Hooking in

Comments

• Rio Join Date: 2005-01-28 Member: 38716Members

  March 2013 edited March 2013

  Hooking is just a fancy name for overwriting already defined Lua functions, extend them and call the original functions again. Lua functions can be assigned to variables and can also be simply redefined. That's why you can do something like this:
  

  // NS2 function we want to hook (this is just for the example, you don't need to specify the function)
  function GetFriendlyFire()
  [...]
  end
  
  // Hook the function and assign it to a variable called oldGetFriendlyFire so we can still call it later
  local oldGetFriendlyFire = GetFriendlyFire
  // Now you just need to redeclare the original function
  function GetFriendlyFire()
     // ... and call the original function again (if the function had parameters, you can just pass them)
     oldGetFriendlyFire()
  
     // new code here
  end
  

  
  If you want to hook into a table method, it pretty much looks the same:
  

  // NS2 method we want to hook
  function NS2Gamerules:CheckGameEnd()
  [...]
  end
  
  // Assign the method to a variable (notice the period instead of the colon)
  local ns2GamerulesCheckGameEnd = NS2Gamerules.CheckGameEnd
  // Redeclare the method
  function NS2Gamerules:CheckGameEnd()
     // ... and call the old method with the current table!
     ns2GamerulesCheckGameEnd(self)
  
     // new code here
  end
  

  
  That's how you would extend a function. If you want to overwrite it, just don't call the original function.
  You might hear the terms pre- and post-hooks, which define where you call the original function. Pre-hooks call the original function after your additional code and post-hooks call the original function before your additional code (like in the example above).
  

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• Sethbeastalan Join Date: 2011-05-05 Member: 97360Members

  March 2013

  Thanks so much for the fast response.

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