Transform GeoJSON object to a realm object

[tdangexo]

Problem

I am working with GeoJSON data, here is an example:

"outline": { "type": "FeatureCollection", "features": [ { "type": "Feature", "geometry": { "type": "Polygon", "coordinates": [ [ [ 2.6581091091385147, 49.44587585244173 ], [ 2.6632589504471085, 49.4464059894905 ], [ 2.6648897335281636, 49.445317807250234 ], [ 2.6633018657913468, 49.443280888399926 ], [ 2.6581091091385147, 49.44587585244173 ] ] ] }, "properties": { "name": "An example" } } ] }

I want to save this data as a realm object of type Outline. I have tried to create an embedded model, i.e, Geometry > Feature > Outline, but the validation of realm schema failed when it came to "coordinates". It seems that realm does not support schema property of array of array of array.

Solution

Are there any alternatives to deal with GeoJSON data?

How important is this improvement for you?

I'd like to see it, but have a workaround

[fronck]

@tdangexo Thanks for the report. Can you share the Realm schema(s) you're working with?

[tdangexo]

Hello @fronck, here are my schemas:

User

static schema = {

    name: 'User',
    primaryKey: 'id',
    properties: {
      id: 'int',
      email: 'string',
      first_name: {type: 'string?', default: ''},
      last_name: {type: 'string?', default: ''},
      company_name: {type: 'string?', default: ''},
    },
  };

Farm

 static schema = {
    name: 'Farm',
    primaryKey: 'id',
    properties: {
      id:'int',
      name:'string',
      user:'User',
      address:'string',
      technical_contact:'string'
    },
  };

Outline

 static schema = {
    name: 'Outline',
    properties: {
      type:'FeatureCollection["type"]',
      features:'FeatureCollection["features"]'
    },
  };

As I mentionned above, Outline has specific properties since the data is of type GeoJSON. Here, FeatureCollection is a specific type/interface imported from geojson.

[kneth]

I can see the value in adding some utility functions to make it easier to work with GeoJSON but currently we don't have it on the agenda.

If type and features in Outline can be different kind of objects, mixed might be a good Realm type for it.

[ianpward]

@tdangexo Product for Realm & Device Sync here. I am interested in building this feature - I'd love to pick your bring on your use case if you're keen. If you could drop me a line at [email protected] and we can set up a time to chat.

[kneth]

For people interested in geospatial objects and queries, it might be interesting to follow https://github.com/realm/realm-core/pull/6352

[kneth]

v12.0.0-rc.0 contains geospatial queries and guidelines on how to transform data will be published.