TransformInternalId

Returns

string A transformation of a given location to a potentially different location used at runtime.

Description

string Addressables.ResourceManager.TransformInternalId(IResourceLocation) is a function that Addressables uses when evaluating internal IDs. You can also manually pass in an IResourceLocation and return an ID based on a transformation function you specify. You can specify the transformation used by the ResourceManager by assigning a Func<IResourceLocation, string> to Addressables.ResourceManager.InternalIdTransformFunc. If no InternalIdTransformFunc is available, then the IResourceLocation.InternalId is returned. IResourceLocation.InternalId is the default location assigned to an IResourceLocation at build time to locate an asset.

Using TransformInternalId grants a fair amount of flexability, especially in regards to remote hosting. Given a single IResourceLocation, you can transform the ID to point towards a server specified at runtime. This is particularly useful if your server IP address changes or to point at different servers for variant purposes.

If Addressables.ResourceManager.InternalIdTransformFunc is not assigned to or is assigned null, then the IResourceLocation.InternalId is used by ResourceManager without passing any transformation.

You do not need to call TransformInternalId manually in order for ResourceManager to use it.

See ResourceManager for its full API documentation.

Code Sample

void Start()
{
    Addressables.ResourceManager.InternalIdTransformFunc = TransformFunc;
}

string TransformFunc(IResourceLocation location)
{
    //Implement a method that gets the base url for a given location
    string baseUrl = GetBaseURL(location);

    //Get the url you want to use to point to your current server
    string currentUrlToUse = GetCurrentURL();

    return location.InternalId.Replace(baseUrl, currentUrlToUse);
}

In the above code sample, GetBaseURL and GetCurrentURL can be any solution you find appropriate for your project; these are not methods implemented in Addressables. The former can be your solution for acquiring the IP/url that was used at build time in the project and will be part of the IResourceLocation.InternalId. The latter can be your solution to get a server that points to your new server IP/url or specifc variant/themed/scaled content.

void Start()
{
    Addressables.ResourceManager.InternalIdTransformFunc = TransformFunc;
}

string TransformFunc(IResourceLocation location)
{
    if(location.PrimaryKey.Contains("background") && MyQualityCheck.Resolution == Res.Low)
        return location.InternalId.Replace("background", "bkg_low");

    return irl.InternalId;
}

This example shows how you could use information provided from the IResourceLocation among other settings to transform the IResourceLocation.InternalId.

These are, of course, only a basic examples of the possibilities provided by assigning a custom implementation to Addressables.ResourceManager.InternalIdTransformFunc.

Pitfalls

If your first loads point to the wrong server, ensure that you assign Addressables.ResourceManager.InternalIdTransformFunc to your desired transform function prior to initiating your operation.