XML and Lua

[Sweetsour]

Hey guys,

I'm trying to get my frame from my XML file to show via Lua code. This is what I have so far.

<Frame name="TrackerDialog" hidden="true" virtual="true" frameStrata="DIALOG" parent="UIParent">
        <Size x="200" y="325"/>
        </Size>
        <Backdrop bgFile="Interface\DialogFrame\UI-DialogBox-Background-Dark" edgeFile="Interface\DialogFrame\UI-DialogBox-Border">
		<BackgroundInsets>
			<AbsInset left="11" right="12" top="12" bottom="11"/>
		</BackgroundInsets>
		<EdgeSize>
			<AbsValue val="10"/>
		</EdgeSize>
        </Backdrop>
        <Anchors>
		<Anchor point="TOP">
			<Offset>
				<AbsDimension x="0" y="-500" />
			</Offset>
		</Anchor>
	</Anchors>
        <Scripts>
		<OnMouseDown>self:StartMoving();</OnMouseDown>
		<OnMouseUp>self:StopMovingOrSizing();</OnMouseUp>
		<OnDragStop>self:StopMovingOrSizing();</OnDragStop>
        </Scripts>
		<Frames>
			<Frame name="StatusGrp">
				<Size x="180" y="75" />
				<Backdrop edgeFile="Interface/Tooltips/UI-Tooltip-Border">
					<EdgeSize>
						<AbsValue val="10"/>
					</EdgeSize>
				</Backdrop>
				<Anchors>
					<Anchor point="TOP">
						<Offset>
							<AbsDimension x="0" y="-10" />
						</Offset>
					<Anchor>
				</Anchors>
			</frame>
		</Frames>
    </Frame>

Then I try to show the frame with the following code, and get an error saying it's a nil value

TrackerDialog:Show();

I feel like I'm missing something.

[semlar]

You have the attribute virtual="true" set, which turns the frame into a template rather than an actual frame.

[Sweetsour]

Ah, good to know! Though, having done that, I'm still getting nothing to appear. Here's all the code that I have:

.TOC file

## Interface: 60200
## Title: Tracker
## Notes: <notes>
## Author: <name>
## Version: <versiom>

Core.lua
Tracker.xml

Tracker.xml

<Ui xmlns="http://www.blizzard.com/wow/ui/"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://www.blizzard.com/wow/ui/..\..\FrameXML\UI.xsd">

	<Frame parent="UIParent" name="Tracker">
		<Anchors>
			<Anchor point="CENTER"/>
		</Anchors>
		<Scripts>
			<OnLoad>
				dTracker_OnLoad( self );
			</OnLoad>
			<OnEvent>
				Tracker_OnEvent( self, event, ... );
			</OnEvent>
		</Scripts>
	</Frame>

<!-- Dialog template -->
	<Frame name="Tracker_Dialog" hidden="false" frameStrata="DIALOG" parent="UIParent">
		<Size x="200" y="325"/>
		<Backdrop bgFile="Interface\DialogFrame\UI-DialogBox-Background-Dark" edgeFile="Interface\DialogFrame\UI-DialogBox-Border">
			<BackgroundInsets>
				<AbsInset left="11" right="12" top="12" bottom="11"/>
			</BackgroundInsets>
			<EdgeSize>
				<AbsValue val="10"/>
			</EdgeSize>
		</Backdrop>
		<Anchors>
			<Anchor point="TOP">
				<Offset>
					<AbsDimension x="0" y="-500" />
				</Offset>
			</Anchor>
		</Anchors>
		<Scripts>
			<OnMouseDown>self:StartMoving();</OnMouseDown>
			<OnMouseUp>self:StopMovingOrSizing();</OnMouseUp>
			<OnDragStop>self:StopMovingOrSizing();</OnDragStop>
		</Scripts>
		<Frames>
			<Frame name="StatusGrp">
				<Size x="180" y="75" />
				<Backdrop edgeFile="Interface/Tooltips/UI-Tooltip-Border">
					<EdgeSize>
						<AbsValue val="10"/>
					</EdgeSize>
				</Backdrop>
				<Anchors>
					<Anchor point="TOP">
						<Offset>
							<AbsDimension x="0" y="-10" />
						</Offset>
					<Anchor>
				</Anchors>
			</frame>
		</Frames>
    </Frame>
</Ui>

[semlar]

Looks like you aren't closing your anchor tag for your StatusGrp frame and you have a lowercase </frame> instead of </Frame>

[Sweetsour]

That was it! I also caught "<Size stuff /></Size>" and figured that may have caused some problems. Thanks for your help!

[Phanx]

Unless you really love XML and already have a workflow set up for writing XML (which it doesn't sound like you do) there's really no reason to use XML in a WoW addon (outside of a few specific advanced topics dealing with secure headers). Among other things, it makes debugging unnecessarily difficult. If you'd created your frame in Lua, you would have gotten a nice in-game error message telling you exactly what was wrong and where.

Also, regardless of whether you're using XML or not, you should avoid generic global frame and function names like "Tracker" and "Tracker_OnEvent". If they show up in a /framestack or an error message, there's no way to tell what addon they actually belong to, and you're just asking for your addon to get broken by some other addon (or by Blizzard) leaking a variable with the same generic name as a global, or for your addon to break the other addon (or the default UI) by overwriting its global.

General rules for using globals:

1. Don't do it unless you actually have to. This is another argument against XML, since it forces you to dump tons of stuff into the global namespace.

2. Make sure your global variables have unique names. "Tracker" is a bad frame name; "CoolRaidBuffTracker" or "SweetsourTracker" would be better choices.

3. Make sure your global variable names identify the addon that created them. As a happy coincidence, if your globals are prefixed with your addon's name, not only are they easily identifiable, but also much more likely to be unique.