How to create a custom square in a-frame

Question

How can I create a custom square registering a new component in a-frame?

I am trying to update the example found here https://github.com/aframevr/aframe/blob/master/docs

Answer 1

This seems to work;

AFRAME.registerGeometry('example', {
      schema: {
        vertices: {
          default: ['-10 10 0', '-10 -10 0', '10 -10 0', '10 -10 0'],
        }
      },

      init: function (data) {
        var geometry = new THREE.Geometry();
        geometry.vertices = data.vertices.map(function (vertex) {
            var points = vertex.split(' ').map(function(x){return parseInt(x);});
            return new THREE.Vector3(points[0], points[1], points[2]);
        });
        geometry.computeBoundingBox();
        geometry.faces.push(new THREE.Face3(0, 1, 2));
        geometry.faces.push(new THREE.Face3(0, 2, 3));
        geometry.mergeVertices();
        geometry.computeFaceNormals();
        geometry.computeVertexNormals();
        this.geometry = geometry;
      }
    });

again followed by this in the html