Maximum recursion getting shared service - dependency-injection

I have defined two classes (Environment and ConfigurationReader). Both are registered as shared dependencies.
The Environment class tries get the current environment, but for this, needs read a configuration file via ConfigurationReader.
The sequence diagram is:
The classes are:
class Environment
{
...
public function resolve()
{
$config = DI::getDefault()->getCfg();
$config->getValue('pepe', 'db_name');
}
...
}
class ConfigurationReader
{
...
public function getValue($aConfig, $aKey)
{
$path = $this->getFile($aConfig);
}
protected function getFile($aConfig)
{
$env = DI::getDefault()->getEnv();
$path = 'config/' . $env->getShortName() . '/' . $aConfig . '.yml';
return $path;
}
...
}
And are registered and created in the index.php:
...
$di = new FactoryDefault();
$di->setShared('env', function() use ($di) {
$env = new Services\Environment($di);
$env->resolve();
return $env;
});
$di->setShared('cfg', function() use ($di) {
return new Services\ConfigurationReader($di);
});
$di->getShared('cfg');
$di->getShared('env');
...
So, PHP crash at $config = DI::getDefault()->getCfg(); and says:
PHP Fatal error: Maximum recursion depth exceeded
Any ideas ?

A couple remarks
You're passing the di to the constructor, but end up getting it statically (DI::getDefault())
regarding the infinite loop, it's because cfg needs env who needs cfg who needs env etc.....
To have the framework automatically injecting the DI into your service you should either implement InjectionAwareInterface (https://docs.phalconphp.com/en/latest/reference/di.html#automatic-injecting-of-the-di-itself) or
extend the Component class (If you need event management too, use Plugin instead of Component ). Have a look at this discussion : https://forum.phalconphp.com/discussion/383/plugin-vs-component-what-s-the-difference-
Regarding your use case, you don't give enough context for an exhaustive answer, but I think you could simplify it as:
ConfigService: Unless you use configs from different env namespaces, you should pass the value of $env->getShortName() value to the service constructor (without getting it from the env service). In our apps the env is determined by nginx based on the domain name or other parameters and passed as an environment variable to php. Also, if you don't have hundreds of config files, and your app heavily relies on them, you should read and parse them once on instantiation and store the configs in the service (as associative array, config objects, or whatever you prefer). Add some cache layer to avoid wasting resource parsing all your files on each request. Phalcons provide The Config component to do so. It comes with file adapters (only ini and associative array format but you could easily implement your own yml adapter). If most of your app config relies on configurable values, that will probably be the first component you want to instantiate (or at least declare in the di). It shouldn't dependencies to other services.
EnvService: You can access your config values by calling the config service (If you have it to extend Component, you can do something like $this->cfg->getValue($key)).

Related

Service Dependencies in NestJS

I have many endpoints in my app:
/Route1
/Route2
...
/Route99
In a number of these routes, there is some common functionality such as getting specific data from one source such as a local file, or another resource such as a No SQL database or external HTTP endpoint. My problem is that these services need to have a service dependency themselves, and I am not sure that how I have currently done it is the best way to do it in NestJS.
Route1Service - Read a file of data, and return it. This uses the FileSystemService() to wrap all the error handling, different data types, path checking etc., of the NodeJS fs module. The Route1Service then returns this to the Route1Controller
#Injectable()
export class Route1Service {
private FS_:FileSystemService; // defined here instead of constructor, as I do not know how to set it in the constructor via NestJS, or if this is even the best way.
// constructor(private FS_: FileSystemService) { }
// Since I do not set it in the constructor
public DataServiceDI(FsService:FileSystemService):void {
this.FS_ = FsService;
}
public GetData(): string {
const Data:string = this.FS_.ReadLocalFile('a.txt');
return Data;
}
}
Route99Service might do the same thing, but with a different file (b.txt)
#Injectable()
export class Route99Service {
private FS_:FileSystemService;
public DataServiceDI(FsService:FileSystemService):void {
this.FS_ = FsService;
}
public GetData(): string {
const Data:string = this.FS_.ReadLocalFile('b.txt');
return Data;
}
}
This is a contrived example to illustrate my issue. Obviously a basic RouteService could be used, and pass the file name, but I am trying to illustrate the dependent service. I do not know how to define the module(s) to use this dependent service or if I should be doing it this way.
What I have been doing for my definition:
#Module({
controllers: [Route1Controller],
providers: [Route1Service, FileSystemService],
})
export class Route1Module {}
The controller than has the constructor with both Services:
#Controller('route1')
export class Route1Controller
constructor(
private Route1_: Route1Service,
private FsSystem_: FileSystemService
) { }
Now that my controller has the FsSystem service as a separate entity, I need to add a method on my Route1Service, DataServiceDI(), to allow me to pass the FileSystemService as a reference. Then my service can use this service to access the file system.
My question comes down to, is this the best practice for this sort of thing? Ultimately, in my code, these services (FileSystemService, NoSqlService) extend a common service type, so that all my services can have this DataServiceDI() in then (they extend a base service with this definition).
Is this the best approach for longer term maintainability? Is there an easier way to simply inject the proper service into my Route1Service so it is injected by NestJS, and I do not have to do the DI each time?
The current method works for me to be able to simply test the service, since I can easily mock the FileSystemServie, NoSqlService, etc., and then inject the mock.

