How To Add Addons To World Of Warcraft

I never experienced Earth of Warcraft. I played other Blizzard games, both earlier and after its release, including the original Warcraft series and Diablo. I skipped over WoW for reasons I can't completely recall. During the hype around "classic" I tried "retail" for a moment and abruptly stopped due to a movement to a new home. I was tempted to play again afterward learning about "vanilla" servers but had already mentally committed myself to look for the official servers. Classic finally launched on August 26, 2019 and I joined in equally to not miss out on the twice in a lifetime experience.

Minutes passed during my group's first play of the game and the chatter started about all the addons they just had to install. Unlike me they had played on and off for the last fifteen years, both vanilla and retail. Not having a clue, I played for a few sittings before getting the itch. What addons were out there and what they could practice for me? Everyone had then much experience I idea it was but off-white that I bridge the gap. I installed quite a few addons while feeling like a kid in a candy shop. With all my handicaps addressed I was firmly hooked.

Then, out of nowhere, my curiosity got the best of me. How practise these things work?!

This commodity assumes you take at least some basic noesis in software development and are at to the lowest degree interested in how the World of Warcraft addon system works. I'm a software engineer by merchandise simply I've never written a game addon earlier, then information technology's non a requirement that you have either. If you lot've used or written a macro in game you're already ahead.

Setting up the Evolution Environs

Nosotros're going to demand an editor to develop this addon. Older tutorials volition recommend you lot the nigh basic of text editors, which will work, but nosotros can exercise amend than that. If you don't already have a preference I would recommend downloading Microsoft Visual Studio Lawmaking. That should exist more than than enough for this journey and enable future programming endeavors. I have crossed paths with vscode plugins touting both Lua and World of Warcraft support only the editor is sufficient out of the box for what is needed here. Do explore the bachelor extensions and brand your own determination on their usefulness.

Creating a Folder for the Addon

How you manage your project long term is upwards to you. I'd recommend using GitHub to manage your code and merely update your local addon directory when you are set up to test a new version, perchance with a deployment script. For now, since nosotros are merely getting started, allow's just work out of the Addons directory.

Provided you haven't inverse the default install location the World of Warcraft directory will either be located in C:\Program Files or C:\Program Files (X86) on Windows or the /Applications/ on a Mac. Depending on what you have installed you will may see _classic_ and _retail_ and _ptr_ folders in that directory. Open up _classic_/Interface/Addons and create a Sandbox folder. An addon is born!

Creating the Table of Contents

In the Sandbox folder create a new text file named Sandbox.toc. This file provides the information required well-nigh the addon to the WoW client. If you've ever looked at package.json in a JavaScript project for example, this serves a similar purpose.

Add the post-obit to the file:

            ## Interface: 11302 ## Title: Sandbox ## Notes: A identify to experiment. ## Author: haxorjim ## Version: one.0  Sandbox.lua

The correct value for Interface can exist constitute in game by running the following control: /run print((select(4, GetBuildInfo()))); At the fourth dimension of writing archetype is currently 11302. If you lot intend on targeting retail or vanilla instead be sure to update that value.

Following that, I believe Title, Notes, Author and Version are self explanatory. There are quite a few other values that I've observed in toc files, I would recommend peeking into other addons to discover those.

The terminal line Sandbox.lua is a pointer to where the actual code volition be stored. At least ane file is required, but for larger plugins multiple files tin can be referenced hither and all will be loaded at runtime.

Out of curiosity I played around with changing directory names, file names and removing more details from the toc file. There wasn't much that really caused the addon to neglect to part. It'southward definitely going to be good practice to take a detailed tabular array of contents file, so the above is what I'd recommend as the minimum.

Writing Some Lawmaking

World of Warcraft addons are written in Lua which touts itself as "a powerful, efficient, lightweight, embeddable scripting language." Lua should not exist much attempt to pick up if you lot have at least i language under your chugalug. If not, information technology will still exist an excellent showtime language to learn.

To begin coding in Lua, create a Sandbox.lua file in the Sandbox folder that nosotros created earlier and add the following lawmaking:

                          Sandbox              =              {              }              function              Sandbox              :              HelloWorld              ()              bulletin              (              "Hello Earth!"              )              end              function              Sandbox              :              HideGryphons              ()              MainMenuBarLeftEndCap              :              Hide              ()              MainMenuBarRightEndCap              :              Hide              ()              end

Additionally select 1 of the following samples of code and add it to the very end of the file:

Option A:

Selection B:

Trying It Out

Time to kick up the game… No playing! Focus! When yous enter the game one of two things should happen. If you selected Selection A you should see "Hello Globe!" displayed in a graphical window:

If yous selected Option B the results are a scrap more than mysterious. Where have the gryphons gone?

