Construction Methods

Details

Common
From Factory
From Unity Prefab
From Unity Hierarchy
From Unity Resources
From Resolve

Common

FromNew - Create via the C# new operator. This is the default if no construction method is specified.
```
// These are both the same
Container.Bind<Foo>();
Container.Bind<Foo>().FromNew();
```

FromInstance - Add a given instance to the container. Note that the given instance will not be injected in this case. If you also want your instance to be injected at startup, see QueueForInject

Container.Bind<Foo>().FromInstance(new Foo());

// You can also use this short hand which just takes ContractType from the parameter type
Container.BindInstance(new Foo());

// This is also what you would typically use for primitive types
Container.BindInstance(5.13f);
Container.BindInstance("foo");

// Or, if you have many instances, you can use BindInstances
Container.BindInstances(5.13f, "foo", new Foo());

FromMethod - Create via a custom method

Container.Bind<Foo>().FromMethod(SomeMethod);

Foo SomeMethod(InjectContext context)
{
    ...
    return new Foo();
}

FromMethodMultiple - Same as FromMethod except allows returning multiple instances at once (or zero).

Container.Bind<Foo>().FromMethodMultiple(GetFoos);

IEnumerable<Foo> GetFoos(InjectContext context)
{
    ...
    return new Foo[]
    {
        new Foo(),
        new Foo(),
        new Foo(),
    }
}

From Factory

FromFactory - Create instance using a custom factory class. This construction method is similar to FromMethod except can be cleaner in cases where the logic is more complicated or requires dependencies (since the factory itself can have dependencies injected)
```
class FooFactory : IFactory<Foo>
{
    public Foo Create()
    {
        // ...
        return new Foo();
    }
}

Container.Bind<Foo>().FromFactory<FooFactory>()
```

FromIFactory - Create instance using a custom factory class. This is a more generic and more powerful alternative to FromFactory, because you can use any kind of construction method you want for your custom factory (unlike FromFactory which assumes FromNew().AsCached())

For example, you could use a factory that is a scriptable object like this:

class FooFactory : ScriptableObject, IFactory<Foo>
{
    public Foo Create()
    {
        // ...
        return new Foo();
    }
}

Container.Bind<Foo>().FromIFactory(x => x.To<FooFactory>().FromScriptableObjectResource("FooFactory")).AsSingle();

Or, you might want to have your custom factory be placed in a subcontainer like this:

public class FooFactory : IFactory<Foo>
{
    public Foo Create()
    {
        return new Foo();
    }
}

public override void InstallBindings()
{
    Container.Bind<Foo>().FromIFactory(x => x.To<FooFactory>().FromSubContainerResolve().ByMethod(InstallFooFactory)).AsSingle();
}

void InstallFooFactory(DiContainer subContainer)
{
    subContainer.Bind<FooFactory>().AsSingle();
}

Also note that the following two lines are equivalent:

Container.Bind<Foo>().FromFactory<FooFactory>().AsSingle();
Container.Bind<Foo>().FromIFactory(x => x.To<FooFactory>().AsCached()).AsSingle();

From Prefab

FromComponentInNewPrefab - Instantiate the given prefab as a new game object, inject any MonoBehaviour's on it, and then search the result for type ResultType in a similar way that GetComponentInChildren works
```
Container.Bind<Foo>().FromComponentInNewPrefab(somePrefab);
```
ResultType must either be an interface or derive from UnityEngine.MonoBehaviour / UnityEngine.Component in this case

Note that if there are multiple matches for ResultType on the prefab it will only match the first one encountered just like how GetComponentInChildren works. So if you are binding a prefab and there isn't a specific MonoBehaviour/Component that you want to bind to, you can just choose Transform and it will match the root of the prefab.
FromComponentsInNewPrefab - Same as FromComponentInNewPrefab except will match multiple values or zero values. You might use it for example and then inject List<ContractType> somewhere. Can be thought of as similar to GetComponentsInChildren
FromComponentInNewPrefabResource - Instantiate the given prefab (found at the given resource path) as a new game object, inject any MonoBehaviour's on it, and then search the result for type ResultType in a similar way that GetComponentInChildren works (in that it will return the first matching value found)
```
Container.Bind<Foo>().FromComponentInNewPrefabResource("Some/Path/Foo");
```
ResultType must either be an interface or derive from UnityEngine.MonoBehaviour / UnityEngine.Component in this case
FromComponentsInNewPrefabResource - Same as FromComponentInNewPrefab except will match multiple values or zero values. You might use it for example and then inject List<ContractType> somewhere. Can be thought of as similar to GetComponentsInChildren
FromNewComponentOnNewGameObject - Create a new empty game object and then instantiate a new component of the given type on it.
```
Container.Bind<Foo>().FromNewComponentOnNewGameObject();
```
ResultType must derive from UnityEngine.MonoBehaviour / UnityEngine.Component in this case
FromNewComponentOnNewPrefab - Instantiate the given prefab as a new game object and also instantiate a new instance of the given component on the root of the new game object. NOTE: It is not necessary that the prefab contains a copy of the given component.
```
Container.Bind<Foo>().FromNewComponentOnNewPrefab(somePrefab);
```
ResultType must derive from UnityEngine.MonoBehaviour / UnityEngine.Component in this case
FromNewComponentOnNewPrefabResource - Instantiate the given prefab (found at the given resource path) and also instantiate a new instance of the given component on the root of the new game object. NOTE: It is not necessary that the prefab contains a copy of the given component.
```
Container.Bind<Foo>().FromNewComponentOnNewPrefabResource("Some/Path/Foo");
```
ResultType must derive from UnityEngine.MonoBehaviour / UnityEngine.Component in this case

