Need help understanding install of DOMPDF with Composer and Symfony - symfony

Question

I'm having significant amount of troubles trying figure out how to install and use DOMPDF with Composer and Symfony. It is a project written a few years ago and I am completely new to Composer, Symfony and DOMPDF...somebody else told me we were using Composer and Symfony.
I've installed DOMPDF using the puTTy command line interface by:
1. going to the folder where my composer.json is (vendor)
2. running the command "Install dompdf/dompdf" It completed successfully with no errors.
3. Then running the command composer "require dompdf/dompdf" which also completed successfully with no errors.
Then I get lost/confused...
I see instructions that say to edit composer.json with :
{
"require": {
"squizlabs/php_codesniffer": "2.0.*",
}
So here is the new contents of composer.json
{
"require": {
"spipu/html2pdf": "^5.0",
"dompdf/dompdf": "^0.8.1"
}
I've tried using DOMPDF by putting the following line in my PHP code and all I get is a blank page
use Dompdf\Dompdf;
There is also an autoload.php which looks like this:
//autoload.php #generated by Composer
require_once __DIR__ . '/composer/autoload_real.php';
return ComposerAutoloaderInit********************************::getLoader();
Following the rabbit hole, autoload_real.php looks like this:
// autoload_real.php #generated by Composer
class ComposerAutoloaderInit987ec9019a1b2f978bf00ce76684ede0
private static $loader;
public static function loadClassLoader($class)
{
if ('Composer\Autoload\ClassLoader' === $class) {
require __DIR__ . '/ClassLoader.php';
}
}
public static function getLoader()
{
if (null !== self::$loader) {
return self::$loader;
}
spl_autoload_register(array('ComposerAutoloaderInit987ec9019a1b2f978bf00ce76684ede0', 'loadClassLoader'), true, true);
self::$loader = $loader = new \Composer\Autoload\ClassLoader();
spl_autoload_unregister(array('ComposerAutoloaderInit987ec9019a1b2f978bf00ce76684ede0', 'loadClassLoader'));
$useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
if ($useStaticLoader) {
require_once __DIR__ . '/autoload_static.php';
call_user_func(\Composer\Autoload\ComposerStaticInit987ec9019a1b2f978bf00ce76684ede0::getInitializer($loader));
} else {
$map = require __DIR__ . '/autoload_namespaces.php';
foreach ($map as $namespace => $path) {
$loader->set($namespace, $path);
}
$map = require __DIR__ . '/autoload_psr4.php';
foreach ($map as $namespace => $path) {
$loader->setPsr4($namespace, $path);
}
$classMap = require __DIR__ . '/autoload_classmap.php';
if ($classMap) {
$loader->addClassMap($classMap);
}
}
$loader->register(true);
if ($useStaticLoader) {
$includeFiles = Composer\Autoload\ComposerStaticInit987ec9019a1b2f978bf00ce76684ede0::$files;
} else {
$includeFiles = require __DIR__ . '/autoload_files.php';
}
foreach ($includeFiles as $fileIdentifier => $file) {
composerRequire987ec9019a1b2f978bf00ce76684ede0($fileIdentifier, $file);
}
return $loader;
}}function composerRequire987ec9019a1b2f978bf00ce76684ede0($fileIdentifier, $file){if (empty($GLOBALS['__composer_autoload_files'][$fileIdentifier])) {
require $file;$GLOBALS['__composer_autoload_files'][$fileIdentifier] = true;}}
Additionally, I have 14 folders in the vendor file, which I assume are all packages used with Composer, but I don't see them being required in the composer.json file, and, after installing DOMPDF, I don't see a vendor folder for it. I'd like to remove them, but I don't know what is and is not being used.
I've read the "getting started guides" and I still don't know what I've done wrong.
I'm sure I will have a thousand more questions...thank you for your patience.

Answer 1

a) your composer.json file should be in the root of your project directory and not in the vendor directory.
b) just typing the command
composer require dompdf/dompdf
in your project directory should be enough to install the libraries in the vendor directory AND to add the line
"dompdf/dompdf": "^0.8.1"
in your composer.json.
c) Follow instructions on https://github.com/dompdf/dompdf how to use dompdf.
d) In general when working with composer you have to include the vendor/autoload.php file but in the Symfony framework that will already happen in the app/autoload.php.
require 'vendor/autoload.php';
e) dompdf does use namespaces. Little example:
require "../vendor/autoload.php"; // change path if you need to
use Dompdf\Dompdf;
// instantiate and use the dompdf class
$dompdf = new Dompdf();
$dompdf->loadHtml('hello world');
// (Optional) Setup the paper size and orientation
$dompdf->setPaper('A4', 'landscape');
// Render the HTML as PDF
$dompdf->render();
// Output the generated PDF to Browser
$dompdf->stream();
f) Lot of packages that can be installed with composer use other packages too. If you take a look at the composer.json from dompdf you will see that it requires some other packages which composer will automaticly install for you.
[edit]
Your composer.json is in the root directory of your project. Same for your vendor directory. In your vendor directory there will be a composer directory, that is normal. But execute any commands from your root directory. structure:
- [project root] (execute commands here)
|
|- composer.json
|- [vendor]
|
|- [composer]
If you got stuck just delete the whole vendor directory and composer.json file and again use the command
composer require dompdf/dompdf