trilium/src/public/app/widgets/containers/container.js

import BasicWidget from "../basic_widget.js";

export default class Container extends BasicWidget {
    doRender() {
        this.$widget = $(`<div>`);
        this.renderChildren();
    }

    renderChildren() {
        for (const widget of this.children) {
            try {
                this.$widget.append(widget.render());
            } catch (e) {
                widget.logRenderingError(e);
            }
        }
    }
}