<function name="NetworkVarNotify" parent="Entity" type="classfunc"> <description> Creates a callback that will execute when the given network variable changes - that is, when the `Set<name>()` function is run. ⤶ <note>The callback is executed **before** the value is changed, and is called even if the new and old values are the same. This function does not exist on entities in which <page>Entity:InstallDataTable</page> has not been called. By default, this means this function only exists on SENTs (both serverside and clientside) and on players with a <page text="Player Class">Player_Classes</page> (serverside and clientside <page>Global.LocalPlayer</page> only). It's therefore safest to only use this in <page>ENTITY:SetupDataTables</page>.</note>⤶ ⤶ The callback is executed **before** the value is changed, and is called even if the new and old values are the same. This function does not exist on entities in which <page>Entity:InstallDataTable</page> has not been called. ⤶ ⤶ By default, this means this function only exists on SENTs (both serverside and clientside) and on players with a <page text="Player Class">Player_Classes</page> (serverside and clientside <page>Global.LocalPlayer</page> only).⤶ ⤶ It's therefore safest to only use this in <page>ENTITY:SetupDataTables</page>.⤶ <bug request="324">The callback will not be called clientside if the var is changed right after entity spawn.</bug> </description> <realm>Shared</realm> <file line="315-L325">lua/includes/extensions/entity.lua</file> <args> <arg name="name" type="string">Name of variable to track changes of.</arg> <arg name="callback" type="function">The function to call when the variable changes. It is passed 4 arguments:⤶ * <page>Entity</page> entity - Entity whos variable changed.⤶ * <page>string</page> name - Name of changed variable.⤶ * <page>any</page> old - Old/current variable value.⤶ * <page>any</page> new - New variable value that it was set to.</arg> <arg name="callback" type="function">The function to call when the variable changes.⤶ ⤶ <callback>⤶ <arg type="Entity" name="entity">Entity whos variable changed.</arg>⤶ <arg type="string" name="name">Name of changed variable.</arg>⤶ <arg type="any" name="old">Old/current variable value.</arg> <arg type="any" name="new">New variable value that it was set to.</arg>⤶ </callback>⤶ </arg>⤶ </args> </function> <example> <description>Example usage.</description> <code> function ENT:SetupDataTables() self:NetworkVar( "Float", 0, "Amount" ) self:NetworkVar( "Vector", 1, "StartPos" ) self:NetworkVar( "Vector", 2, "EndPos" ) if ( SERVER ) then self:NetworkVarNotify( "EndPos", self.OnVarChanged ) end end function ENT:OnVarChanged( name, old, new ) print( name, old, new ) end </code> <output>Prints variable name, old value and new value whenever SetEndPos function is called.</output> </example>