Differences

This shows you the differences between two versions of the page.

--- arma:config:common_errors [2009-04-26 14:49]
snakeman created common_errors initial page.
+++ arma:config:common_errors [2009-04-26 15:40] (current)
@@ Line 2: / Line 2: @@
 ArmA common errors in configs which you should and need to avoid at all cost.
+===== Changing the inheritance of existing classes =====
 For example on many many addons (even in BIS material) you'll see this [[arma:arma.rpt|arma.rpt]] error:
@@ Line 7: / Line 9: @@
 Updating base class ->MGunCore, by ca\weapons\config.bin/cfgWeapons/MGun/
 </code>
-You can avoid this error by not changing the MGun class, instead using your own new class by inheriting from this MGun directly.
+This happens because an addon changes the inheritance of a class that has already been defined. In the example above,
+BIS themselves does this in the ''Addons\weapons.pbo'' addon, where the basic class ''MGun'' is altered from
+having no parent class to having the class ''MGunCore'' as the parent.
+The warning is printed like this:
+''Updating base class //OldClass//->**//NewClass//**, by \path\to\the\config.bin/CfgSomeClass/**Classname**''
+This means that ''**Classname**'' was changed from being based on the old base class (''//OldClass//'') to the new base class (''**//NewClass//**'').
+(In the ''MGun'' [[arma:arma.rpt|arma.rpt]] error example, ''//OldClass//'' was empty, ie ''MGun'' did not have a parent class.)
+How do you avoid this warning? It's simple: **don't change the inheritance of existing classes**
-These are few examples how its done.
+===== Altering existing classes =====
+Sometimes you see addons that not only alters the inheritance of existing BIS classes, but then proceeds to make changes to the classes themselves.
+An example of this can be seen below:
 Bad config:
 <code cpp>
-	class MGunCore;
+class MGunCore;
-	class MGun: MGunCore
+class MGun: MGunCore
-	{
+{
-		displayName = "MyCoolGun";
+	displayName = "MyCoolGun";
-	};
+};
 </code>
+That's just bad form. What you should do instead is create your own machine gun class and let it inherit from the existing BIS class.
 Good config:
 <code cpp>
-	class MGun;
+class MGun;
-	class TAG_MGun: MGun
+class TAG_MGun: MGun
-	{
+{
-		displayName = "MyCoolGun";
+	displayName = "MyCoolGun";
-	};
+};
 </code>
-Other common errors:
+===== Other common errors =====
 <code>
 Updating base class ->Default, by ca\anims\characters\config.bin/CfgMovesBasic/DefaultDie/

PMC Editing Wiki

User Tools

Site Tools

Differences

Page Tools