Call Unity C# script functions from JavaScript

You might want to call some Unity code from your JavaScript plug-in or browser code. For example, you might want a JavaScript UI element that triggers a Unity behaviour and needs access to that method.

The recommended way to send data or notifications to the Unity C# script from the browser’s JavaScript is to use the SendMessage function to call methods on GameObjects in your Unity project.

Use the SendMessage helper function

Use SendMessage to call a Unity method of the Unity scripting API from JavaScript code.

There are some restrictions for what sort of methods you can pass. You can only call methods of a GameObject, not general C# methods attached to other objects. Also, only use SendMessage to call a method if one of the following is true:

The method takes no parameters.
The method has one parameter and that parameter is a single string.
The method has one parameter and that parameter is a single number.

Methods with more than one parameter or with parameters of other types can’t be called using SendMessage.

Example SendMessage code

To make the call from a JavaScript plug-in embedded in your project, use the following code:

MyGameInstance.SendMessage(objectName, methodName, value);

objectName is the name of an object in your scene.
methodName is the name of a method in the script, currently attached to that object.
value can be a string, a number, or can be empty.

The following code is a further example that shows each of the types of methods that you can call with different parameters.

MyGameInstance.SendMessage('MyGameObject', 'MyFunction');
MyGameInstance.SendMessage('MyGameObject', 'MyFunction', 5);
MyGameInstance.SendMessage('MyGameObject', 'MyFunction', 'MyString');

To make a call from the global scope of the embedding page, refer to Call JavaScript functions from global scope.

Additional resources

Call JavaScript functions from Unity C# scripts

Call C/C++/C# functions from Unity C# scripts