Dependency injection

Dependency injection is a technique where one object supplies the dependencies of another object. An injection is the passing of a dependency to a dependent object that would use it. Passing the service to the client, rather than allowing a client to build or find the service, is the primitive requirement of the pattern.

This primitive requirement means that using values produced within the class from new or static methods is prohibited. The class should accept values passed in from outside.

The intent behind dependency injection is to decouple objects to the extent that no client code has to be changed simply because an object it depends on needs to be changed to a different one.

Dependency injection is one form of the broader technique of inversion of control. Rather than low level code calling up to high level code, high level code can receive lower level code that it can call down to. This inverts the typical control pattern seen in procedural programming.

Dependency injection supports the dependency inversion principle. The client delegates the responsibility of providing its dependencies to external code (the injector). The client is not allowed to call the injector code. It is the injecting code that constructs the services and calls the client to inject them. This means the client code does not need to know about the injecting code.

There are three common means for a client to accept a dependency injection: setter-, interface and constructor based injection. Setter and constructor injection differ mainly by when they can be used. Interface injection differs in that the dependency is given a chance to control its own injection. All require that separate construction code (the injector) take responsibility for introducing a client and its dependencies to each other.

For example, consider a Car object.

A Car depends on wheels, engine, fuel, battery, etc. to run. Traditionally we define the brand of such dependent objects along with the definition of the Car object.

Without Dependency Injection (DI):

Here, the Car object is responsible for creating the dependent objects.

What if we want to change the type of its dependent object – say Wheel – after the initial IndianWheel() punctures? We need to recreate the Car object with its new dependency say JapaniWheel(), but only the Car manufacturer can do that.

Then what does the Dependency Injection do us for…?

When using dependency injection, objects are given their dependencies at run time rather than compile time (car manufacturing time). So that we can now change the Wheel whenever we want. Here, the dependency (wheel) can be injected into Car at run time.

After using dependency injection:

Here, we are injecting the dependencies (Wheel and Battery) at runtime. Hence the term : Dependency Injection. Malware attack on WordPress

How this malware affect to your website?
This malware added a infected JS to your website pages and because of that whenever you open page it redirects to somewhere else. If antivirus installed on your machine then it will raise notice that website is harmful to your website.
How to prevent?
First reason for this attack is your password. If your password is weak then it will affect to your website very easily.
First way to avoid this type of malware attack, update your password to strong one so that your password never gets hack.
If your website is already affected with this malware then you need to follow below mentioned steps to remove it from your website.
1. You need to find out the affected files so that you can remove this malware from your website, to find out affected files –
1 Disable all your plugin and themes, and reload your website then checkout that affected JS are are loaded or not. If malware not loaded with your page means that any one of your themes or plugins is affected with this malware.
Now the simple way to remove this affected plugins and themes is manually activate one by one plugin and reload webpage and checkout that malware is loaded or not, so that you can easily find out the affected themes and plugins.
2. Another simple way is – this malware update your file type to some suspected file type. So one way is manually find out suspected file types and remove that suspected files.
3. Third way to remove this malware is simply download all your code on your system and scan your root folder with help of good antivirus, it will easily remove infected files from your code base.
4. Sometime this malware affect your WordPress files so in that case you need update your WordPress to latest version.