From ac4f254a4f761478b7c97ba08d151c361b9dcd5a Mon Sep 17 00:00:00 2001
From: Liam DeBeasi <liamdebeasi@users.noreply.github.com>
Date: Wed, 2 Oct 2019 10:42:53 -0400
Subject: [PATCH] refactor(): remove [main] from split-pane (#19511)

---
 core/src/components.d.ts                      |  4 ++--
 core/src/components/split-pane/readme.md      | 10 +++++-----
 core/src/components/split-pane/split-pane.tsx |  4 +---
 3 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/core/src/components.d.ts b/core/src/components.d.ts
index 0ea0da2563..7cb1da1cd6 100644
--- a/core/src/components.d.ts
+++ b/core/src/components.d.ts
@@ -2457,7 +2457,7 @@ export namespace Components {
   }
   interface IonSplitPane {
     /**
-    * The content `id` of the split-pane's main content. This property can be used instead of the `[main]` attribute to select the `main` content of the split-pane.
+    * The content `id` of the split-pane's main content.
     */
     'contentId'?: string;
     /**
@@ -5706,7 +5706,7 @@ declare namespace LocalJSX {
   }
   interface IonSplitPane {
     /**
-    * The content `id` of the split-pane's main content. This property can be used instead of the `[main]` attribute to select the `main` content of the split-pane.
+    * The content `id` of the split-pane's main content.
     */
     'contentId'?: string;
     /**
diff --git a/core/src/components/split-pane/readme.md b/core/src/components/split-pane/readme.md
index ac589c584e..19fdcc0eed 100644
--- a/core/src/components/split-pane/readme.md
+++ b/core/src/components/split-pane/readme.md
@@ -133,11 +133,11 @@ export const SplitPlaneExample: React.SFC<{}> = () => (
 
 ## Properties
 
-| Property    | Attribute    | Description                                                                                                                                                    | Type                  | Default       |
-| ----------- | ------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------- | ------------- |
-| `contentId` | `content-id` | The content `id` of the split-pane's main content. This property can be used instead of the `[main]` attribute to select the `main` content of the split-pane. | `string \| undefined` | `undefined`   |
-| `disabled`  | `disabled`   | If `true`, the split pane will be hidden.                                                                                                                      | `boolean`             | `false`       |
-| `when`      | `when`       | When the split-pane should be shown. Can be a CSS media query expression, or a shortcut expression. Can also be a boolean expression.                          | `boolean \| string`   | `QUERY['lg']` |
+| Property    | Attribute    | Description                                                                                                                           | Type                  | Default       |
+| ----------- | ------------ | ------------------------------------------------------------------------------------------------------------------------------------- | --------------------- | ------------- |
+| `contentId` | `content-id` | The content `id` of the split-pane's main content.                                                                                    | `string \| undefined` | `undefined`   |
+| `disabled`  | `disabled`   | If `true`, the split pane will be hidden.                                                                                             | `boolean`             | `false`       |
+| `when`      | `when`       | When the split-pane should be shown. Can be a CSS media query expression, or a shortcut expression. Can also be a boolean expression. | `boolean \| string`   | `QUERY['lg']` |
 
 
 ## Events
diff --git a/core/src/components/split-pane/split-pane.tsx b/core/src/components/split-pane/split-pane.tsx
index 744a4625cf..81171d55da 100644
--- a/core/src/components/split-pane/split-pane.tsx
+++ b/core/src/components/split-pane/split-pane.tsx
@@ -29,8 +29,6 @@ export class SplitPane implements ComponentInterface {
 
   /**
    * The content `id` of the split-pane's main content.
-   * This property can be used instead of the `[main]` attribute to select the `main`
-   * content of the split-pane.
    */
   @Prop() contentId?: string;
 
@@ -151,7 +149,7 @@ AFTER:
     let foundMain = false;
     for (let i = 0; i < nu; i++) {
       const child = children[i] as HTMLElement;
-      const isMain = contentId !== undefined ? child.id === contentId : child.hasAttribute('main');
+      const isMain = contentId !== undefined && child.id === contentId;
       if (isMain) {
         if (foundMain) {
           console.warn('split pane cannot have more than one main node');