noiseinjekt

A simple C++ library that implements dependecy injection.

Prepare compilation

./autogen.sh

Installation

./configure
make
sudo make install
sudo ldconfig /usr/local/lib

Uninstallation

sudo make uninstall

Run

noiseinjekt

Clean all untracked files

git clean -xdf

Use Library

If everything installed fine then pass -lnoiseinjekt parameter in linker, when build your application. Then use it in your app like in example/.

How to use in the code

Step 1: Prepare the wanted `service`.

The object that we want to inject has to implement Service interface. The Service interface can be included from <noiseinjekt/Service.h>.

Then we must create a factory class that creates a new instance of the wanted class. The factory must implement the ServiceFactory interface. Again this interface can be included from <noiseinjekt/Service.h>.

see examples/TestServiceFactory.h and examples/TestService.h for example. The class TestService extends Service. Also the TestServiceFactory extends ServiceFactory.

Step 2: Register `service`.

Then we must register the new service to tha globalAppContext.

Then first we have to create a method that has the specific signature:

void funcExample(int argc, char* argv[])
{
    NoiseInjekt::registerGlobalService<TestServiceFactory>(SINGLETON, "TestService", new TestServiceFactory);
}

inside that function we have to register our new service calling the following

NoiseInjekt::registerGlobalService<TestServiceFactory>(SINGLETON, "TestService", new TestServiceFactory);

this can be included from <noiseinjekt/GlobalAppContext.h>.

The method registerGlobalService is a template method and takes as type the factory class of service that we want to inject. as first param takes the InjectionScope of the service. the scopes can be one of: SINGLETON, REQUEST, START_UP. as second param takes the name of the service. With this name we can access again the wanted service. As thrird param takes a new pointer to the factory that creates the wanted service.

No need to worry about this new pointer to the factory, because is gonna be disposed when GlobalAppContext destroyed, that is in the end of program.

globalAppContext is the context of the whole application. This context initialized first of everything in the main and contains all services.

In order to register the wanted service we must add it in the GlobalAppContextRegistration.cpp file in the src/lib/di/ folder.

Step 3: Injection

After all these we can inject the wanted service.

in the file that we want out service we must include <noiseinjekt/GlobalAppContext.h>. Then we can call the NoiseInjekt::inject< T > method.

This method is a template method. As type takes the wanted service type. As parameter takes the name of the wanted service, as we register in Step 2. And returns a pointer the wanted service.

like this:

TestService* srv = NoiseInjekt::inject<TestService>("TestService");

`InjectionScope`

There are three injection scopes for the application.

`SINGLETON`

This means that the first time that a wanted service will be injected, then it will be initialized with the ServiceFactory. All the rest of the times that will be injected the same reference of the service will be returned.

`REQUEST`

This means that every time that a service will be injected, every time a new instance of this service will be created.

`START_UP`

This means that the service will be intantiated on the start up of the application and inject method will return the same reference of this service.

stolosapo/noise-injekt