DTO/Prediction.php - DTO for kepeng data from partner in common useful format
• src/Service/PredictionDataParser/PredictionDataParser.php - Service for parse PredictionData to array of Predicitons. It's easy to add parser for new format - you just need to implement SpecificPredictionDataParserInterface and register it in PredictionDataParser
• src/Service/ScaleConverter/ScaleConverter.php - service for convert different temperature scales to celsius and back. It's easy to add converter for new format - you just need to implement SpecificScaleConverterInterface and register it in ScaleConverter
• src/Entity/WeatherPrediction.php - Entity for saving predicitons to database. I keep temperature in single scale (celsius), because I think it makes code more easy and clear.
• src/Service/PredictionsActualizer.php - Service for updating predictions in database from provider's API
• src/Repository/WeatherPredictionRepository.php - AveragePredicitons caclulate on database side in celsius scale, you can see it in repository
• src/Controller/Api/Weather - Endpoint classes, like Controller, Validator, Mapper. Mapper can convert temperature to any available scale in ScaleConverter
• src/Command/WeatherPredictionsCollectCommand.php - command for updating predictions
• crontab - crontab for running command to update predicitons
• public/index.html - place for simple SPA

• Create tests
• Install nelmio-bundle and create auto-documentation
• Create simple frontend (public/index.html)

1. docker-compose up -d
2. docker-compose exec php-fpm composer install
3. docker-compose exec php-fpm cp /application/.env.dist /application/.env
4. docker-compose exec php-fpm php bin/console doctrine:migtrations:migrate
5. Check link https:/127.0.0.1:8080

Usage: php bin/console weather:predictions:collect [<upcomingDaysNumber>]

Arguments: upcomingDaysNumber For what number of upcoming days do you need to update a weather predictions? [default: 10]

GET /api/weather?city=Amsterdam&date=2019-11-29&scale=fahrenheit

Parameters:

city=Amsterdam // required
date=2019-11-29 // optional (default: current day) date for predicions in 'Y-m-d' format. It isn't be possible to search dates greater than the current day + 10 days.
scale=fahrenheit // optional (default: 'celsius'), scale like 'celsius', 'fahrenheit'

Example of response, if everything is fine: 200 OK

{
    predictions: [
        {
            city: "Amsterdam",
            predictionsDateTime: "2019-11-29 00:00:00",
            scale: "fahrenheit",
            temperature: 37,
            updatedAt: 1574271663
        },
        ...
    ]
}

Example of response, if request is incorrect: 400 Bad Request

{
    success: false,
    errors: [
        {
            propertyPath: "city",
            message: "Field can't be empty."
        },
        {
            propertyPath: "day",
            message: "Predictions are available only for today or upcoming 10 days"
        },
        {
            propertyPath: "scale",
            message: "Unsupported scale: Réaumur"
        }
    ]
}