How to hook this?

[Miiru]

Im trying to hook this function:

function DEFAULT_OBJECTIVE_TRACKER_MODULE:SetStringText(fontString, text, useFullHeight, colorStyle, useHighlight)
	fontString:SetHeight(0);
	fontString:SetText(text);
	local stringHeight = fontString:GetHeight();
	if ( stringHeight > OBJECTIVE_TRACKER_DOUBLE_LINE_HEIGHT and not useFullHeight ) then
		fontString:SetHeight(OBJECTIVE_TRACKER_DOUBLE_LINE_HEIGHT);
		stringHeight = OBJECTIVE_TRACKER_DOUBLE_LINE_HEIGHT;
	end
	colorStyle = colorStyle or OBJECTIVE_TRACKER_COLOR["Normal"];
	if ( useHighlight and colorStyle.reverse ) then
		colorStyle = colorStyle.reverse;
	end
	if ( fontString.colorStyle ~= colorStyle ) then
		fontString:SetTextColor(colorStyle.r, colorStyle.g, colorStyle.b);
		fontString.colorStyle = colorStyle;
	end
	return stringHeight;
end

I tried using

hooksecurefunc(DEFAULT_OBJECTIVE_TRACKER_MODULE,"SetStringText",function(fontString, text, useFullHeight, colorStyle, useHighlight)
	fontString:SetHeight(0);
	fontString:SetText(text);
	local stringHeight = fontString:GetHeight();
	if ( stringHeight > OBJECTIVE_TRACKER_DOUBLE_LINE_HEIGHT and not useFullHeight ) then
		fontString:SetHeight(OBJECTIVE_TRACKER_DOUBLE_LINE_HEIGHT);
		stringHeight = OBJECTIVE_TRACKER_DOUBLE_LINE_HEIGHT;
	end
	colorStyle = colorStyle or OBJECTIVE_TRACKER_COLOR["Normal"];
	if ( useHighlight and colorStyle.reverse ) then
		colorStyle = colorStyle.reverse;
	end
	if ( fontString.colorStyle ~= colorStyle ) then
		fontString:SetTextColor(colorStyle.r, colorStyle.g, colorStyle.b);
		fontString.colorStyle = colorStyle;
	end
	return stringHeight;
end)

I want to alter the fontstrings, but it kept trowing errors at me. What am i doing wrong?

[Choonstertwo]

What error are you getting?

[Miiru]

I am probably doing something very simple wrong.

This is the error message when trying to jsut hook the original function (without altering any code)

Message: Interface\AddOns\miirGui\core.lua:912: attempt to call method 'SetHeight' (a nil value)
Time: 09/21/14 16:51:51
Count: 8
Stack: Interface\AddOns\miirGui\core.lua:912: in function <Interface\AddOns\miirGui\core.lua:911>
[C]: in function `SetStringText'

edit: This is all on PTR.

[Tageshi]

You have to notice a colon between DEFAULT_OBJECTIVE_TRACKER_MODULE and SetStringText.

function DEFAULT_OBJECTIVE_TRACKER_MODULE:SetStringText(fontString, text, useFullHeight, colorStyle, useHighlight)

is same as;

function DEFAULT_OBJECTIVE_TRACKER_MODULE.SetStringText(self, fontString, text, useFullHeight, colorStyle, useHighlight)

thus, try this;

hooksecurefunc(DEFAULT_OBJECTIVE_TRACKER_MODULE,"SetStringText",function(self, fontString, text, useFullHeight, colorStyle, useHighlight)

[sticklord]

Instead of:

hooksecurefunc(DEFAULT_OBJECTIVE_TRACKER_MODULE,"SetStringText",function(fontString, text, useFullHeight, colorStyle, useHighlight)

Use:

hooksecurefunc(DEFAULT_OBJECTIVE_TRACKER_MODULE,"SetStringText",function(_, fontString, text, useFullHeight, colorStyle, useHighlight)

Because i believe the original function has a magical hidden self there.

edit // goodamnit

[Tageshi]

LOL. What a coincidence.

[Miiru]

Originally Posted by sticklord Instead of: hooksecurefunc(DEFAULT_OBJECTIVE_TRACKER_MODULE,"SetStringText",function(fontString, text, useFullHeight, colorStyle, useHighlight) Use: hooksecurefunc(DEFAULT_OBJECTIVE_TRACKER_MODULE,"SetStringText",function(_, fontString, text, useFullHeight, colorStyle, useHighlight) Because i believe the original function has a magical hidden self there. edit // goodamnit

Thank you so much this works out perfectly. Now how can one get knowledge about which function have such a hidden self?

[sticklord]

@ Tageshi: Yeah, beat me by a minute!

@ Miiru: Look at the post above mine.

[p3lim]

The self is not magically hidden.

The following does the same:

function SOMETHING:AddOne(two)
    print(self, two)
end

function SOMETHING.AddOne(self, two)
    print(self, two)
end

[Miiru]

So the right way to hook

function HeirloomsMixin:UpdateButton(button)

is

hooksecurefunc(HeirloomsMixin,"UpdateButton",function(self,button)

I am a bit confused because the HeirloomsMixin is not in caps, but i do not know if it is relevant.

[Tim]

http://wow.gamepedia.com/API_hooksecurefunc
http://wow.gamepedia.com/API_Frame_HookScript

You use both of them where it's needed.

[SDPhantom]

Frame:HookScript() only works on script handlers, not regular functions stored as table entries.

[Miiru]

So from reading this, i gather that

hooksecurefunc(HeirloomsMixin,"UpdateButton",function()
Print("Test")
end)

should work. Weirdly it does nothing at all, it does not even throw an error message.

Blizzard_HeirloomCollection.lua from ptr.

[Lombra]

I think that you need to hook HeirloomsJournal instead of HeirloomsMixin, as the former is the table that's used to call the method. Even though they're the same function in both tables, it's the table that matters when you hook it. Hooking can be confusing that way.

[Tim]

Originally Posted by SDPhantom Frame:HookScript() only works on script handlers, not regular functions stored as table entries.

Hence why I said "where it's needed".

[p3lim]

Originally Posted by Miiru Weirdly it does nothing at all, it does not even throw an error message. Blizzard_HeirloomCollection.lua from ptr.

You probably hooked it before the file was loaded.

[Miiru]

Originally Posted by Lombra I think that you need to hook HeirloomsJournal instead of HeirloomsMixin, as the former is the table that's used to call the method. Even though they're the same function in both tables, it's the table that matters when you hook it. Hooking can be confusing that way.

That indeed did the trick, thank you very much

[SDPhantom]

Originally Posted by p3lim You probably hooked it before the file was loaded.

hooksecurefunc() throws an error if used on a function that doesn't exist.

[Miiru]

I am running into the same problems again now that they are recoding the whole garrison code (why didnt they code it with tables in the first place?)

So i try to hook this function:

function GarrisonFollowerList:UpdateData() with

hooksecurefunc(GarrisonFollowerList,"UpdateData",miirgui_UpdateData)

when miirgui_UpdateData simply prints test. It does absolutely nothing. It does also not print a test message. So i recon it is the same problem as i had with the heirloom stuff.

Yet i cant seem to identify which is the right table to hook from now :/
Blizzard_GarrisonSharedTemplates.lua

[Miiru]

Seems like a have to use hooksecurefunc(GarrisonMissionFrameFollowers,"UpdateData",miirgui_UpdateData). If anybody cares