制作一个包含两个子表单的表单类型。

  class MergedFormType 

 $ builder-> add（'topic'，new TopicFormType（））; 
 $ builder-> add（'post'，new PostFormType（））; 
 

在你的控制器中传递一个数组到MergedFormType

  public function myAction（）

 $ formData ['topic'] = $ topic; 
 $ formData ['post'] = $ post; 

 $ form = $ this-> createForm（new MergedFormType（），$ formData）; 
 

I'm trying to create a very simple forum with Symfony2.

My entities are: ForumCategory (name, description...) ForumTopic (category_id, title) ForumPost (isFirstPost, body, topic_id, author_id...)

When a user try to create a Topic, I want to display only one form in the same page to create a Topic and the first post message. Like:

• Insert topic title: ...
• Insert topic body (related Post Body): ...

[...]

How can I do that? It's possible merge two form in this case?

Make a form type that contains both of your sub forms.

class MergedFormType

    $builder->add('topic', new TopicFormType());
    $builder->add('post',  new PostFormType());

In your controller just pass an array to MergedFormType

public function myAction()

    $formData['topic'] = $topic;
    $formData['post']  = $post;

    $form = $this->createForm(new MergedFormType(), $formData);