From Unity Hierarchy

FromNewComponentOn - Instantiate a new component of the given type on the given game object
```
Container.Bind<Foo>().FromNewComponentOn(someGameObject);
```
ResultType must derive from UnityEngine.MonoBehaviour / UnityEngine.Component in this case
FromNewComponentSibling - Instantiate a new component of the given on the current transform. The current transform here is taken from the object being injected, which must therefore be a MonoBehaviour derived type.
```
Container.Bind<Foo>().FromNewComponentSibling();
```
Note that if the given component type is already attached to the current transform that this will just return that instead of creating a new component. As a result, this bind statement functions similar to Unity's [RequireComponent] attribute.

ResultType must derive from UnityEngine.MonoBehaviour / UnityEngine.Component in this case

Also note that if a non-MonoBehaviour requests the given type, an exception will be thrown, since there is no current transform in that case.
FromComponentInHierarchy - Look up the component within the scene hierarchy associated with the current context, as well as the hierarchy associated with any parent contexts. Works similar to GetComponentInChildren in that it will return the first matching value found
```
Container.Bind<Foo>().FromComponentInHierarchy().AsSingle();
```
ResultType must either be an interface or derive from UnityEngine.MonoBehaviour / UnityEngine.Component in this case

In the most common case where the context is a SceneContext, this will search the entire scene hierarchy (except any sub-contexts such as GameObjectContext). In other words, when the current context is a scene context, it will behave similar to GameObject.FindObjectsOfType. Note that since this could be a big search, it should be used with caution, just like GameObject.FindObjectsOfType should be used with caution.

In the case where the context is GameObjectContext, it will only search within and underneath the game object root (and any parent contexts).

In the case where the context is ProjectContext, it will only search within the project context prefab
FromComponentsInHierarchy - Same as FromComponentInHierarchy except will match multiple values or zero values. You might use it for example and then inject List<ContractType> somewhere. Can be thought of as similar to GetComponentsInChildren
FromComponentSibling - Look up the given component type by searching over the components that are attached to the current transform. The current transform here is taken from the object being injected, which must therefore be a MonoBehaviour derived type.
```
Container.Bind<Foo>().FromComponentSibling();
```
ResultType must either be an interface or derive from UnityEngine.MonoBehaviour / UnityEngine.Component in this case

Note that if a non-MonoBehaviour requests the given type, an exception will be thrown, since there is no current transform in that case.
FromComponentsSibling - Same as FromComponentSibling except will match multiple values or zero values.
FromComponentInParents - Look up the component by searching the current transform or any parent for the given component type. The current transform here is taken from the object being injected, which must therefore be a MonoBehaviour derived type.
```
Container.Bind<Foo>().FromComponentInParents();
```
ResultType must either be an interface or derive from UnityEngine.MonoBehaviour / UnityEngine.Component in this case

Note that if a non-MonoBehaviour requests the given type, an exception will be thrown, since there is no current transform in that case.
FromComponentsInParents - Same as FromComponentInParents except will match multiple values or zero values. You might use it for example and then inject List<ContractType> somewhere
FromComponentInChildren - Look up the component by searching the current transform or any child transform for the given component type. The current transform here is taken from the object being injected, which must therefore be a MonoBehaviour derived type. Similar to GetComponentInChildren in that it will return the first matching value found
```
Container.Bind<Foo>().FromComponentInChildren();
```
ResultType must either be an interface or derive from UnityEngine.MonoBehaviour / UnityEngine.Component in this case

