Building a Dynamic Select - RIFE

Many websites require <select> form elements that pull their data dynamic. A classic example is a <select> populated with information from a database. RIFE has no native support for dynamic <selects>, but implementing one isn't that difficult. Below is a class that makes the process painless on the template designed and the developer.

package com.warfrog.portal.helpers;

import java.util.List;
import java.util.logging.Logger;

import com.uwyn.rife.engine.Element;
import com.uwyn.rife.template.Template;
import com.uwyn.rife.tools.BeanUtils;
import com.uwyn.rife.tools.exceptions.BeanUtilsException;

public class FormsHelper extends Element {
	private FormsHelper() {}
	public static void buildSelect(Template dynamicselect, Template template,
			String identifier, List beans, String valueProperty,
			String displayTextProperty) {		
		String id = identifier.substring(identifier.lastIndexOf(':') + 1);
		dynamicselect.setValue("id", id);
		try {
			for (Object o : beans) {
				dynamicselect.setValue("value", BeanUtils.getPropertyValue(o,
						valueProperty));
				dynamicselect.setValue("text", BeanUtils.getPropertyValue(o,
						displayTextProperty));
				dynamicselect.appendBlock("options", "option");
			}
		} catch (BeanUtilsException e) {
			Logger.getLogger("FormHelper").warning(
					"Error building the <select>");
		}
		template.setValue(identifier, dynamicselect);
	}
}

Make sure to place the following template in your "template/common" directory as the helper uses the template to build the selects.

<r:v name="select"/>

<r:bv name="select">
	<select name="<r:v name="id"/>">
	<r:v name="options"/>
	</select>
</r:bv>

<r:b name="option">
	<option value="<r:v name="value"/>"><r:v name="text"/></option>
</r:b>

To use the class you'd do something like this inside your element:

public class SomeElement extends Element {
	public void processElement() {
		Template template = getHtmlTemplate("testers.article");
		FormsHelper.buildSelect(getHtmlTemplate("common.dynamicselect"), template, "FORM:SELECT:categoryId", new CategoryManager().restore(), "id", "name");
		print(template);
	}
}

and the sample template

<form name="some_element_data" 
      action="${v SUBMISSION:FORM:some_element_data/}" 
      method="post">	
    <r:v name="SUBMISSION:PARAMS:some_element_data"/>
    <r:v name="FORM:INPUT:title"/>
    <r:v name="FORM:TEXTAREA:body"/>
    <r:v name="FORM:SELECT:someselectelement"/>
    <input type="submit"/>
</form>

The code above simply calls FormsHelper.buildSelect(...) with the template to modify, the full name of the select element, a List of beans to work with, the field of the bean to use as the <option> value, and the field of the bean to use as the <option> text. It's that simple.