Module geojson::ser

Write your struct to GeoJSON using serde

To output your struct to GeoJSON, either as a String, bytes, or to a file, your type must implement or derive serde::Serialize:

#[derive(serde::Serialize)]
struct MyStruct {
    ...
}

Your type must have a field called geometry and it must be serialized_with serialize_geometry:

#[derive(serde::Serialize)]
struct MyStruct {
   #[serde(serialize_with = "geojson::ser::serialize_geometry")]
   geometry: geo_types::Point<f64>,
   ...
}

All fields in your struct other than geometry will be serialized as properties of the GeoJSON Feature.

Examples

use serde::Serialize;
use geojson::ser::serialize_geometry;

#[derive(Serialize)]
struct MyStruct {
    // Serialize as geojson, rather than using the type's default serialization
    #[serde(serialize_with = "serialize_geometry")]
    geometry: geo_types::Point<f64>,
    name: String,
    population: u64
}

let my_structs = vec![
    MyStruct {
        geometry: geo_types::Point::new(11.1, 22.2),
        name: "Downtown".to_string(),
        population: 123
    },
    MyStruct {
        geometry: geo_types::Point::new(33.3, 44.4),
        name: "Uptown".to_string(),
        population: 456
    }
];

let output_geojson = geojson::ser::to_feature_collection_string(&my_structs).unwrap();

let expected_geojson = serde_json::json!(
    {
        "type":"FeatureCollection",
        "features": [
            {
                "type": "Feature",
                "geometry": { "coordinates": [11.1,22.2], "type": "Point" },
                "properties": {
                    "name": "Downtown",
                    "population": 123
                }
            },
            {
                "type": "Feature",
                "geometry": { "coordinates": [33.3, 44.4], "type": "Point" },
                "properties": {
                    "name": "Uptown",
                    "population": 456
                }
            }
        ]
    }
);

Reading and Writing GeoJSON

This module is only concerned with Writing out GeoJSON. If you’d also like to reading GeoJSON, you’ll want to combine this with the functionality from the crate::de module:

#[derive(serde::Serialize, serde::Deserialize)]
struct MyStruct {
    // Serialize as geojson, rather than using the type's default serialization
    #[serde(serialize_with = "serialize_geometry", deserialize_with = "deserialize_geometry")]
    geometry: geo_types::Point<f64>,
    ...
}

Functions

• serialize_geometry
  serde::serialize_with helper to serialize a type like a geo_types, as a GeoJSON Geometry.
• to_feature_byte_vec
  Serialize a single data structure to a GeoJSON Feature byte vector.
• to_feature_collection_byte_vec
  Serialize elements to a GeoJSON FeatureCollection byte vector.
• to_feature_collection_string
  Serialize elements to a GeoJSON FeatureCollection string.
• to_feature_collection_writer
  Serialize elements as a GeoJSON FeatureCollection into the IO stream.
• to_feature_string
  Serialize a single data structure to a GeoJSON Feature string.
• to_feature_writer
  Serialize a single data structure as a GeoJSON Feature into the IO stream.