Note that if a non-MonoBehaviour requests the given type, an exception will be thrown, since there is no current transform in that case.
FromComponentsInChildren - Same as FromComponentInChildren except will match multiple values or zero values. You might use it for example and then inject List<ContractType> somewhere. Can be thought of as similar to GetComponentsInChildren
FromNewComponentOnRoot - Instantiate the given component on the root of the current context. This is most often used with GameObjectContext.
```
Container.Bind<Foo>().FromNewComponentOnRoot();
```
ResultType must derive from UnityEngine.MonoBehaviour / UnityEngine.Component in this case

From Unity Resources

FromResource - Create by calling the Unity3d function Resources.Load for ResultType. This can be used to load any type that Resources.Load can load, such as textures, sounds, prefabs, etc.
```
Container.Bind<Texture>().WithId("Glass").FromResource("Some/Path/Glass");
```
FromResources - Same as FromResource except will match multiple values or zero values. You might use it for example and then inject List<ContractType> somewhere
FromScriptableObjectResource - Bind directly to the scriptable object instance at the given resource path. NOTE: Changes to this value while inside unity editor will be saved persistently. If this is undesirable, use FromNewScriptableObjectResource.
```
public class Foo : ScriptableObject
{
}

Container.Bind<Foo>().FromScriptableObjectResource("Some/Path/Foo");
```
FromNewScriptableObjectResource - Same as FromScriptableObjectResource except it will instantiate a new copy of the given scriptable object resource. This can be useful if you want to have multiple distinct instances of the given scriptable object resource, or if you want to ensure that the saved values for the scriptable object are not affected by changing at runtime.

