Filter classes not exported

[coffex]

In a project I've been working on recently I've had need of the Geometry#apply function to convert the coordinates to and from WGS84, sinusoidal, and gnomonic projections.

I've had a lot of trouble getting this function to work correctly, but in the end I ended up using code similar to the following:

const jsts = require("jsts");

const translateFilter = {
  interfaces_: {
    indexOf: function (cls) {
      // the class name here is minified! Unable to trust that it remains stable between releases.
      console.log(cls.name);
      return true;
    }
  },
  filter: function (coord) {
    coord.x += 1;
    coord.y += 1;
  }
};

const coords = [new jsts.geom.Coordinate(0, 0), new jsts.geom.Coordinate(1, 1)];
const line = new jsts.geom.GeometryFactory().createLineString(coords);

console.log(line.getEnvelopeInternal());
line.apply(translateFilter);
line.geometryChanged();
console.log(line.getEnvelopeInternal());

This works ok if I want to just use CoordinateFilter, as its the first thing all the #apply implementations check for, but if I want to use a CoordinateSequenceFilter or GeometryFilter for example, I have to distinguish between them by their minified names.

It would be useful to have the *Filter classes exported in jsts.geom for this purpose, or to have a better interface for applying filters. If the *Filter classes do get exported, it would also be useful for their interfaces_ getter implementations to be filled out instead of being a blank array (see here). At that point the user could just subclass them and override #filter.

[bjornharrtell]

Interesting. Obviously the interfaces was never meant to be used other than internally, but I see your use case here.