Method render

src/chart/chord/ChordView.ts:44–116

(seriesModel: ChordSeriesModel, ecModel: GlobalModel, api: ExtensionAPI)

    }

    render(seriesModel: ChordSeriesModel, ecModel: GlobalModel, api: ExtensionAPI) {
        const data = seriesModel.getData();
        const oldData = this._data;
        const group = this.group;

        const startAngle = -seriesModel.get('startAngle') * RADIAN;

        data.diff(oldData)
            .add((newIdx) => {
                /* Consider the case when there are only two nodes A and B,
                 * and there is a link between A and B.
                 * At first, they are both disselected from legend. And then
                 * when A is selected, A will go into `add` method. But since
                 * there are no edges to be displayed, A should not be added.
                 * So we should only add A when layout is defined.
                 */

                const layout = data.getItemLayout(newIdx);
                if (layout) {
                    const el = new ChordPiece(data, newIdx, startAngle);
                    getECData(el).dataIndex = newIdx;
                    group.add(el);
                }
            })

            .update((newIdx, oldIdx) => {
                let el = oldData.getItemGraphicEl(oldIdx) as ChordPiece;
                const layout = data.getItemLayout(newIdx);

                /* Consider the case when there are only two nodes A and B,
                 * and there is a link between A and B.
                 * and when A is disselected from legend, there should be
                 * nothing to display. But in the `data.diff` method, B will go
                 * into `update` method and having no layout.
                 * In this case, we need to remove B.
                 */
                if (!layout) {
                    el && graphic.removeElementWithFadeOut(el, seriesModel, oldIdx);
                    return;
                }

                if (!el) {
                    el = new ChordPiece(data, newIdx, startAngle);
                }
                else {
                    el.updateData(data, newIdx, startAngle);
                }
                group.add(el);
            })

            .remove(oldIdx => {
                const el = oldData.getItemGraphicEl(oldIdx) as ChordPiece;
                el && graphic.removeElementWithFadeOut(el, seriesModel, oldIdx);
            })

            .execute();

        if (!oldData) {