# CollectImportedDependenciesAttribute

> Use this method attribute to specify which methods declare dependancies on imported assets. The methods are called by AssetDatabase during import.

## Definition

* **Type:** Class
* **Namespace:** [UnityEditor.AssetImporters](/engine/6000.6/script-reference/unityeditor/assetimporters.md)
* **Assembly:** UnityEditor.CoreModule
* **Inherits from:** [Attribute](https://learn.microsoft.com/dotnet/api/system.attribute)

```csharp
[AttributeUsage(AttributeTargets.Method, Inherited = false, AllowMultiple = true)]
public class CollectImportedDependenciesAttribute : Attribute
```

## Remarks

The AssetDatabase imports the dependencies declared in methods with this attribute before importing the dependent assets. This also re-imports the dependent asset whenever the dependency asset changes. Use this declared dependency to safely load dependancies in [AssetPostprocessor](/engine/6000.6/script-reference/unityeditor/assetpostprocessor.md) callbacks.

This example shows how you can declare a dependency between two prefabs imported by the [ModelImporter](/engine/6000.6/script-reference/unityeditor/modelimporter.md) and use them in an AssetPostprocessor.

```csharp
using UnityEditor;
using UnityEditor.AssetImporters;
using UnityEngine;

public class ProceduralParentPostprocessor : AssetPostprocessor
{
    private const string s_DependentPath = "Assets/ProceduralPrefab.fbx";
    private const string s_DependencyPath = "Assets/DependencyPrefab.fbx";

    [CollectImportedDependencies(typeof(ModelImporter), 1)]
    public static string[] CollectImportedDependenciesForModelImporter(string assetPath)
    {
        if (assetPath.Equals(s_DependentPath))
            return new[] { s_DependencyPath };

        return null;
    }

    void OnPostprocessMeshHierarchy(GameObject root)
    {
        if (root.name == "ProceduralPrefabRoot")
        {
            // Add a new child game object
            var go = AssetDatabase.LoadMainAssetAtPath(s_DependencyPath) as GameObject;
            Object.Instantiate(go, root.transform, true);
        }
    }
}
```

**Note:** The attribute supports only native importer types with [AssetPostprocessor](/engine/6000.6/script-reference/unityeditor/assetpostprocessor.md) callbacks: [ModelImporter](/engine/6000.6/script-reference/unityeditor/modelimporter.md), [TextureImporter](/engine/6000.6/script-reference/unityeditor/textureimporter.md), [AudioImporter](/engine/6000.6/script-reference/unityeditor/audioimporter.md), and [SpeedTreeImporter](/engine/6000.6/script-reference/unityeditor/speedtreeimporter.md).

## Constructors

| Constructor                                                                                                                                                                | Description                                                                                 |
| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------- |
| [CollectImportedDependenciesAttribute(System.Type,System.UInt32)](/engine/6000.6/script-reference/unityeditor/assetimporters/collectimporteddependenciesattribute/ctor.md) | Use the CollectImportedDependencies attribute to declare getters for imported dependencies. |

## Properties

| Property                                                                                                                        | Description                                                                    |
| ------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------ |
| [importerType](/engine/6000.6/script-reference/unityeditor/assetimporters/collectimporteddependenciesattribute/importertype.md) | The type of the importer for which the imported dependency getter is declared. |
| [version](/engine/6000.6/script-reference/unityeditor/assetimporters/collectimporteddependenciesattribute/version.md)           | The version of the imported dependency getter.                                 |

