Differences

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--- tutorial:modding_tips [2019/07/24 13:08] – added "Applying changes without restarting Minecraft" fudge
+++ tutorial:modding_tips [2026/01/24 23:01] (current) – [Mixins] Rephrase parentheses elaborating upon the term "chain" (phrasing inspired by flirora and skynotthelimit on Discord) gauntrecluse
@@ Line 6: / Line 6: @@
   * Due to the injection-based approach of Fabric's API development, we don't tend to patch classes outright in a way visible to the end user. As such, you may occasionally find Fabric extensions of vanilla classes when you run into something you cannot do. For example:
-    * Block.Settings -> FabricBlockSettings
+    * Block.Settings -> FabricBlockSettings (except 1.20.5)
     * EntityType.Builder -> FabricEntityTypeBuilder
-  * While an official configuration system is being worked on, one replacement for now is to use Java .properties or JSON.
   * For a built-in resource pack or data pack, please ensure that an "assets/[mod id]" or "data/[mod id]" directory path is present, respectively! IDEA users might find themselves accidentally creating an "assets.[mod id]" directory - this won't work.
 ===== Mixins =====
+:!: //This segment will likely be removed from this page once it is ensured the information contained within it is detailed upon on more specialized pages.//
-  * To cast a class to an interface it doesn't implement, or cast a final class, or cast the mixin to your target class, you can use the "(TargetClass) (Object) sourceClassObject" trick.
+ It should be kept in mind whenever learning about Mixin in **any** capacity that any example is limited to its own situation. No example should be directly copied, and you should prioritize using examples as ways to better understand syntax and general principles, rather than a tutorial to achieve your specific goal. //Every// Mixin you make should be tailored to its isolated use-case.\\
-  * To modify a constructor, use "<init>" (or "<clinit>" for static constructors) as the method name. Please note that @Inject on constructors only works with @At("RETURN") - no other forms of injection are officially supported!
+Refer to relevant wikis and Discord help channels mentioned further in this section when you are in doubt or encounter an issue, getting direct help and asking questions is a natural and expected part of learning Mixins and should be prioritized when there is no obvious Wiki answer. This being kept in mind, the following are loose, general advice for using Mixin in your project.
-  * @Redirect and @ModifyConstant mixins cannot currently be nested (applied by more than one mod in the same area at the same time). This might change later in development - however, for now, alongside @Overwrite, please avoid them if possible (or discuss bringing the hook over to Fabric's API, or - for more niche things - consider putting it in a JAR-in-JAR once that's out).
-  * If you're adding custom fields or methods, especially if they're not attached to an interface - prefix them with "[modid]_" or another unique string. Essentially, "mymod_secretValue" instead of "secretValue". This is to avoid conflicts between mods adding a field or method named the same way!
+  * When needing to reference an instance of the target class in your Mixin and pass it to a method call or constructor, you cannot use ''this'' directly, as your Mixin class is not yet of the type of the target class. Instead, you must first cast to ''Object'' and then to the target class: ''(TargetClass) (Object) this''. This should not be used as a way to access the target class's fields or methods, as those can be accessed through ''@Shadow''.
+  * ''@Redirect'' and ''@ModifyConstant'' mixins cannot chain(that is, only one ''@Redirect'' or ''@ModifyConstant'' can be applied to the same target at a time, meaning that the second to be applied will fail, likely throwing a crash). Alongside @Overwrite, which is incredibly incompatible as it replaces the method outright, please avoid them if possible and prioritize using options provided by MixinExtras:
+    * MixinExtras, a library for Mixin bundled with Fabric, provides alternatives to the aforementioned options that can chain when used in the same place as another Mixin. Mainly, ''@WrapOperation'' and ''@ModifyExpressionValue'' can be used instead of ''@Redirect'' and ''@ModifyConstant'' for all cases which do not involve intentionally clashing with another mod. ''@Overwrite'' should almost //never// be used over more precise modifications using injectors. See the [[https://github.com/LlamaLad7/MixinExtras/wiki|official MixinExtras wiki]] for more details on the library's features.
+  * If you're adding custom fields or methods to a target class, prefix them with your modid and a separator such as ''$'' or ''_'' and annotate them with ''@Unique''. Such that ''addedField'' is instead named ''mymodid$addedField''. This is to avoid conflicts between mods adding a field or method named the same way. This applies both to fields you add to the Mixin class, and to [[tutorial:mixin_accessors|accessor]] methods which are not static.
+To learn more on Mixins and how to use them, refer to [[tutorial:mixin_introduction|the introduction page]], the official [[https://github.com/SpongePowered/Mixin/wiki|Mixin Wiki]], the [[https://github.com/LlamaLad7/MixinExtras/wiki|MixinExtras Wiki]] and **most importantly** frequently ask questions in the Fabric Discord's dedicated ''#mod-dev-mixin'' channel, or the SpongePowered Discord's ''#mixin'' channel.
 ===== Networking =====
@@ Line 22: / Line 28: @@
   * Packets always begin execution on the **network thread**, however accesses to most Minecraft things are not thread-safe. In general, if you're not exactly sure what you're doing, you want to parse the packet on the network thread (read all the values out), then use the **task queue** to perform additional operations on the **main server/client thread**.
+===== Pitfalls =====
-===== Applying changes without restarting Minecraft =====
+  * Avoid using the ''java.awt'' or ''javax.swing'' package and their subpackages. AWT does not work well on all systems. Several users have reported that it hangs Minecraft.
-Restarting Minecraft can take a hefty amount of time. Thankfully, there are tools that allow you to some apply changes while the game is running.
-==== Reload changed classes ====
-In Eclipse or Intellij IDEA, run Minecraft in debug mode. To apply changes in code,
-do ''run -> reload changes classes'' in Intellij or save in Eclipse.
-Note: this only allows you to change method bodies. If you do any other kind of change, You will have to restart.
-However, if you use [[http://dcevm.github.io/|DCEVM]], you will be able to do most changes, including adding and removing methods and classes.
-==== Reload textures ====
-After you make a change in a texture (''.png'') asset, you can press ''F3 + T''  to apply the change without restarting Minecraft.