添加多条记录，字段为空则不添加（bind）

目的：
用户自定义数目的记录，有内容的input则插入数据库，没内容则忽略
例子：

已经embed的字段要用unset()才不会插入数据库

/lib/.../xxForm.class.php
...
public function addNewTargets($number) {
        $targets = new sfForm();
        for($i=0;$i<$number;$i++) {
            $target = new WeightTarget();
            $target->setWeightWatcher($this->getObject());
            $target_from = new WeightTargetForm($target);
            $targets->embedForm($i, $target_from);
        }
        $this->embedForm('new', $targets);
    }
  public function bind(array $taintedValues = null, array $taintedFiles = null){
    $new_targets = new sfForm();
    $taintedValues['user_simple_id'] = sfContext::getInstance()->getUser()->getGuardUser()->getId();
    foreach($taintedValues['new'] as $key => $new_target){

      if(!empty ($new_target['title'])){
          $target = new WeightTarget();
          $target->setWeightWatcher($this->getObject());
          $target_form = new WeightTargetForm($target);
          $new_targets->embedForm($key,$target_form);
      }else{ //字段为空则unset()
          unset ($taintedValues['new'][$key]);
      }
    }

    $this->embedForm('new',$new_targets);
    }
    parent::bind($taintedValues, $taintedFiles);
  }

#.apps/.../actions.class.php
public function executeNew(sfWebRequest $request)
  {
    $this->number = 5;#显示5条执行事项
    $this->form = new WeightWatcherForm();
    $this->form->addNewTargets($this->number);
  }

#template
...
<?php include_partial('addTargets', array('form'=>$form,'number'=>$number))?>
...

#partial
<?php for($i=0;$i<$number;$i++):?>
<tr>
    <th scope=”row”><?php if($i<9) echo ’0′.($i+1); else echo $i+1;?>.</th>
    <td>
        <?php echo $form['new'][$i]['title']->render(array(‘class’=>’target_list’))?>
    </td>
</tr>
<?php endfor;?>

如果提交create时发现有非法字段，我们会发现提示错误。因为现在的记录数已经不是5条。所以我们要重新设置记录数：

...
public function executeCreate(sfWebRequest $request)
  {
$post = $request->getPostParameters();

    $this->number = count($post['weight_watcher']['new']);#显示5条执行事项
    $this->form = new WeightWatcherForm();
    $this->form->addNewTargets($this->number);
...
}
...

就ok了。