Congratulations! Your first addon is complete!

Across the Basics

At that place's a lot more than full general programming that tin exist washed inside a addon but I won't be going deep into Lua here at all as there are plenty of books already bachelor to reference for the subject. There are even books such every bit Beginning Lua with Earth of Warcraft Add-ons and World of Warcraft Programming: A Guide and Reference for Creating WoW Addons specifically for World of Warcraft.

Finding out how to create or modify different elements in the WoW client is challenging and requires cognition of the available API. The all-time resources for the API I've found and then far are Wowpedia and WoWWiki.

Additionally a nifty way to learn how to practice things is to take a look at Lua files in existing addons either that you take installed or those available on the web. Practise be advised, mileage volition vary with what is supported in different Earth of Warcraft client versions.

Limitations & Workarounds

There were a couple of interesting limitations I constitute while writing this article. The offset is to telephone call out to a url to GET or Mail service data. If it did exist, could have some pretty serious malicious abuses, so I'm not surprised it'due south non there. It would have definitely been useful for some slick addons.

Another limitation is the inability to save data to an external file or read from an external file. This isn't too limiting to addon developers as you have access to saved variables and tin can load as many Lua files equally you lot please. Some plugins like CensusClassicPlus are getting effectually this limitation by having users upload files from their SavedVariables folder later on logging out of the game.

Despite non existence able to communicate directly over the Cyberspace, addons still announced to be able to communicate with each other with some tricks. For instance RealMobHealth and ClassicThreatMeter are using in game chat to ship information betwixt users in the current group who besides have the addon installed.

Finally, not so much a limitation only a consideration is the variances betwen capabilities in the API between game versions. Since now we have classic, vanilla (which is multiple versions in itself) and retail the API is not always the same. Plugins will need to be tested and coded to work on all platforms, or merely on a specific platform as not all are created equal. Ane style to arrange would be to switch addon executation paths programatically based on the game version retrieved from GetBuildInfo().

Debugging

While you lot are developing it will exist useful to stay logged into the game. This allows you to switch in and out to make some changes to the addon, run /reload to restart the UI and keep debugging. Bulk of the time your changes volition be reflected unless you are doing something with changing files names or the toc file. Information technology will also be useful to execute /console scriptErrors ane during your coding session so that when Lua errors occur they are displayed immediately. But don't forget to turn information technology off using /panel scriptErrors 0 before you go back to normal gameplay. As always, impress and bulletin functions volition be your friend! Finally, in that location are likewise some interesting looking addons that may be of additional assistance including BugSack and BugGrabber which "eases the process of viewing bugs".

Testing

While your addon may not abound large enough to justify any robust testing patterns it is a good idea to consider at least some basic testing strategies before things plow into spaghetti. The structure that was snuck into the instance addon it allows for manual testing of functions by running manual commands, for instance:

            /run Sandbox:HelloWorld()

A surprising option that is available is WowUnit which "allows you to easily write unit of measurement tests for your Earth of Warcraft addons and provides an interface to monitor them". This is probably the best choice for the majority of addons that require testing.

Lastly, for addons with considerable internal logic, it is very possible Lua itself could be used to test the addon without requiring the WoW client to be running. This would require mocking out parts of the WoW API and using a Lua interpreter to run your tests. While the nigh avant-garde selection it would also be the most extendable.

Publishing

I assumed addons would need to manually acquired and installed by hand. However the Twitch client can automatically install addons for y'all besides every bit go along them in sync beyond machines using their client. You lot don't have to be a streamer to use it. It works in conjunction with Curseforge, a directory of addons for multiple games. With millions of downloads for the most popular addons I would definitely recommend publishing to get exposure. In addition I'd once more recommend using GitHub to permit others to interact and assistance maintain your addon. If you terminate up being inspired to create an addon, here are the instructions for creating and submitting a project.

Final Thoughts

I started this commodity to larn more than most how addons worked inside Earth of Warcraft. What I discovered was a robust framework with all the tools I would await from a development environment bachelor to me. I've institute myself torn betwixt playing the game and continuing to expect under the hood. At that place are numerous addons already bachelor for WoW but nothing I've come beyond has felt like the end all be all. Much more could exist done and there is considerable room for improvement. If the feedback to this article is positive I would absolutely consider writing a series of manufactures on this topic.