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Prepending Config

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I'm pretty sure that our new item_view is configured correctly. We have item\value_type: contentful_entry, which I know is correct... and then we're using contentful\content_type set to skill so that this only affects skills:

... lines 2 - 12
... lines 15 - 21
# default = frontend
... lines 24 - 28
template: '@nglayouts/item/contentful_entry/skill.html.twig'
item\value_type: 'contentful_entry'
contentful\content_type: 'skill'
... lines 34 - 41

But... it doesn't seem to be working on the frontend. Earlier, when we ran debug:config, we saw that the problem lies with the order of the config. Layouts reads from top to bottom when deciding which "view" to use. So it looks at this one first, sees that the value_type is contentful_entry... and just stops. To fix this, we need to reverse our config.

Ok, so... why is it in this order to begin with? Why does our config show up at the bottom? This is due to how Symfony loads config: it loads bundle config first - like from the Contentful package or Layouts - and then loads our configuration files. And, that's usually the order we want! It allows us to override configuration that's set in bundles.

But in this case, we want the opposite. How do we accomplish that? By asking Symfony to prepend our configuration.

Setting up the Prepend

In the config/ directory, create a new directory called prepends/ and move the Netgen Layouts configuration into it. This will stop Symfony from loading that file in the normal way: we're going to load it manually.

The next step is a bit technical. In src/, create an "extension" class called, how about, AppExtension. I'm going to paste in the code: you can grab this from the code block on this page:

... lines 1 - 2
namespace App;
use Symfony\Component\Config\Resource\FileResource;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Extension\Extension;
use Symfony\Component\DependencyInjection\Extension\PrependExtensionInterface;
use Symfony\Component\Yaml\Yaml;
class AppExtension extends Extension implements PrependExtensionInterface
public function load(array $configs, ContainerBuilder $container)
public function prepend(ContainerBuilder $container)
$configFile = __DIR__ . '/../config/prepends/netgen_layouts.yaml';
$config = Yaml::parse((string) file_get_contents($configFile));
$container->prependExtensionConfig('netgen_layouts', $config['netgen_layouts']);
$container->addResource(new FileResource($configFile));

This loads our config file like normal... except that it will be prepended.

Final step. To get this method to be called, open up the Kernel class. After use MicroKernelTrait, add configureContainer as baseConfigureContainer:

22 lines src/Kernel.php
... lines 1 - 10
class Kernel extends BaseKernel
use MicroKernelTrait { configureContainer as baseConfigureContainer; }
... lines 14 - 20

This adds the configureContainer method from MicroKernelTrait into this class like a trait normally would... except that it renames it to baseConfigureContainer. We're doing this so that we can define our own configureContainer() method. Copy the configureContainer() signature from the trait, paste, hit "OK" to add the use statements and then call $this->baseConfigureContainer() passing $container, $loader, and $builder:

22 lines src/Kernel.php
... lines 1 - 5
use Symfony\Component\Config\Loader\LoaderInterface;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator;
... lines 9 - 10
class Kernel extends BaseKernel
... lines 13 - 14
private function configureContainer(ContainerConfigurator $container, LoaderInterface $loader, ContainerBuilder $builder): void
$this->baseConfigureContainer($container, $loader, $builder);
... lines 18 - 19

The configureContainer() method in the trait is responsible for loading services.yaml as well as all of files inside config/packages/. That's all good stuff that we want to keep doing. But after doing that, add one more thing: $builder->registerExtension(new AppExtension()):

22 lines src/Kernel.php
... lines 1 - 10
class Kernel extends BaseKernel
... lines 13 - 14
private function configureContainer(ContainerConfigurator $container, LoaderInterface $loader, ContainerBuilder $builder): void
$this->baseConfigureContainer($container, $loader, $builder);
$builder->registerExtension(new AppExtension());

Again, yes, this is annoyingly technical. But thanks to these two pieces, our netgen_layouts.yaml config will be prepended.

Check it out! Re-run the debug:config command again:

php ./bin/console debug:config netgen_layouts view.item_view

Scroll up and... yes! Our configuration is now on top! And when we refresh... woohoo! We see the text!

Next: let's make this template render exactly like the hardcoded skills. Then we'll create a second item template to customize how the Contentful "Advertisement" content type renders.

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What PHP libraries does this tutorial use?

// composer.json
    "require": {
        "php": ">=8.1.0",
        "ext-ctype": "*",
        "ext-iconv": "*",
        "babdev/pagerfanta-bundle": "^3.7", // v3.7.0
        "doctrine/doctrine-bundle": "^2.7", // 2.7.0
        "doctrine/doctrine-migrations-bundle": "^3.2", // 3.2.2
        "doctrine/orm": "^2.13", // 2.13.3
        "easycorp/easyadmin-bundle": "^4.4", // v4.4.1
        "netgen/layouts-contentful": "^1.3", // 1.3.2
        "netgen/layouts-standard": "^1.3", // 1.3.1
        "pagerfanta/doctrine-orm-adapter": "^3.6",
        "sensio/framework-extra-bundle": "^6.2", // v6.2.8
        "stof/doctrine-extensions-bundle": "^1.7", // v1.7.0
        "symfony/console": "5.4.*", // v5.4.14
        "symfony/dotenv": "5.4.*", // v5.4.5
        "symfony/flex": "^1.17|^2", // v2.2.3
        "symfony/framework-bundle": "5.4.*", // v5.4.14
        "symfony/monolog-bundle": "^3.0", // v3.8.0
        "symfony/proxy-manager-bridge": "5.4.*", // v5.4.6
        "symfony/runtime": "5.4.*", // v5.4.11
        "symfony/security-bundle": "5.4.*", // v5.4.11
        "symfony/twig-bundle": "5.4.*", // v5.4.8
        "symfony/ux-live-component": "^2.x-dev", // 2.x-dev
        "symfony/ux-twig-component": "^2.x-dev", // 2.x-dev
        "symfony/validator": "5.4.*", // v5.4.14
        "symfony/webpack-encore-bundle": "^1.15", // v1.16.0
        "symfony/yaml": "5.4.*", // v5.4.14
        "twig/extra-bundle": "^2.12|^3.0", // v3.4.0
        "twig/twig": "^2.12|^3.0" // v3.4.3
    "require-dev": {
        "doctrine/doctrine-fixtures-bundle": "^3.4", // 3.4.2
        "symfony/debug-bundle": "5.4.*", // v5.4.11
        "symfony/maker-bundle": "^1.47", // v1.47.0
        "symfony/stopwatch": "5.4.*", // v5.4.13
        "symfony/web-profiler-bundle": "5.4.*", // v5.4.14
        "zenstruck/foundry": "^1.22" // v1.22.1