plugin_extensions.md: structure EP properties

labels.list

@@ -20,6 +20,12 @@
     Deprecated, see notes.
   </primary-label>
 
+  <primary-label id="2019.2" short-name="2019.2+" name="2019.2+">
+    Available in IDE version 2019.2 or later
+  </primary-label>
+  <primary-label id="2019.3" short-name="2019.3+" name="2019.3">
+    Available in IDE version 2019.3 or later
+  </primary-label>
   <primary-label id="2020.1" short-name="2020.1+" name="2020.1+">
     Available in IDE version 2020.1 or later
   </primary-label>

topics/basics/plugin_structure/plugin_extensions.md

@@ -55,20 +55,20 @@ and one extension to access the `another.plugin.myExtensionPoint` extension poin
  -->
 <extensions defaultExtensionNs="com.intellij">
   <appStarter
-      implementation="com.example.MyAppStarter"/>
+          implementation="com.example.MyAppStarter"/>
   <projectTemplatesFactory
-      implementation="com.example.MyProjectTemplatesFactory"/>
+          implementation="com.example.MyProjectTemplatesFactory"/>
 </extensions>
 
-<!--
+        <!--
-  Declare extensions to access extension points in a custom plugin "another.plugin".
+          Declare extensions to access extension points in a custom plugin "another.plugin".
-  The "myExtensionPoint" extension point has been declared using "beanClass"
+          The "myExtensionPoint" extension point has been declared using "beanClass"
-  and exposes custom properties "key" and "implementationClass".
+          and exposes custom properties "key" and "implementationClass".
--->
+        -->
 <extensions defaultExtensionNs="another.plugin">
-  <myExtensionPoint
+<myExtensionPoint
-      key="keyValue"
+        key="keyValue"
-      implementationClass="com.example.MyExtensionPointImpl"/>
+        implementationClass="com.example.MyExtensionPointImpl"/>
 </extensions>
 ```
 
@@ -106,33 +106,48 @@ If an extension instance needs to "opt out" in certain scenarios, it can throw [
 
 Several tooling features are available to help configure bean class extension points in <path>plugin.xml</path>.
 
-Properties annotated with [`RequiredElement`](%gh-ic%/platform/core-api/src/com/intellij/openapi/extensions/RequiredElement.java) are inserted automatically and validated (2019.3 and later).
+#### Required Properties
-If the given property is allowed to have an explicit empty value, set `allowEmpty` to `true` (2020.3 and later).
+<primary-label ref="2019.3"/>
 
-Property names matching the following list will resolve to fully qualified class name:
+Properties annotated with [`RequiredElement`](%gh-ic%/platform/core-api/src/com/intellij/openapi/extensions/RequiredElement.java) are inserted automatically and validated.
+
+If the given property is allowed to have an explicit empty value, set `allowEmpty` to `true` (2020.3+).
+
+#### Class names
+
+Property names matching the following list will resolve to a fully qualified class name:
 
 - `implementation`
 - `className`
-- `serviceInterface` / `serviceImplementation`
 - ending with `Class` (case-sensitive)
+- `serviceInterface`/`serviceImplementation`
 
-A required parent type can be specified in the extension point declaration via nested [`<with>`](plugin_configuration_file.md#idea-plugin__extensionPoints__extensionPoint__with):
+A required parent type can be specified in the [extension point declaration](plugin_extension_points.md) via [`<with>`](plugin_configuration_file.md#idea-plugin__extensionPoints__extensionPoint__with):
 
 ```xml
 
 <extensionPoint name="myExtension" beanClass="MyExtensionBean">
-  <with
+  <with attribute="psiElementClass"
-      attribute="psiElementClass"
+        implements="com.intellij.psi.PsiElement"/>
-      implements="com.intellij.psi.PsiElement"/>
 </extensionPoint>
 ```
 
-Property name `language` (or ending in `*Language`, 2020.2+) resolves to all present `Language` IDs.
+#### Custom resolve
 
-Similarly, `action`/`actionId` (2024.3+) resolves to all registered [`<action>`](plugin_configuration_file.md#idea-plugin__actions__action) IDs.
+Property name `language` (or ending in `*Language`, 2020.2+) resolves to all present [`Language`](%gh-ic%/platform/core-api/src/com/intellij/lang/Language.java) IDs.
 
-Annotating with [`@Nls`](%gh-java-annotations%/common/src/main/java/org/jetbrains/annotations/Nls.java) validates a UI `String` capitalization according to the text property `Capitalization` enum value (2019.2 and later).
+Similarly, `action` and `actionId` (2024.3+) resolve to all registered [`<action>`](plugin_configuration_file.md#idea-plugin__actions__action) IDs.
+
+#### Deprecation/ApiStatus
 
 Properties marked as `@Deprecated` or annotated with any of [`ApiStatus`](%gh-java-annotations%/common/src/main/java/org/jetbrains/annotations/ApiStatus.java) `@Internal`, `@Experimental`, `@ScheduledForRemoval`, or `@Obsolete` will be highlighted accordingly.
 
-Attributes with `Enum` type support code insight with _lowerCamelCased_ notation (2020.1 and later). Note: these must not override `toString()`.
+#### Enum properties
+<primary-label ref="2020.1"/>
+
+Attributes with `Enum` type support code insight with _lowerCamelCased_ notation. Note: Enum implementation must not override `toString()`.
+
+#### I18n
+<primary-label ref="2019.2"/>
+
+Annotating with [`@Nls`](%gh-java-annotations%/common/src/main/java/org/jetbrains/annotations/Nls.java) validates a UI `String` capitalization according to the text property `Capitalization` enum value.