# GetBaseReferenceForConfig(string)

> Gets the base configuration reference GUID for the specified build configuration.

## Definition

* **Type:** Method
* **Namespace:** [UnityEditor.iOS.Xcode](/engine/6000.5/script-reference/unityeditor/ios/xcode.md)
* **Assembly:** UnityEditor.iOS.Extensions.Xcode

```csharp
public string GetBaseReferenceForConfig(string configGuid)
```

### Parameters

**** (\[string]\(https\://learn.microsoft.com/dotnet/api/system.string)): The GUID of the build configuration as returned by [PBXProject.BuildConfigByName](/engine/6000.5/script-reference/unityeditor/ios/xcode/pbxproject/buildconfigbyname.md).

### Returns

| Type                                                           | Description                                                          |
| -------------------------------------------------------------- | -------------------------------------------------------------------- |
| [string](https://learn.microsoft.com/dotnet/api/system.string) | The GUID of the configuration file being used as the base reference. |

### Examples

```csharp
using UnityEngine;
using UnityEditor;
using System.IO;
using UnityEditor.Callbacks;
using UnityEditor.iOS.Xcode;

public class Sample_GetBaseReferenceForConfig  
{
    [PostProcessBuild]
    public static void OnPostprocessBuild(BuildTarget buildTarget, string pathToBuiltProject)
    {

        // Stop processing if build target is not iOS
        if (buildTarget != BuildTarget.iOS)
            return;

        // Initialize PBXProject
        string projectPath = PBXProject.GetPBXProjectPath(pathToBuiltProject);
        PBXProject pbxProject = new PBXProject();
        pbxProject.ReadFromFile(projectPath);

        // Get the main target GUID
        string mainTargetGuid = pbxProject.GetUnityMainTargetGuid();

        // Retrieve the configuration name (this can be "Debug", "Release", or any custom configuration name)
        string configName = "Debug";

        // Get the "Debug" build configuration GUID 
        string configGuid = pbxProject.BuildConfigByName(mainTargetGuid, configName);

        // Use GetBaseReferenceForConfig to get the base reference for the specified configuration
        string baseReference = pbxProject.GetBaseReferenceForConfig(configGuid);

        // Check if baseReference for specified configuration was found
        if (string.IsNullOrEmpty(baseReference))
        {
            Debug.LogError("Unable to find base reference for build configuration: " + configName);
            return;
        }
        else
        {
            // Modify the project using baseReference here
            // In this example we just print the baseReference for "Debug" config in Console
            Debug.Log($"Base reference for {configName} configuration is: {baseReference}");
        }

        // Apply changes to the pbxproj file
        pbxProject.WriteToFile(projectPath);
    }
}
```