smartdrops.php

<?php
defined( '_JEXEC' ) or die;

/**
 * An helper class for generating dropdowns in Joomla.
 *
 * @package default
 * @author Joseph LeBlanc
 */
class SmartDrops
{
	private $value_source;
	private $input_name;
	private $value;
	private $source_type;

	/**
	 * Expects the name of the dropdown you're generating, along with a value
	 * source. The value source can be an array of values, or an SQL query. If
	 * an SQL query is used, it MUST return the columns 'value' and 'text' for
	 * the option values and labels, repsectively. Also allows the value to be
	 * preset.
	 *
	 * @param string $input_name 
	 * @param mixed $value_source 
	 * @param mixed $value
	 * @throws Exception
	 * @author Joseph LeBlanc
	 */
	function __construct($input_name, $value_source, $value = 0, $source_type = 'single')
	{
		if (!is_array($value_source) && !is_string($value_source)) {
			throw new Exception("The value source for SmartDrops must either be an SQL query or array of values");
		}

		$this->value_source = $value_source;
		$this->input_name = $input_name;
		$this->value = $value;
		$this->source_type = $source_type;
	}

	/**
	 * Generates the dropdown based on the preset value source and input name.
	 * Optionally, you can override the default value as well as its label.
	 *
	 * @param string $default_value 
	 * @param string $default_label 
	 * @return void
	 * @author Joseph LeBlanc
	 */
	public function generateDropdown($default_value = 0, $default_label = '-select-')
	{
		// If SQL, run it and get values. Otherwise, make from array.
		if (is_string($this->value_source)) {
			$options = $this->getOptionsFromSQL();
		} else {
			$options = $this->getOptionsFromArray();
		}

		$option = JHTML::_('select.option', $default_value, $default_label);
		$options = array_merge(array($option), $options);

		$dropdown = JHTML::_('select.genericlist', $options, $this->input_name, null, 'value', 'text', $this->value);

		return $dropdown;
	}

	private function getOptionsFromSQL()
	{
		$database =& JFactory::getDBO();
		$database->setQuery($this->value_source);
		return $database->loadObjectList();
	}

	private function getOptionsFromArray()
	{
		$options = array();

		foreach ($this->value_source as $key => $label) {
			if ($this->source_type == 'keyed') {
				$options[] = JHTML::_('select.option', $key, $label);
			} else {
				// single elements
				$options[] = JHTML::_('select.option', $label, $label);
			}
		}

		return $options;
	}

	public function __tostring()
	{
		return $this->generateDropdown();
	}
}