release_schedule/README.md

# Release Schedule

A small app using the Wikidata API to show upcoming movies.

You can try out the live web version at [daniel-michel.github.io/release_schedule](https://daniel-michel.github.io/release_schedule).

Android and Linux builds can be found in the latest [build run](https://github.com/daniel-michel/release_schedule/actions/workflows/build.yml).

Currently, only a simple list of upcoming movies is shown:

![](screenshots/movie_list.png)

The floating button at the bottom right can be used to load the upcoming movies and the button at the top right to clear the movies that where already loaded.


## Wikidata API

The Implementation can be found at [./lib/api/wikidata_movie_api.dart](./lib/api/wikidata_movie_api.dart).

To get information about the upcoming movies multiple APIs are used.

First the SPARQL API is used to retrieve upcoming movies using the endpoint "https://query.wikidata.org/sparql" with the following query:
```sql
SELECT
  ?movie
  (MIN(?releaseDate) as ?minReleaseDate)
WHERE {
  ?movie wdt:P31 wd:Q11424;         # Q11424 is the item for "film"
         wdt:P577 ?releaseDate.      # P577 is the "publication date" property
  FILTER (xsd:date(?releaseDate) >= xsd:date("$date"^^xsd:dateTime))
}
GROUP BY ?movie
ORDER BY ?minReleaseDate
LIMIT $limit
```
Where `$limit` is the maximum number of movies that are retrieved and `$date` the starting date from which movies are retrieved.
`$limit` is currently set to 100 and `$date` one week before the current one.
However, because there are multiple publication dates for most movies, the retrieved movies just need to have one publication date that is on or after `$date` for the movie to be included in the result. The `minReleaseDate` is not necessarily the release date displayed in the App, therefore some movies in the App might show up as having been released a long time ago.

To get additional information about the movies and all release dates (in case some are before `$date` and some after) the API endpoint "https://www.wikidata.org/w/api.php?action=wbgetentities" is used.