How to use existing entity in a Symfony2 form?

Question

I've this two entities:

class Article
{
    /** @var ArrayCollection
    protected $tags;
}

class Tag
{
    protected $id;
    protected $name;
}

Basically I've read http://symfony.com/doc/master/cookbook/form/form_collections.html but it does not explain my case.

Let me explain.

I've existing tags in database, so I want to be able to associate multiple Tags to my Article, I don't want to allow the creation of inexistent tags.

Since I'm aiming to use my form in both a REST api and with a web form, I'd like my client be able to use the id only to reference the tags (which would have been fetched before).

Any ideas?

Answer 1

You could use the entity field typ e. It is in practice a choice field type that you can render as a select with multiple selection or as a list of checkboxes . However, if you have many tags there will be too many options and the users will not be happy.

So, I suggest to implement a Stackoverflow-like tagging system.

I did it in a project by using a Javascript tokeninput library, like this by loopj . In practice:

1. You should first render a text field named tags .

2. Then you should handle the tag insertion to that input field with the Javascript library for token handling.

3. The Controller will receive a tokenized string that you have to handle in order to retrieve the Tag entities from Doctrine.

4. Finally, retrieved a list of Tag entities, assign them to your Article entity and flush everything.

Answer 2

You can use somethig like this:

$builder->add('tags', 'entity', array(
    'class' => 'AcmeHelloBundle:tag',
    'expanded' => true,
    'multiple' => true,
));