# ExOwm
[](https://hex.pm/packages/ex_owm)
[](https://hexdocs.pm/ex_owm/)
[](https://github.com/kociamber/ex_owm/blob/master/LICENSE)
[](https://hex.pm/packages/ex_owm)
[](https://github.com/kociamber/ex_owm/commits/master)
**Fast [Open Weather Map](http://openweathermap.org/technology) API client for Elixir applications.**
## Installation
Add ExOwm as a dependency to your `mix.exs` file:
```elixir
defp deps() do
[
{:ex_owm, "~> 1.3.1"}
]
end
```
## Upgrade from 1.0.X
**Please re-factor** your configuration as the module naming (specifically the order) has slightly changed. Use the configuration below:
## Configuration
To use OWM APIs, you need to [register](https://home.openweathermap.org/users/sign_up) for an account (free plan is available) and obtain an API key. After obtaining the key, set the environment variable OWM_API_KEY to your API key.
If you are using this application as a dependency in your project, add the following configuration to your `config/config.exs` file:
```elixir
config :ex_owm, api_key: System.get_env("OWM_API_KEY")
```
..and you are ready to go!
## Basic Usage
ExOwm currently handles the following main OpenWeatherMap [APIs](http://openweathermap.org/api):
* [Current weather data](http://openweathermap.org/current)
* [One Call API](https://openweathermap.org/api/one-call-api)
* [One Call API History](https://openweathermap.org/api/one-call-api#history)
* [5 day / 3 hour forecast](http://openweathermap.org/forecast5)
* [1 - 16 day / daily forecast](http://openweathermap.org/forecast16)
Please note that with a standard (free) license/API key, you may be limited in the number of requests per minute and may not have access to the 1 - 16 day/daily forecast. Please refer to OpenWeatherMap [pricing plans](http://openweathermap.org/price) for more details..
There are three main public interface functions for each API, accepting the same set of two parameters: a list of location maps and a keyword list of options.
Sample API calls:
```elixir
ExOwm.get_current_weather([%{city: "Warsaw"}, %{city: "London", country_code: "uk"}], units: :metric, lang: :pl)
[{:ok, %{WARSAW_DATA}}, {:ok, %{LONDON_DATA}}]
ExOwm.get_five_day_forecast([%{city: "Warsaw"}, %{city: "London", country_code: "uk"}], units: :metric, lang: :pl)
[{:ok, %{WARSAW_DATA}}, {:ok, %{LONDON_DATA}}]
ExOwm.get_sixteen_day_forecast([%{city: "Warsaw"}, %{city: "unknown City Name", country_code: "uk"}], units: :metric, lang: :pl, cnt: 16)
[{:ok, %{WARSAW_DATA}}, {:error, :not_found, %{"cod" => "404", "message" => "city not found"}}]
yesterday = DateTime.utc_now() |> DateTime.add(24 * 60 * 60 * -1, :second) |> DateTime.to_unix()
ExOwm.get_historical_weather([%{lat: 52.374031, lon: 4.88969, dt: yesterday}])
[{:ok, %{CITY_DATA}}]
```
For more details, refer to the official [docs](https://hexdocs.pm/ex_owm/readme.html).
## Overview
ExOwm utilizes some cool features such as:
* concurrent API calls
* super fast generational caching
* access to **main** [OWM APIs](http://openweathermap.org/api)!
Each location entry in the list spawns a separate task (Elixir worker process) to check whether the request has been made within a specified time interval. If it has, the result is fetched from the cache. Otherwise, an API query is sent, the result is cached, and the data is returned.
## Running local tests
Since all the tests are based on OWM API calls, they are disabled by default. To enable them, please remove `:api_based_test` from the `test/test_helper.exs file`.
## To do
* Add remaining OWM APIs (including One Call API 3.0)
## License
This project is MIT licensed. Please see the [`LICENSE.md`](https://github.com/Kociamber/ex_owm/blob/master/LICENSE.md) file for more details.
