AWS Documentation » Amazon Lumberyard » User Guide » Writing Lua Scripts for the Component Entity System » Network Binding

Network Binding

For network binding features to function, you must have a Creating a NetBindable Component.

Properties

You can configure networking binding for properties by adding the netSynched table to the description of the variable inside of the Properties table.

local ExampleScript = {
    Properties = {
        Speed = {
            default = 0,   -- Supports numbers, strings, booleans, and nils for net bindings.
            min = 0,
            max = 100,
            step = 1,
            description = "Speed in m/s for the ...",
 
            -- If this table is missing, it is assumed the value is not networked.
            netSynched =
            {
                -- Optional fields
                OnNewValue = <function> -- OnNewValue is called whenever the property has a
                                        -- new value. OnNewValue accepts one parameter,which
                                        -- is the entity table for the instance that changed.
 
                -- The following flags are mainly here for debugging and profiling convenience.
                Enabled = true          -- Controls whether the field is network enabled. If 
                                        -- missing, assumes true.
                ForceIndex = [1..32]    -- Profiling helper tool to force a property to use a
                                        -- specific DataSet to make understanding what data is 
                                        -- being used where easier.
            }``
        }
    }
}
return ExampleScript

After you add networking to a property, any changes to the property are reflected across the network.

RPCs

Exposing RPCs to scripts involves creating a new table inside of the component table, but outside of the properties table, as shown in the following example.

local ExampleScript = {
    Properties = {
        -- ...
    },
  
    -- Table of remote procedure calls (RPCs) that the script wants to implement.
    NetRPCs =
    {
        RPCNoParam = {
            OnMaster = <function> -- The function to be called on the Master Script.
                                  -- The function should return a bool value that 
                                  -- indicates whether or not proxy components can 
                                  -- execute the RPC on themselves. Required.
            OnProxy = <function>  -- The function to be called on the Proxy Script. 
                                  -- This function is optional and can be excluded if 
                                  -- the master never allows proxies to execute the function call.
        }
    }
}
 
return ExampleScript

You can invoke the RPC just like any other function. There is no need to specify the OnMaster/OnProxy from the calling script. For example, you can call RPCs as in the following example.

self.NetRPCs.RPCNoParam()
self.NetRPCs.RPCParam(1.0)