firestore_helpers library

Classes

Area
Defines the search area by a circle center / radius Based on the limitations of FireStore we can only search in rectangles which means that from this definition a final search square is calculated that contains the circle
GeoBoundingBox
Defines the boundingbox for the query based on its south-west and north-east corners
OrderConstraint
Used by buildQuery to define how the results should be ordered. The fields corespond to the possisble parameters of Firestore`s oderby() method.
QueryConstraint
Used by buildQuery to define a list of constraints. Important besides the field property not more than one of the others can ne !=null. They corespond to the possisble parameters of Firestore`s where() method.

Functions

boundingBoxCoordinates(Area area) GeoBoundingBox
Calculates the SW and NE corners of a bounding box around a center point for a given radius; area with the center given as .latitude and .longitude and the radius of the box (in kilometers)
buildQuery({CollectionReference collection, List<QueryConstraint> constraints, List<OrderConstraint> orderBy }) → Query
Builds a query dynamically based on a list of QueryConstraint and orders the result based on a list of OrderConstraint. collection : the source collection for the new query constraints : a list of constraints that should be applied to the collection. orderBy : a list of order constraints that should be applied to the collection after the filtering by constraints was done. Important all limitation of FireStore apply for this method two on how you can query fields in collections and order them.
degreesToRadians(double degrees) → double
distance(GeoPoint location1, GeoPoint location2) → double
Calculates the distance, in kilometers, between two locations, via the Haversine formula. Note that this is approximate due to the fact that the Earth's radius varies between 6356.752 km and 6378.137 km. location1 The first location given location2 The second location given sreturn the distance, in kilometers, between the two locations.
getData<T>(Query query, DocumentMapper<T> mapper) → Stream<List<T>>
Convenience Method to access the data of a Query as a stream while applying a mapping function on each document qery : the data source mapper : mapping function that gets applied to every document in the query.
getLocationsConstraint(String fieldName, Area area) → List<QueryConstraint>
Creates the necessary constraints to query for items in a FireStore collection that are inside a specific range from a center point fieldName : the name of the field in FireStore where the location of the items is stored area : Area within that the returned items should be
metersToLongitudeDegrees(double distance, double latitude) → double
Calculates the number of degrees a given distance is at a given latitude. distance The distance to convert. latitude The latitude at which to calculate. returns the number of degrees the distance corresponds to.
wrapLongitude(double longitude) → double
Wraps the longitude to -180,180. [...]

Typedefs

DocumentMapper<T>(DocumentSnapshot document) → T