## Inheritance

**Inherited Members:**

* [Attribute.GetCustomAttributes(MemberInfo, Type)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattributes#system-attribute-getcustomattributes\(system-reflection-memberinfo-system-type\))
* [Attribute.GetCustomAttributes(MemberInfo, Type, bool)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattributes#system-attribute-getcustomattributes\(system-reflection-memberinfo-system-type-system-boolean\))
* [Attribute.GetCustomAttributes(MemberInfo)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattributes#system-attribute-getcustomattributes\(system-reflection-memberinfo\))
* [Attribute.GetCustomAttributes(MemberInfo, bool)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattributes#system-attribute-getcustomattributes\(system-reflection-memberinfo-system-boolean\))
* [Attribute.IsDefined(MemberInfo, Type)](https://learn.microsoft.com/dotnet/api/system.attribute.isdefined#system-attribute-isdefined\(system-reflection-memberinfo-system-type\))
* [Attribute.IsDefined(MemberInfo, Type, bool)](https://learn.microsoft.com/dotnet/api/system.attribute.isdefined#system-attribute-isdefined\(system-reflection-memberinfo-system-type-system-boolean\))
* [Attribute.GetCustomAttribute(MemberInfo, Type)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattribute#system-attribute-getcustomattribute\(system-reflection-memberinfo-system-type\))
* [Attribute.GetCustomAttribute(MemberInfo, Type, bool)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattribute#system-attribute-getcustomattribute\(system-reflection-memberinfo-system-type-system-boolean\))
* [Attribute.GetCustomAttributes(ParameterInfo)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattributes#system-attribute-getcustomattributes\(system-reflection-parameterinfo\))
* [Attribute.GetCustomAttributes(ParameterInfo, Type)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattributes#system-attribute-getcustomattributes\(system-reflection-parameterinfo-system-type\))
* [Attribute.GetCustomAttributes(ParameterInfo, Type, bool)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattributes#system-attribute-getcustomattributes\(system-reflection-parameterinfo-system-type-system-boolean\))
* [Attribute.GetCustomAttributes(ParameterInfo, bool)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattributes#system-attribute-getcustomattributes\(system-reflection-parameterinfo-system-boolean\))
* [Attribute.IsDefined(ParameterInfo, Type)](https://learn.microsoft.com/dotnet/api/system.attribute.isdefined#system-attribute-isdefined\(system-reflection-parameterinfo-system-type\))
* [Attribute.IsDefined(ParameterInfo, Type, bool)](https://learn.microsoft.com/dotnet/api/system.attribute.isdefined#system-attribute-isdefined\(system-reflection-parameterinfo-system-type-system-boolean\))
* [Attribute.GetCustomAttribute(ParameterInfo, Type)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattribute#system-attribute-getcustomattribute\(system-reflection-parameterinfo-system-type\))
* [Attribute.GetCustomAttribute(ParameterInfo, Type, bool)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattribute#system-attribute-getcustomattribute\(system-reflection-parameterinfo-system-type-system-boolean\))
* [Attribute.GetCustomAttributes(Module, Type)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattributes#system-attribute-getcustomattributes\(system-reflection-module-system-type\))
* [Attribute.GetCustomAttributes(Module)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattributes#system-attribute-getcustomattributes\(system-reflection-module\))
* [Attribute.GetCustomAttributes(Module, bool)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattributes#system-attribute-getcustomattributes\(system-reflection-module-system-boolean\))
* [Attribute.GetCustomAttributes(Module, Type, bool)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattributes#system-attribute-getcustomattributes\(system-reflection-module-system-type-system-boolean\))
* [Attribute.IsDefined(Module, Type)](https://learn.microsoft.com/dotnet/api/system.attribute.isdefined#system-attribute-isdefined\(system-reflection-module-system-type\))
* [Attribute.IsDefined(Module, Type, bool)](https://learn.microsoft.com/dotnet/api/system.attribute.isdefined#system-attribute-isdefined\(system-reflection-module-system-type-system-boolean\))
* [Attribute.GetCustomAttribute(Module, Type)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattribute#system-attribute-getcustomattribute\(system-reflection-module-system-type\))
* [Attribute.GetCustomAttribute(Module, Type, bool)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattribute#system-attribute-getcustomattribute\(system-reflection-module-system-type-system-boolean\))
* [Attribute.GetCustomAttributes(Assembly, Type)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattributes#system-attribute-getcustomattributes\(system-reflection-assembly-system-type\))
* [Attribute.GetCustomAttributes(Assembly, Type, bool)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattributes#system-attribute-getcustomattributes\(system-reflection-assembly-system-type-system-boolean\))
* [Attribute.GetCustomAttributes(Assembly)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattributes#system-attribute-getcustomattributes\(system-reflection-assembly\))
* [Attribute.GetCustomAttributes(Assembly, bool)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattributes#system-attribute-getcustomattributes\(system-reflection-assembly-system-boolean\))
* [Attribute.IsDefined(Assembly, Type)](https://learn.microsoft.com/dotnet/api/system.attribute.isdefined#system-attribute-isdefined\(system-reflection-assembly-system-type\))
* [Attribute.IsDefined(Assembly, Type, bool)](https://learn.microsoft.com/dotnet/api/system.attribute.isdefined#system-attribute-isdefined\(system-reflection-assembly-system-type-system-boolean\))
* [Attribute.GetCustomAttribute(Assembly, Type)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattribute#system-attribute-getcustomattribute\(system-reflection-assembly-system-type\))
* [Attribute.GetCustomAttribute(Assembly, Type, bool)](https://learn.microsoft.com/dotnet/api/system.attribute.getcustomattribute#system-attribute-getcustomattribute\(system-reflection-assembly-system-type-system-boolean\))
* [Attribute.Equals(Object)](https://learn.microsoft.com/dotnet/api/system.attribute.equals)
* [Attribute.GetHashCode()](https://learn.microsoft.com/dotnet/api/system.attribute.gethashcode)
* [Attribute.Match(Object)](https://learn.microsoft.com/dotnet/api/system.attribute.match)
* [Attribute.IsDefaultAttribute()](https://learn.microsoft.com/dotnet/api/system.attribute.isdefaultattribute)
* [Attribute.TypeId()](https://learn.microsoft.com/dotnet/api/system.attribute.typeid)