Merge pull request #4 from tobscure/setattribute-fix

Remove setAttribute calls from constructors to comply with Custom Elements spec

Author: muan

index.js

@@ -55,9 +55,13 @@ if (!window.customElements.get('md-header')) {
 class MarkdownBoldButtonElement extends MarkdownButtonElement {
   constructor() {
     super()
-    this.setAttribute('hotkey', 'b')
     styles.set(this, {prefix: '**', suffix: '**', trimFirst: true})
   }
+
+  connectedCallback() {
+    super.connectedCallback()
+    this.setAttribute('hotkey', 'b')
+  }
 }
 
 if (!window.customElements.get('md-bold')) {
@@ -68,9 +72,13 @@ if (!window.customElements.get('md-bold')) {
 class MarkdownItalicButtonElement extends MarkdownButtonElement {
   constructor() {
     super()
-    this.setAttribute('hotkey', 'i')
     styles.set(this, {prefix: '_', suffix: '_', trimFirst: true})
   }
+
+  connectedCallback() {
+    super.connectedCallback()
+    this.setAttribute('hotkey', 'i')
+  }
 }
 
 if (!window.customElements.get('md-italic')) {
@@ -105,9 +113,13 @@ if (!window.customElements.get('md-code')) {
 class MarkdownLinkButtonElement extends MarkdownButtonElement {
   constructor() {
     super()
-    this.setAttribute('hotkey', 'k')
     styles.set(this, {prefix: '[', suffix: '](url)', replaceNext: 'url', scanFor: 'https?://'})
   }
+
+  connectedCallback() {
+    super.connectedCallback()
+    this.setAttribute('hotkey', 'k')
+  }
 }
 
 if (!window.customElements.get('md-link')) {
@@ -142,9 +154,13 @@ if (!window.customElements.get('md-ordered-list')) {
 class MarkdownTaskListButtonElement extends MarkdownButtonElement {
   constructor() {
     super()
-    this.setAttribute('hotkey', 'L')
     styles.set(this, {prefix: '- [ ] ', multiline: true, surroundWithNewlines: true})
   }
+
+  connectedCallback() {
+    super.connectedCallback()
+    this.setAttribute('hotkey', 'L')
+  }
 }
 
 if (!window.customElements.get('md-task-list')) {