From Resolve

FromResolve - Get instance by doing another lookup on the container (in other words, calling DiContainer.Resolve<ResultType>()). Note that for this to work, ResultType must be bound in a separate bind statement. This construction method can be especially useful when you want to bind an interface to another interface, as shown in the below example
```
public interface IFoo
{
}

public interface IBar : IFoo
{
}

public class Foo : IBar
{
}

Container.Bind<IFoo>().To<IBar>().FromResolve();
Container.Bind<IBar>().To<Foo>();
```
FromResolveAll - Same as FromResolve except will match multiple values or zero values.
FromResolveGetter<ObjectType> - Get instance from the property of another dependency which is obtained by doing another lookup on the container (in other words, calling DiContainer.Resolve<ObjectType>() and then accessing a value on the returned instance of type ResultType). Note that for this to work, ObjectType must be bound in a separate bind statement.
```
public class Bar
{
}

public class Foo
{
    public Bar GetBar()
    {
        return new Bar();
    }
}

Container.Bind<Foo>();
Container.Bind<Bar>().FromResolveGetter<Foo>(x => x.GetBar());
```
FromResolveAllGetter<ObjectType> - Same as FromResolveGetter except will match multiple values or zero values.
FromSubContainerResolve - Get ResultType by doing a lookup on a subcontainer. Note that for this to work, the sub-container must have a binding for ResultType. This approach can be very powerful, because it allows you to group related dependencies together inside a mini-container, and then expose only certain classes (aka "Facades") to operate on this group of dependencies at a higher level. For more details on using sub-containers, see this section. There are several ways to define the subcontainer:
1. ByNewPrefabMethod - Initialize subcontainer by instantiating a new prefab. Note that unlike ByNewContextPrefab, this bind method does not require that there be a GameObjectContext attached to the prefab. In this case the GameObjectContext is added dynamically and then run with the given installer method.
```
Container.Bind<Foo>().FromSubContainerResolve().ByNewPrefabMethod(MyPrefab, InstallFoo);

void InstallFoo(DiContainer subContainer)
{
    subContainer.Bind<Foo>();
}
```
  Note that instead of passing in a prefab directly, you can also pass in a getter method. For example:
```
Container.Bind<Foo>().FromSubContainerResolve().ByNewPrefabMethod(ChooseFooPrefab, InstallFoo);

UnityEngine.Object ChooseFooPrefab(InjectContext context) {
    return FooPrefabs[Random.Range(0, FooPrefabs.Length)];
}
```
2. ByNewPrefabInstaller - Initialize subcontainer by instantiating a new prefab. Same as ByNewPrefabMethod, except it initializes the dynamically created GameObjectContext with the given installer rather than a method.
```
Container.Bind<Foo>().FromSubContainerResolve().ByNewPrefabInstaller<FooInstaller>(MyPrefab);

class FooInstaller : Installer
{
    public override void InstallBindings()
    {
        Container.Bind<Foo>();
    }
}
```
  Note that instead of passing in a prefab directly, you can also pass in a getter method. For example:
```
Container.Bind<Foo>().FromSubContainerResolve().ByNewPrefabInstaller<FooInstaller>(ChooseFooPrefab);

UnityEngine.Object ChooseFooPrefab(InjectContext context) {
    return FooPrefabs[Random.Range(0, FooPrefabs.Length)];
}
```
3. ByNewPrefabResourceMethod - Initialize subcontainer instantiating a new prefab obtained via Resources.Load. Note that unlike ByNewPrefabResource, this bind method does not require that there be a GameObjectContext attached to the prefab. In this case the GameObjectContext is added dynamically and then run with the given installer method.
```
Container.Bind<Foo>().FromSubContainerResolve().ByNewPrefabResourceMethod("Path/To/MyPrefab", InstallFoo);

void InstallFoo(DiContainer subContainer)
{
    subContainer.Bind<Foo>();
}
```
4. ByNewPrefabResourceInstaller - Initialize subcontainer instantiating a new prefab obtained via Resources.Load. Same as ByNewPrefabResourceMethod, except it initializes the dynamically created GameObjectContext with the given installer rather than a method.
```
Container.Bind<Foo>().FromSubContainerResolve().ByNewPrefabResourceInstaller<FooInstaller>("Path/To/MyPrefab");

class FooInstaller : Installer<FooInstaller>
{
    public override void InstallBindings()
    {
        Container.Bind<Foo>();
    }
}
```
5. ByNewGameObjectInstaller - Initialize subcontainer by instantiating a empty game object, attaching GameObjectContext, and then installing using the given installer. This approach is very similar to ByInstaller except has the following advantages:
  - Any ITickable, IInitializable, IDisposable, etc. bindings will be called properly
  - Any new game objects that are instantiated inside the subcontainer will be parented underneath the game object context object
  - You can destroy the subcontainer by just destroying the game object context game object
6. ByNewGameObjectMethod - Same as ByNewGameObjectInstaller except the subcontainer is initialized based on the given method rather than an installer type.
7. ByMethod - Initialize the subcontainer by using a method.
```
Container.Bind<Foo>().FromSubContainerResolve().ByMethod(InstallFooFacade);

void InstallFooFacade(DiContainer subContainer)
{
    subContainer.Bind<Foo>();
}
```
  Note that when using ByMethod, if you want to use zenject interfaces such as ITickable, IInitializable, IDisposable inside your subcontainer then you have to also use the WithKernel bind method like this:
```
Container.Bind<Foo>().FromSubContainerResolve().ByMethod(InstallFooFacade).WithKernel();

void InstallFooFacade(DiContainer subContainer)
{
    subContainer.Bind<Foo>();
    subContainer.Bind<ITickable>().To<Bar>();
}
```
8. ByInstaller - Initialize the subcontainer by using a class derived from Installer. This can be a cleaner and less error-prone alternative than ByMethod, especially if you need to inject data into the installer itself. Less error prone because when using ByMethod it is common to accidentally use Container instead of subContainer in your method.
```
Container.Bind<Foo>().FromSubContainerResolve().ByInstaller<FooFacadeInstaller>();

class FooFacadeInstaller : Installer
{
    public override void InstallBindings()
    {
        Container.Bind<Foo>();
    }
}
```
  Note that when using ByInstaller, if you want to use zenject interfaces such as ITickable, IInitializable, IDisposable inside your subcontainer then you have to also use the WithKernel bind method like this:
```
Container.Bind<Foo>().FromSubContainerResolve().ByInstaller<FooFacadeInstaller>().WithKernel();
```
9. ByNewContextPrefab - Initialize subcontainer by instantiating a new prefab. Note that the prefab must contain a GameObjectContext component attached to the root game object. For details on GameObjectContext see this section.
```
Container.Bind<Foo>().FromSubContainerResolve().ByNewContextPrefab(MyPrefab);

// Assuming here that this installer is added to the GameObjectContext at the root
// of the prefab.  You could also use a ZenjectBinding in the case where Foo is a MonoBehaviour
class FooFacadeInstaller : MonoInstaller
{
    public override void InstallBindings()
    {
        Container.Bind<Foo>();
    }
}
```
10. ByNewContextPrefabResource - Initialize subcontainer instantiating a new prefab obtained via Resources.Load. Note that the prefab must contain a GameObjectContext component attached to the root game object.
```
Container.Bind<Foo>().FromSubContainerResolve().ByNewContextPrefabResource("Path/To/MyPrefab");
```
11. ByInstance - Initialize the subcontainer by directly using a given instance of DiContainer that you provide yourself. This is only useful in some rare edge cases.
FromSubContainerResolveAll - Same as FromSubContainerResolve except will match multiple values or zero values.

Construction Methods - mariaheine/Zenject-But-Wiki GitHub Wiki