cdk call CfnBucket (first level) from IBucket refernce

my objective is to call a first level cdk command starting from an interface: IBucket.
I can get the bucket reference starting from this:
const sourceBucket = props.glueTable.bucket;
Afterwords, I need to call:
cfnBucket.replicationConfiguration = {
The procedure is exactly as for the script below:
https://github.com/rogerchi/cdk-s3-bucketreplication/blob/main/src/index.ts
But, as you can see, this script requires:
readonly sourceBucket: s3.Bucket;
Since it is needed to call:
const sourceAccount = cdk.Stack.of(props.sourceBucket).account;
Finally, are there really no other ways to call a cloudformation level 1 command starting from a reference?
It looks odd.
Thank you in advance
Marco
There is an example on exactly this in the aws docs:
If a Construct is missing a feature or you are trying to work around an issue, you can modify the CFN Resource that is encapsulated by the Construct.
All Constructs contain within them the corresponding CFN Resource. For example, the high-level Bucket construct wraps the low-level CfnBucket construct. Because the CfnBucket corresponds directly to the AWS CloudFormation resource, it exposes all features that are available through AWS CloudFormation.
The basic approach to get access to the CFN Resource class is to use construct.node.defaultChild (Python: default_child), cast it to the right type (if necessary), and modify its properties. Again, let's take the example of a Bucket.
// Get the CloudFormation resource
const cfnBucket = bucket.node.defaultChild;
// Change its properties
cfnBucket.analyticsConfiguration = [
{
id: 'Config'
// ...
}
];
From https://docs.aws.amazon.com/cdk/latest/guide/cfn_layer.html
For you, it wouldn't be analyticsconfiguration but bucketreplication of course.

Symfony4 - How to pass a TokenStorageInterface to an EntityListener?

I'm currently working on a project created with api-platform and using Symfony4.
My goal is to be able to use a TokenStorage inside of an EntityListener in order to know the identity of my user.
Unfortunately, I can't find a way to pass a TokenStorageInterface as an argument.
And the autowiring system doesn't seem to work.
services.yaml :
# https://symfony.com/doc/current/best_practices/configuration.html#application-related-configuration
parameters:
locale: 'en'
services:
# default configuration for services in *this* file
_defaults:
autowire: true # Automatically injects dependencies in your services.
autoconfigure: true # Automatically registers your services as commands, event subscribers, etc.
public: false # Allows optimizing the container by removing unused services; this also means
# fetching services directly from the container via $container->get() won't work.
# The best practice is to be explicit about your dependencies anyway.
# makes classes in src/ available to be used as services
# this creates a service per class whose id is the fully-qualified class name
App\:
resource: '../src/*'
exclude: '../src/{Entity,Migrations,Tests}'
# controllers are imported separately to make sure services can be injected
# as action arguments even if you don't extend any base controller class
App\Controller\:
resource: '../src/Controller'
tags: ['controller.service_arguments']
# add more service definitions when explicit configuration is needed
# please note that last definitions always *replace* previous ones
App\EntityListener\KpiDateListener:
public: true,
arguments:
$tokenStorage: '#security.token_storage'
KpiDateListener.php :
<?php
namespace App\EntityListener;
use ApiPlatform\Core\Tests\Fixtures\TestBundle\Manager\UserManager;
use App\Entity\KpiDate;
use App\Entity\StateDate;
use App\Security\User\UserProvider;
use Doctrine\ORM\Event\LifecycleEventArgs;
use Doctrine\ORM\OptimisticLockException;
use Doctrine\ORM\ORMException;
use Psr\Log\LoggerInterface;
use Symfony\Component\Security\Core\Authentication\AuthenticationProviderManager;
use Symfony\Component\Security\Core\Authentication\Token\Storage\TokenStorage;
use Symfony\Component\Security\Core\User\UserInterface;
use Symfony\Component\Security\Core\Authentication\Token\Storage\TokenStorageInterface;
class KpiDateListener
{
private $tokenStorage;
public function __construct(TokenStorageInterface $tokenStorage)
{
$this->tokenStorage = $tokenStorage;
}
public function postPersist(KpiDate $kpiDate, LifecycleEventArgs $args)
{
//Here is my function
}
}
I always have the same error :
Too few arguments to function App\EntityListener\KpiDateListener::__construct(), 0 passed in /srv/api/vendor/doctrine/doctrine-bundle/Mapping/ContainerAwareEntityListenerResolver.php on line 76 and exactly 1 expected
Is there something wrong or missing ?
Thank you
The error message would indicate that autowiring is not enabled for your listener. Autowiring works for services. If your entity listener is not registered as a service, the DI component cannot autowire it, as it does not know about it (and then, instantiating the class will be performed by Doctrine itself).
Try changing to:
App\EntityListener\KpiDateListener:
autowire: true
public: true,
arguments:
$tokenStorage: '#security.token_storage'
tags:
- { name: doctrine.orm.entity_listener }

Dart has a standard way to externalize settings like Java properties?

