symfony trying to export a csv file from a link - symfony

Question

I have this function in the controller, that returns a form with a select box. When the values are selected, I retrieve them with
$manifestations = $form['manifestations']->getData();
then put them in a repository function that queries the database $invites = $repository->searchInviteByManif($manifestations);
public function indexAction() {
$entity = new Invite();
$form = $this->createForm(new ManifSearchType(), $entity);
$request = $this->get('request');
$invites = null;
if ($request->getMethod() == 'POST') {
$form->handleRequest($request);
$message = '';
$manifestations = $form['manifestations']->getData();
$repository = $this->getDoctrine()
->getManager()
->getRepository('PrifProtocoleBundle:Invite');
$invites = $repository->searchInviteByManif($manifestations);
$response1 = $this->render('PrifProtocoleBundle:Invite:index.html.twig', array(
'form' => $form->createView(),
'entities' => $invites,
'message' => $message,
));
return $response1;
}
return array(
'form' => $form->createView(),
'entities' => $invites,
);
}
This function then returns a view index.html.twig with a table and all the fields found in the db.
What I want is to export all the queried data $invites in a CSV file, by clicking on a link directly from the HTML table.
So I've put an href="" link in the Twig file,
{% if message is defined %}
<div class="pdf">
<img height="40px" width="40px" src={{ asset('bundles/prifprotocole/images/excel.jpg') }}>
{% for entity in entities %}
<tr class="{{ cycle(['odd', 'even'], loop.index0) }}">
<td>{% if entity.etat == 1 %} Actif {% else %} Inactif {% endif %}</td>
<td>{{ entity.titreGrade }} {{ entity.prenom }} {{ entity.nom }}</td>
<td>{{ entity.fonction }}</td>
This is how I use to export the CSV file without the link :
$response2 = $this->render('PrifProtocoleBundle:Invite:export.csv.twig', array(
'entities' => $invites));
$response2->headers->set('Content-Type', 'text/csv');
$csvfile = $response2->headers->set('Content-Disposition', 'attachment; filename="export.csv"');
return $csvfile;
export.csv.twig file
{% for entity in entities %}
Id {{ entity.id }};
Etat {{ entity.etat }};
Titregrade {{ entity.titreGrade }};
Prenom {{ entity.prenom }};
Nom {{ entity.nom }};
Fonction {{ entity.fonction }};
{% endfor %}
Can someone give me a detailed solution on how to perform this? Much thanks!

Answer 1

You should simply pass the filter criterias, here the $manifestations array as a route parameter, by serializing it first.
Then, you should put a controller like downloadCsvAction() handling this route, querying the $invites from the database, and rendering your export.csv.twig template.
Another option, if you cannot serialize the data in URI, is to create a form with hidden fields containing the data. Then you replace the download link with the submit button of this hidden form.

Answer 2

Guillaume's answer is great if you don't mind fetching your data twice. Once when you display your page, and then when you download the CSV. Another way to do this is to cache the answer. I will give an example using memcache (which is what I use).
First, make sure that memcache is active in your php.ini.
Then before rendering your first page (after fetching the data), cache it:
$key = "csv.$userId";
$memcache = new \Memcache();
$memcache->connect($yourServerHost, $yourServerPort);
$memcache->set($key, json_encode($invites), MEMCACHE_COMPRESSED, 86400); // 24h
The trick is to find a good key, to add your report to the cache, and then be able to retrieve it. It has to be unique. Here, I assume that you have a user that is logged in, and I use the user ID to create a key. If that is not the case, you could create yourself a token, and pass it when rendering the page (along with $invites). This way, you can add the token to the URL to generate the CSV.
Then, in your second action, where you download the CSV, you just fetch the cached data:
$memcache = new \Memcache();
$memcache->connect($yourServerHost, $yourServerPort);
$json = $memcache->get($key);
$invites = json_decode($json , true);
That's it. You should probably create yourself a service for Memcache, so you don't have to create an object, and connect everytime.