Moodle在表现层的实现有多种机制，分别针对页面、表单、导航条、页面头部、页面底部等。

　　1、针对页面的实现，直接编辑HTML页面，然后在业务逻辑处理完毕之后，include编辑好的html页面即可。这种机制的实现可以看login/index.php和 login/index_form.php页面。

　　2、针对表单的实现，一般是创建一个父类为moodleform的类，如

class test_form extends moodleform {//定义表单元素function definition() {//获得表单引用$mform =& $this->_form;//添加header对象$mform->addElement('header', '', get_string('createuserandpass'), '');//添加text对象，$mform->addElement('text', 'username', get_string('username'), 'maxlength="100" size="12"');$mform->setType('username', PARAM_NOTAGS);$mform->addRule('username', get_string('missingusername'), 'required', null, 'server');}//定义过滤function definition_after_data(){}//定义验证逻辑function validation($data, $files) {}}

　　然后，业务逻辑层中声明test_form对象，即

$test = new test _form();

　　最后调用test_form对象的display方法，即可把表单对象显示出来。

$test ->display();

　　表单元素的类型和规则如下：

$GLOBALS['HTML_QUICKFORM_ELEMENT_TYPES'] =array('group'         =>array('HTML/QuickForm/group.php','HTML_QuickForm_group'),'hidden'        =>array('HTML/QuickForm/hidden.php','HTML_QuickForm_hidden'),'reset'         =>array('HTML/QuickForm/reset.php','HTML_QuickForm_reset'),'checkbox'      =>array('HTML/QuickForm/checkbox.php','HTML_QuickForm_checkbox'),'file'          =>array('HTML/QuickForm/file.php','HTML_QuickForm_file'),'image'         =>array('HTML/QuickForm/image.php','HTML_QuickForm_image'),'password'      =>array('HTML/QuickForm/password.php','HTML_QuickForm_password'),'radio'         =>array('HTML/QuickForm/radio.php','HTML_QuickForm_radio'),'button'        =>array('HTML/QuickForm/button.php','HTML_QuickForm_button'),'submit'        =>array('HTML/QuickForm/submit.php','HTML_QuickForm_submit'),'select'       =>array('HTML/QuickForm/select.php','HTML_QuickForm_select'),'hiddenselect' =>array('HTML/QuickForm/hiddenselect.php','HTML_QuickForm_hiddenselect'),'text'          =>array('HTML/QuickForm/text.php','HTML_QuickForm_text'),'textarea'      =>array('HTML/QuickForm/textarea.php','HTML_QuickForm_textarea'),'link'          =>array('HTML/QuickForm/link.php','HTML_QuickForm_link'),'advcheckbox'   =>array('HTML/QuickForm/advcheckbox.php','HTML_QuickForm_advcheckbox'),'date'          =>array('HTML/QuickForm/date.php','HTML_QuickForm_date'),'static'        =>array('HTML/QuickForm/static.php','HTML_QuickForm_static'),'header'        =>array('HTML/QuickForm/header.php', 'HTML_QuickForm_header'),'html'          =>array('HTML/QuickForm/html.php', 'HTML_QuickForm_html'),'hierselect'    =>array('HTML/QuickForm/hierselect.php', 'HTML_QuickForm_hierselect'),'autocomplete' =>array('HTML/QuickForm/autocomplete.php', 'HTML_QuickForm_autocomplete'),'xbutton'       =>array('HTML/QuickForm/xbutton.php','HTML_QuickForm_xbutton'));$GLOBALS['_HTML_QuickForm_registered_rules'] = array('required'      => array('html_quickform_rule_required', 'HTML/QuickForm/Rule/Required.php'),'maxlength'     => array('html_quickform_rule_range',    'HTML/QuickForm/Rule/Range.php'),'minlength'     => array('html_quickform_rule_range',    'HTML/QuickForm/Rule/Range.php'),'rangelength'   => array('html_quickform_rule_range',    'HTML/QuickForm/Rule/Range.php'),'email'         => array('html_quickform_rule_email',    'HTML/QuickForm/Rule/Email.php'),'regex'         => array('html_quickform_rule_regex',    'HTML/QuickForm/Rule/Regex.php'),'lettersonly'   => array('html_quickform_rule_regex',    'HTML/QuickForm/Rule/Regex.php'),'alphanumeric' => array('html_quickform_rule_regex',    'HTML/QuickForm/Rule/Regex.php'),'numeric'       => array('html_quickform_rule_regex',    'HTML/QuickForm/Rule/Regex.php'),'nopunctuation' => array('html_quickform_rule_regex',    'HTML/QuickForm/Rule/Regex.php'),'nonzero'       => array('html_quickform_rule_regex',    'HTML/QuickForm/Rule/Regex.php'),'callback'      => array('html_quickform_rule_callback', 'HTML/QuickForm/Rule/Callback.php'),'compare'       => array('html_quickform_rule_compare', 'HTML/QuickForm/Rule/Compare.php'));

　　具体可以查看lib/pear/HTML/QuickForm.php，和各个表单元素和规则的实现文件。

来源：http://www.goodu.info/gc/node/354