I'm looking for the right way to externalize the settings in my server Dart application.
In Java the common way would be a property file. Exists something similar in Dart?
You can just use a Dart script for your settings. No point in using a different format if there is no specific reason.
With a simple import you have it available in a typed way.
When the Resource class is implemented, I would just use a JSON file that is deployed with my program.
You could use a global variables, for example:
DB_URL = 'localhost:5432/mydb';
DB_PASS = 'my_pass';
then you could create a different configuration file for every enviroment. For example, for production you could create a production_config.dart which could contains:
loadConfig() {
DB_URL = '123.123.123.123:5432/mydb';
DB_PASS = 'my_prod_pass';
}
Then in your main function you could call production_config.loadConfig if environment is production, for example:
import 'production_config.dart' as prodConfig;
main(List<String> args) {
var ENV = getEnvFromArgs(args);
if(ENV == 'PROD') {
prodConfig.loadConfig();
}
//do other stuff here
}
In that way if you want to change from development to production you only need to pass an argument to your dart program for example:
dart myprogram.dart -env=PROD
The advantages of this approach are that you don't need to create a separate properties, json or yaml file for this, and you don't need to parse them. Furthermore the properties are type-ckecked.
I like putting configuration in a Dart class like what Günter Zöchbauer was talking about, but there is also the option of using the safe_config package. With this you enter the values in a yaml file. Quoting from the docs:
You define a subclass of Configuration with those properties:
class ApplicationConfiguration extends Configuration {
ApplicationConfiguration(String fileName) :
super.fromFile(File(fileName));
int port;
String serverHeader;
}
Your YAML file should contain those two, case-sensitive keys:
port: 8000
serverHeader: booyah/1
To read your configuration file:
var config = new ApplicationConfiguration("config.yaml");
print("${config.port}"); // -> 8000
print("${config.serverHeader}"); // -> "booyah/1"
See also an example from a setup in Aqueduct.
main() {
var env = const String.fromEnvironment("ENV", defaultValue: "local");
print("Env === " + env);
}
Give environment as option while running Dart App
pub serve --port=9002 --define ENV=dev
References:
http://blog.sethladd.com/2013/12/compile-time-dead-code-elimination-with.html
https://github.com/dart-lang/sdk/issues/27998

How can I configure a new IDataBus implementation which has a dependency which needs to be injected in NServiceBus?

I want to replace the default IDataBus implementation (which writes to the filesystem) with one which writes to a db (so it can run on AWS). To this end I have a config extension:
public static class ConfigureSqlServerDataBus
{
public static Configure SqlServerDataBus(this Configure config)
{
var dataBus = new SqlServerDataBus();
config.Configurer.RegisterSingleton<IDataBus>(dataBus);
return config;
}
}
to allow me to configure the bus. But obviously my SqlServerDataBus has a dependency on something which tells it where to write (An IRepository implementation in this case).
Usually I would ask for the dependency through the constructor, but as the config of the service bus is done through the IWantCustomInitialization which will use Activator to create the instance I can't. My understanding is that NServiceBus will use property injection to satisfy the dependencies but it doesn't seem to do this. I have a couple of calls like this after my configuration is done:
Configure
.With()
.DefineEndpointName("SomeName")
.DefaultBuilder()
.DBSubcriptionStorage()
.XmlSerializer()
.SqlServerDataBus()
.MsmqTransport()
.IsTransactional(true)
.UnicastBus()
.LoadMessageHandlers()
.CreateBus()
.Start(() => Configure.Instance.ForInstallationOn<NServiceBus.Installation.Environments.Windows>().Install());
Configure.Instance.Configurer.ConfigureComponent<RepositoryImplementation>(ComponentCallModelEnum.None);
Configure.Instance.Configurer.ConfigureComponent<SqlServerDataBus>(ComponentCallModelEnum.None);
but my setters for the SqlServerDataBus are never called, although the Put method is.
Can someone point out what I'm doing wrong?
You can't change the configuration after the bus has already been started. To move your config calls into the fluent initialization code, use the RunCustomAction method.
Alternatively, you can write a new class which implements INeedInitialization and make your config calls in there. This class will be invoked at the right time.

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