Editing WoW:AddOn programming tutorial/Introduction (section)

=== Running your HelloWorld AddOn ===
You should have a directory under your AddOns directory named "HelloWorld" and in that directory should be three files named HelloWorld.toc, HelloWorld.lua, and HelloWorld.xml. The contents of these three files should be EXACTLY as described above.

Now start WoW and log into your account, but don't select your character yet. Click the red ''''AddOns'''' button on the lower left of the character-selection screen to see all of the AddOns WoW has detected; there will be one for every folder in your AddOns directory except for the AddOns starting with Blizzard_.

You should see your new HelloWorld in this list. The name should be yellow, and the checkbox to the left should be checked.

If the name is red and you see an '''Out of date''' message to the right, you probably didn't change the '''## Interface: 30300''' value as described above under [[#The .toc or Table of Contents|The .toc or Table of Contents]]. Review that section and make the appropriate change. Running your AddOns with the 'Load out of date AddOns' checkbox checked is not recommended. That's asking for trouble as an AddOn that attempts to use old UI features can corrupt a new UI. Nearly every patch that changes the UI level has had problems with old AddOns that have not been updated to conform to the new UI standards.

If you don't see the name at all, make sure that you have placed the HelloWorld directory in the AddOns directory, which is in the Interface directory under the WoW installation location. On a Windows system, it would be 'C:\Program Files\World of Warcraft\Interface\AddOns\HelloWorld'. The files inside that directory should all start with 'HelloWorld' and have the .toc, .lua, and .xml endings.

A note for Windows users; make sure that you have not saved the files as HelloWorld.toc.txt, etc., as an option in Windows Explorer will hide the .txt on the end.

Please note the CaSe of the names. While Windows is insensitive to case for directory and file names, the case is important to other systems (e.g. Mac, Linux). Also, inside the game itself, WoW is sensitive to the case for the names of its variables and filenames. Keep the case the same to avoid problems.

Now you have a yellow Hello, World! showing up in your AddOn list. Note the ! in the name. The name of the AddOn shown in this list is taken from the '''## Title: Hello, World!''' line in the HelloWorld.toc file. In the future, we will see how to change colors and languages.

If you move your mouse cursor over the Hello, World! name, you should see a tool-tip pop up with two lines in it. The first line is the same as the Title, and the second line is taken from the '''## Notes: My first AddOn''' line in the .toc file. This can also be customized for color and language.

Cancel out of the AddOns display and enter the world with any of your characters. Once your character loads, you should see a message in the default chat window that says "'''Hello, World!'''".

Success!!