Using Symphony Forms Component with Grav

Archive
1

It would be cool if we could use Symfony’s forms component with Grav, in order to create more flexible forms.
Right now, I’m just trying to get it to work in a theme, but in the future there will be a standalone ‘advanced forms’ plugin.
So Far
composer require symfony/form

In the theme’s main file
require_once __DIR__ . '/vendor/autoload.php';

I’m following the examples in the Symfony Book: https://symfony.com/doc/master/book/forms.html

Importing stuff

use Symfony\Component\Form\Forms;
use Symfony\Component\Form\Extension\Core\Type\TextType;
use Symfony\Component\Form\Extension\Core\Type\DateType;
use Symfony\Component\Form\Extension\Core\Type\SubmitType;

This runs when the onTwigSiteVariables event fires:

$formFactory = Forms::createFormFactory();
    
$form = $formFactory->createBuilder()
  ->add('task', TextType::class)
  ->add('dueDate', DateType::class)
  ->add('save', SubmitType::class, array('label' => 'Create Task'))
  ->getForm();

And a form object actually gets created. Hooray!

The Question

How do I actually render the form using:

{{ form_start(form) }}
{{ form_widget(form) }}
{{ form_end(form) }}

…in one of the theme’s template files?

2

You need to expose those functions to Twig. For example see how the Comments plugin exposes the comments: https://github.com/getgrav/grav-plugin-comments/blob/develop/comments.php#L56-L64 or how Admin adds Twig filters (a similar approach is for Twig functions): https://github.com/getgrav/grav-plugin-admin/blob/develop/twig/AdminTwigExtension.php - https://github.com/getgrav/grav/blob/develop/system/src/Grav/Common/Twig/TwigExtension.php.

That said, Grav has a Form Plugin that could be extended with proposals to make it more powerful and flexible. What do you miss in it now?

3

I’ll check out those examples.
There are two features that would make the Form plugin really great:

  1. The ability to output a form anywhere in a page (maybe with something like a short code, or twig function)
  2. Being able to add arbitrary HTML between the form inputs
4

You could use a display or spacer field to output some text. Not sure it accepts any HTML, need to check.

Add a form anywhere is something missing. You can add this as an issue on https://github.com/getgrav/grav-plugin-form/issues to keep track of possible enhancements.