Symfony2嵌套形式和ManyTo许多关系

Question

我正在尝试处理一个对我来说相当复杂的表格...

我们有收藏，其中包含书籍（OneTo多国），文章（OneTo多国）及其作者（ManyTo多国）。

用户可以编辑一本书：他可以添加或删除一篇文章，还可以为每篇文章添加或删除一些作者。有嵌套表单：book

实体描述看起来很好，数据库是由控制台生成的，看起来是一致的。

如果我不必与使用图书版表单的作者打交道，这就很好了。如果作者存在，我有一个重复条目错误。如果作者是新的，我有一个“显式持久化新实体或在关系上配置级联持久化操作”错误。

代码如下：

public function onSuccess(Book $book)
{   
    $this->em->persist($book);

    foreach($book->getArticles() as $article)  
    {
        $article->setUrlname($this->mu->generateUrlname($article->getName()));
        $article->setBook($book);

        // Saving (and creating) the authors of the book
        foreach ($this->collectionWithAuthors->getAuthors() as $existAuthor){      
            foreach($article->getAuthors() as $author) {                        
                $authorUrlname=$this->mu->generateUrlname($author->getFirstname().' '.$author->getLastname());
                if ( $existAuthor->getUrlname() ==  $authorUrlname) { // The author is existing
                    $article->addAuthor($existAuthor);
                    $this->em->persist($existAuthor);
                }else{                                                // New Author
                    $newAuthor = new Author();                                
                    $newAuthor->setCollection($this->collectionWithBaseArticles);
                    $newAuthor->setLastname($author->getLastname());
                    $newAuthor->setFirstname($author->getFirstname());
                    $newAuthor->setUrlname($authorUrlname);
                    $this->em->persist($newAuthor);
                    $article->addAuthor($newAuthor);                          
                }
            }
        }
        $this->em->persist($article);

    }
    $this->em->flush();

}

我不知道如何使用级联。但是$文章-

文章实体摘录

/**
* @ORM\ManyToMany(targetEntity="bnd\myBundle\Entity\Author", mappedBy="articles")
*/
private $authors;

/**
 * Add authors
 *
 * @param bnd\myBundle\Entity\Author $authors
 * @return Article
 */

public function addAuthor(\bnd\myBundle\Entity\Author $authors)
{
    $this->authors[] = $authors;
    $authors->addArticle($this);
}

Answer 1

foreach语句中的逻辑错误。假设我们有下一位作者：

• 持久化作者（collectionWithAuthors）：
  • 约翰
  • 埃里克
  • Ada

  因此，对于每个现有作者（John和Eric），脚本都会循环到新作者：

  foreach ([John, Eric] as $author) {
      foreach([Ada, Eric] as $newAuthor) {
          // John author: the script persist Ada(right) and Eric(wrong) as new authors
          // Eric author: the script persist Ada(wrong), but not Eric(right)
      }
  }
  

  解决方案是用现有作者替换文章作者（如果有类似的）

  foreach ($article->getAuthors() as $key => $articleAuthor) {
      $authorUrlname=$this->mu->generateUrlname($articleAuthor->getFirstname().' '.$articleAuthor->getLastname());
      $foundAuthor = false;
      // Compare article author with each existing author
      foreach ($this->collectionWithAuthors->getAuthors() as $existAuthor) { 
          if ($existAuthor->getUrlname() ==  $authorUrlname) {
              $foundAuthor = true;
              break; // It has found similar author no need to look further
          }
      }
  
      // Use $existAuthor as found one, otherwise use $articleAuthor
      if ($foundAuthor) {
          $article->removeAuthor($articleAuthor); // Remove submitted author, so he wont be persisted to database
          $article->addAuthor($existAuthor);
      } else {
          // Here you dont need to create new author                          
          $articleAuthor->setCollection($this->collectionWithBaseArticles);
          $articleAuthor->setUrlname($authorUrlname);
      }
  
      ...
  }
  
  $this->_em->persist($article);
  

  您已经注意到，我从循环中删除了任何author persistent，为了持久化这些author，最好在Article实体类的$authors注释中设置cascade={'persistent}

  /**
   * @ORM\ManyToMany(targetEntity="Author", cascade={"persist"})
   * @ORM\JoinTable(...)
   */
  protected $authors;
  

  UPD：

  关于cascade persistent，我忘了提一件事。要保持文章和作者之间的关系，还必须将关系添加到作者实体。编辑文章实体中的addAuthor（）方法，如下所示：

  public function addAuthor(Author $author)
  {
      // Only add author relation if the article does not have it already
      if (!$this->authors->contains($author)) {
          $this->authors[] = $author;
          $author->addArticle($this);
      }
  }
  

  此外，为构造函数中的实体集合定义默认值也是一种很好的做法：

  use Doctrine\Common\Collections\ArrayCollection;
  
  // ...
  
  public function __construct()
  {
      $this->authors = new ArrayCollection();
  }