Listbox Renderer

From Documentation

Here we describe how to implement a custom renderer for a listbox (ListitemRenderer). For the concepts about component, model and renderer, please refer to the Model-driven Display section.

When a listbox (Listbox) is assigned with a model, a default renderer is assigned too. The default renderer will assume that each list item has only one column, and it converts the data into a string directly[1]. If you want to display multiple columns or retrieve a particular field of the data, you have to implement ListitemRenderer to handle the rendering.

For example,

public class MyRenderer implements ListitemRenderer{
	public void render(Listitem listitem, Object data, int index) {
		Listcell cell = new Listcell();
		if (data instanceof String[]){
			cell.appendChild(new Label(((String[])data)[0].toString()));
		} else if (data instanceof String){
			cell.appendChild(new Label(data.toString()));
		} else {
			cell.appendChild(new Label("UNKNOW:"+data.toString()));

  1. If the listbox is assigned a template called model, then the template will be used to render the listbox. For more information, please refer to the Listbox Template section.

Version History

Version Date Content
6.0.0 February 2012 The index argument was introduced.

Last Update : 2022/07/08

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