Custom Systems

The Prysm integration in Unity3D supports multiple systems with custom settings.

Overview

The Prysm CohtmlUISystem component controls some of the behavior of all cohtml.Net.View objects assigned to it. When creating a scene, Prysm will spawn a CohtmlUISystem component in its game object and every CohtmlView will be connected to it unless otherwise specified. If you want to customize the system-related behavior of your CohtmlViews, you can create your custom CohtmlUISystem component and attach any number of CohtmlViews to them. To achieve this, you need to create a game object and add the CohtmlUISystem and CohtmlSystemSettings components to it. You can control these components through the inspector or via script. The cohtml.Net.SystemSettings directly you can customize are:

Below you can see what a system with a custom Resource Handler would look like in the Unity3D Editor.

How to use

To set up a system with a custom Resource handler see the example below. You can assign custom Localization manager and TextTransformation manager in the same way.

The general steps needed are:

  1. Create your custom Resource handler.
  2. Add a System settings component on any GameObject and assign your custom Resource handler to it.
  3. Add a cohtml.Net.UISystem component on any GameObject and assign your System settings component to it.

You can do that via the Unity3D editor or via script.

Using Unity3D editor

  1. Add a CohtmlSystemSettings component to the scene.

  2. Create a script with your custom implementation of the cohtml.Net.IAsyncResourceHandler interface. For this example, we will call it CustomResourceHandler.cs.

  3. Create a MonoBehaviour script that creates your CustomResourceHandler object and attaches it to the ResourceHandler property of the system settings.

    public class CustomSettingsAssigner : MonoBehaviour
{
    public void AssignResourceHandler()
    {
        CohtmlSystemSettings settings = GetComponent<CohtmlSystemSettings>();
        settings.ResourceHandler = new CustomResourceHandler();
    }
}

  4. Attach the CustomSettingsAssigner.cs script to the CohtmlSystemSettings GameObject.

  5. Attach the AssignResourceHandler() method to the first event called On Resource Handler Assign.

  6. Now you can create your own CohtmlUISystem and assign the CohtmlSystemSettings to its properties.

Using custom component

  1. Create a script with your custom implementation of the cohtml.Net.IAsyncResourceHandler interface.

  2. Create a MonoBehaviour script that overrides the UnityEngine.Awake() method. Use it to create a CohtmlSystemSettings component, add your custom Resource Handler to it, then spawn your custom CohtmlUISystem using the CreateNativeUISystem(settings) method.

    public class CustomSettingsAssigner : MonoBehaviour
{
    public void Awake()
    {
        CohtmlSystemSettings settings = gameObject.AddComponent<CohtmlSystemSettings>();
        settings.ResourceHandler = new CustomResourceHandler();

        CohtmlUISystem system = gameObject.AddComponent<CohtmlUISystem>();
        system.CreateNativeUISystem(settings);

        // NOTE: You can start assigning Views to the CohtmlUISystem here
        // i.e. MyView.CohtmlUISystem = system;
    }
}

  3. Now you can add Views to your custom CohtmlUISystem by changing the View.CohtmlUISystem property.

Customizing the CohtmlSystemSettings component

The default behaviors you can override in the SystemSettings from cohtml.Net.SystemSettings are:

Resource handler

The resource handler provides your resources (e.g images, scripts, fonts etc.) to the cohtml.Net.View components. By default, it will load these resources from the UIResources folder or fetch them from the web.

Default Behavior

The UI resources folder in the project is the place from where Prysm loads your pages. When a CohtmlView loads any URL it would try to replace the coui://[host] part of the URL with a specified location until it finds the resource.

By default the only location searched this way will be Assets/StreamingAssets/Cohtml/UIResources. Prysm uses the StreamingAssets folder because it is a special Unity3D location for content that is intended to be included in the built project and can be accessed on all platforms.

For example, when loading the URL coui://UIResources/MyFirstUI/my-page.html, Prysm will search for that file in Assets/StreamingAssets/Cohtml/UIResources/MyFirstUI/my-page.html

Overriding Behaviour

  • You can provide additional locations to be searched for resources inside your project. That functionality comes in handy when you want to store your resources inside other special locations like Application.PersistentDataPath, Application.StreamingAssets or other UI Resources locations inside your project.
  • Prysm keeps a list of Host locations, such as preloaded user images. Every Host holds a list of locations where its resources are stored in. When searching for a resource Prysm will try all locations for the selected host until it is found. If the resource is not found in any of the host’s locations Prysm will show an error message.
  • You can override the default behavior by overriding the HostLocationsMap property.
  • Host preloaded is reserved for preloaded user textures.

Replace resource locations

The general steps needed are:

  1. For the purpose of example, create script ResourceLocationsAssigner.cs, with a method called AssignResourceLocations(). This method will assign the ResourceHandler’s HostLocationsMap property which holds a Dictionary of hosts to Locations map. The host is the key. Value is the location collection.

    public class ResourceLocationsAssigner : MonoBehaviour
{
    public void AssignResourceLocations()
    {
        CohtmlSystemSettings systemSettings = GetComponent<CohtmlSystemSettings>();

        // Create Default or Custom Resource Handler.
        systemSettings.ResourceHandler = new DefaultResourceHandler();
        systemSettings.HostLocationsMap = new Dictionary<string, List<string>>
        {
            // Example how to use Default host and locations. That initialization is not mandatory. 
            {
                DefaultResourceHandler.DefaultHostLocations.Key,
                DefaultResourceHandler.DefaultHostLocations.Value
            },
            {"persistent", new List<string> {Application.persistentDataPath}},

            // Example how to use your custom hosts with collection of locations.
            {"mylocation", new List<string>
            {
                Application.streamingAssetsPath + "/DownloadedPatch",
                Application.streamingAssetsPath + "/MyLocation"
            }}
        };
    }
}

  2. Add an empty GameObject to the Unity3D scene.

  3. Add CohtmlUISystem component to the created GameObject.

  4. Add CohtmlSystemSettings to the created GameObject.

  5. Add ResourceLocationsAssigner.cs to the created GameObject.

  6. Assign your custom Additional Resource Locations to CohtmlSystemSettings component via On Resource Handler Assign.

Localization manager

The Localization manager is used to dynamically translate your User Interface. There is no default Localization manager implementation.

TextTransformation manager

Prysm supports the text-transform CSS property that allows automatic uppercase/lowercase/capitalize transformations of text. There is no default TextTransformation manager implementation, so you need to implement your own.

Debugger settings

You can use the Debugger settings to enable or disable the DevTools Inspector and change its port and enable or disable the Devtools inspector in a built game.

Tips and best practices

  • The CohtmlView.AddMissingWorldViewComponents method adds additional components through Unity3D engine utilities. Adding components at runtime involves extra processing and may lead to increased overhead and inefficiencies compared to pre-configuring these components in advance at runtime. Therefore, you can create your Views and components in advance through the editor. Or ultimately, use a Unity3D prefab, prepared with all the components for the in-world CohtmlView, and instantiate it in the scene. For example:
public GameObject inWorldViewPrefab;
...
CohtmlView cohtmlViewComponent = Instantiate(inWorldViewPrefab).GetComponent<CohtmlView>();
  • It is not necessary to create a CohtmlSystemSettings component for every System you have on the scene. Prysm will assign a default settings component for every system component. Do it only when you want to add a custom implementation.
  • It is not necessary to create CohtmlUISystem components for every CohtmlView instance. You can have multiple CohtmlViews using your custom system at the same time. Having multiple instances of CohtmlUISystem and CohtmlSystemSettings on the same GameObject is not allowed.
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