core-bundle/src/Resources/contao/forms/FormRadioButton.php
public function generate()
	{
		$strOptions = '';

		foreach ($this->arrOptions as $i=>$arrOption)
		{
			$strOptions .= sprintf('<span><input type="radio" name="%s" id="opt_%s" class="radio" value="%s"%s%s%s <label id="lbl_%s" for="opt_%s">%s</label></span> ',
									$this->strName,
									$this->strId.'_'.$i,
									$arrOption['value'],
									$this->isChecked($arrOption),
									$this->getAttributes(),
									$this->strTagEnding,
									$this->strId.'_'.$i,
									$this->strId.'_'.$i,
									$arrOption['label']);
		}

		if ($this->strLabel != '')
		{
			return sprintf('<fieldset id="ctrl_%s" class="radio_container%s"><legend>%s%s%s</legend>%s<input type="hidden" name="%s" value=""%s%s</fieldset>',
							$this->strId,
							(($this->strClass != '') ? ' ' . $this->strClass : ''),
							($this->mandatory ? '<span class="invisible">'.$GLOBALS['TL_LANG']['MSC']['mandatory'].' </span>' : ''),
							$this->strLabel,
							($this->mandatory ? '<span class="mandatory">*</span>' : ''),
							$this->strError,
							$this->strName,
							$this->strTagEnding,
							$strOptions);
		}
		else
		{
	        return sprintf('<fieldset id="ctrl_%s" class="radio_container%s">%s<input type="hidden" name="%s" value=""%s%s</fieldset>',
							$this->strId,
							(($this->strClass != '') ? ' ' . $this->strClass : ''),
							$this->strError,
							$this->strName,
							$this->strTagEnding,
							$strOptions);
		}
	}
public function generate()
	{
		$strOptions = '';

		foreach ($this->arrOptions as $i=>$arrOption)
		{
			$strOptions .= sprintf('<span><input type="radio" name="%s" id="opt_%s" class="radio" value="%s"%s%s%s <label id="lbl_%s" for="opt_%s">%s</label></span> ',
									$this->strName,
									$this->strId.'_'.$i,
									$arrOption['value'],
									$this->isChecked($arrOption),
									$this->getAttributes(),
									$this->strTagEnding,
									$this->strId.'_'.$i,
									$this->strId.'_'.$i,
									$arrOption['label']);
		}

		if ($this->strLabel != '')
		{
			return sprintf('<fieldset id="ctrl_%s" class="radio_container%s"><legend>%s%s%s</legend>%s<input type="hidden" name="%s" value=""%s%s</fieldset>',
							$this->strId,
							(($this->strClass != '') ? ' ' . $this->strClass : ''),
							($this->mandatory ? '<span class="invisible">'.$GLOBALS['TL_LANG']['MSC']['mandatory'].' </span>' : ''),
							$this->strLabel,
							($this->mandatory ? '<span class="mandatory">*</span>' : ''),
							$this->strError,
							$this->strName,
							$this->strTagEnding,
							$strOptions);
		}
		else
		{
	        return sprintf('<fieldset id="ctrl_%s" class="radio_container%s">%s<input type="hidden" name="%s" value=""%s%s</fieldset>',
							$this->strId,
							(($this->strClass != '') ? ' ' . $this->strClass : ''),
							$this->strError,
							$this->strName,
							$this->strTagEnding,
							$strOptions);
		}
	}
Generate the widget and return it as string

@return string The widget markup