AddDebugHook

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This function allows tracing of MTA functions and events. It should only be used when debugging scripts as it may degrade script performance.

Debug hooks are not recursive, so functions and events triggered inside the hook callback will not be traced.

Syntax

bool addDebugHook( string hookType, function callbackFunction[, table nameList ] )

Required Arguments

  • hookType: The type of hook to add. This can be:
    • preEvent
    • postEvent
    • preFunction
    • postFunction
  • callbackFunction : The function to call
FROM VERSION 1.5.2 r7967 ONWARDS
  • Returning the string "skip" from the callback function will cause the original function/event to be skipped

Optional Arguments

  • nameList: Table of strings for restricting which functions and events the hook will be triggered on
FROM VERSION 1.5.2 r7967 ONWARDS
  • addDebugHook and removeDebugHook will only be hooked if they are specified in the name list

Returns

Returns true if the hook was successfully added, or false otherwise.

Callback parameters

string preFunction( resource sourceResource, string functionName, bool isAllowedByACL, string luaFilename, int luaLineNumber, functionArguments )
       postFunction( resource sourceResource, string functionName, bool isAllowedByACL, string luaFilename, int luaLineNumber, functionArguments )
string preEvent( resource sourceResource, string eventName, element eventSource, element eventClient, string luaFilename, int luaLineNumber, eventArguments )
       postEvent( resource sourceResource, string eventName, element eventSource, element eventClient, string luaFilename, int luaLineNumber, eventArguments )

Example

This example will dump info about all triggered events:

function onPreEvent( sourceResource, eventName, eventSource, eventClient, luaFilename, luaLineNumber, ... )
    local args = { ... }
    local srctype = eventSource and getElementType(eventSource)
    local resname = sourceResource and getResourceName(sourceResource)
    local plrname = eventClient and getPlayerName(eventClient)
    outputDebugString( "preEvent"
        .. " " .. tostring(resname)
        .. " " .. tostring(eventName)
        .. " source:" .. tostring(srctype)
        .. " player:" .. tostring(plrname)
        .. " file:" .. tostring(luaFilename)
        .. "(" .. tostring(luaLineNumber) .. ")"
        .. " numArgs:" .. tostring(#args)
        .. " arg1:" .. tostring(args[1])
        )
end
addDebugHook( "preEvent", onPreEvent )

This example will dump info about all called MTA functions:

function onPreFunction( sourceResource, functionName, isAllowedByACL, luaFilename, luaLineNumber, ... )
    local args = { ... }
    local resname = sourceResource and getResourceName(sourceResource)
    outputDebugString( "preFunction"
        .. " " .. tostring(resname)
        .. " " .. tostring(functionName)
        .. " allowed:" .. tostring(isAllowedByACL)
        .. " file:" .. tostring(luaFilename)
        .. "(" .. tostring(luaLineNumber) .. ")"
        .. " numArgs:" .. tostring(#args)
        .. " arg1:" .. tostring(args[1])
        )
end
addDebugHook( "preFunction", onPreFunction)

This example adds a hook which will only be triggered for the named functions

addDebugHook( "preFunction", onPreFunction, {"setElementPosition","loadstring"} )


FROM VERSION 1.5.2 r7967 ONWARDS

This example shows how to disable addDebugHook

addDebugHook( "preFunction", onPreFunction, {"addDebugHook"} )
function onPreFunction( sourceResource, functionName, isAllowedByACL, luaFilename, luaLineNumber, ... )
    return "skip"
end

Changelog

Version Description
1.3.5-9.06054 Added clientside
1.3.5-9.06142 Added option to restrict to specified functions and events
1.5.2-9.07957 Added option to skip original function/event
Added ability to hook addDebugHook and removeDebugHook

Requirements

Minimum supported server 1.3.4-9.05939
Minimum supported client 1.3.5-9.06054
Note: Using this function requires the resource to have the above minimum version declared in the meta.xml <min_mta_version> section. e.g. <min_mta_version server="1.3.4-9.05939" client="1.3.5-9.06054" />

See Also