How to use Ajax within Sonata Admin forms?

I was able to make this work a few months back. While what a.aitboudad has shared is accurate. There are a few gotcha’s that first timers with Symfony/Sonata might face.

Here are the steps.

1> Extend Sonata CRUD’s edit.html.twig / base_edit.html.twig .
For simplicity, I’ll use only the latter.
Copy vendor/bundles/Sonata/AdminBundle/Resources/views/CRUD/base_edit.html.twig into the views folder corresponding to the MerchantAdminController – YourBundle/Resources/views/Merchant/base_edit.html.twig

2> We need to tell our MerchantAdmin class to use this template. So we override SonataAdmin’s getEditTemplate method like this:

public function getEditTemplate()
{
    return 'YourBundle:Merchant:base_edit.html.twig';
}

3> Next we need to code the Ajax functionality in our base_edit.html.twig . Standard Ajax comprises of the following:

3.1> — Create an Action in the controller for the Ajax request
We primarily want to get a list of category IDs corresponding to a particular tag. But most likely you are just using Sonata’s CRUD Controller.

Define your MerchantAdminController which extends CRUDController

<?php

namespace GD\AdminBundle\Controller;

use Sonata\AdminBundle\Controller\CRUDController as Controller;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use GD\AdminBundle\Entity\Merchant;

class MerchantAdminController extends Controller
{

}

3.2> — Tell your Admin service to use this newly created controller instead of the default CRUDController by defining it in YourBundle/Resources/config/services.yml

gd_admin.merchant:
        class: %gd_admin.merchant.class%
        tags:
            - { name: sonata.admin, manager_type: orm, group: gd_merchant, label: Merchants }
        arguments: [null, GD\AdminBundle\Entity\Merchant, GDAdminBundle:MerchantAdmin]

Notice that the 3rd argument is the name of your controller. By default it would have been null.

3.3> — Create an Action named getCategoryOptionsFromTagAction in your controller. Your Ajax call will be to this Action.

// route - get_categories_from_tag
public function getCategoryOptionsFromTagAction($tagId)
    {   
        $html = ""; // HTML as response
        $tag = $this->getDoctrine()
            ->getRepository('YourBundle:Tag')
            ->find($tagId);

        $categories = $tag->getCategories();

        foreach($categories as $cat){
            $html .= '<option value="'.$cat->getId().'" >'.$cat->getName().'</option>';
        }

        return new Response($html, 200);
    }

3.4> — Create the corresponding route in app/config/routing.yml. Remember to expose your route if you are using the FOSJsRoutingBundle (else you’ll have to hardcode which is not a good idea).

get_categories_from_tag:
    pattern: /{_locale}/admin/gd/admin/merchant/get-categories-from-tag/{tagId}
    defaults: {_controller: GDAdminBundle:MerchantAdmin:getCategoryOptionsFromTag}
    options:
        expose: true

3.5> — Make the Ajax Request and use the response

{% block javascripts %}
    {{ parent() }}
    <script type="text/javascript">

        $(document).ready(function(){
            var primaryTag = $("#{{ admin.uniqId }}_primaryTag");
            primaryTag.change(updateCategories()); // Bind the function to updateCategories
            primaryTag.change(); // Manual trigger to update categories in Document load.

            function updateCategories(){
                return function () {
                    var tagId = $("#{{ admin.uniqId }}_primaryTag option:selected").val();
                    var primaryCategory = $("#{{ admin.uniqId }}_primaryCategory");
                    primaryCategory.empty();
                    primaryCategory.trigger("liszt:updated");
                    var locale="{{ app.request.get("_locale') }}';

                    var objectId = '{{ admin.id(object) }}'

                    var url = Routing.generate('get_categories_from_tag', { '_locale': locale, 'tagId': tagId, _sonata_admin: 'gd_admin.merchant', id: objectId });
                    $.post(url, { tagId: tagId }, function(data){
                        primaryCategory.empty().append(data);
                        primaryCategory.trigger("liszt:updated");
                    },"text");

                    primaryCategory.val("option:first").attr("selected", true);
                };
            }
        });
    </script>
{% endblock %}

Gotcha 1: How to get the Unique ID that is appended to all Sonata elements

Solution: Use the admin variable which will give you access to all the Admin Class’s properties including uniqId. See code on how to use it.

Gotcha 2: How to get the Router in your JS.

Solution: By default Symfony2 Routing doesn’t work in JS. You need to use a bundle called FOSJSRouting (explained above) and expose the route. This will give you access to the Router object within your JS too.

I have modified my solution slightly to make this example clearer. If you notice anything wrong, please feel free to comment.