Add inheritPlaceholder option

src/js/base/Context.js

@@ -54,6 +54,11 @@ export default class Context {
   }
 
   _initialize() {
+    // apply original placeholder
+    if (this.options.inheritPlaceholder && this.$note.attr('placeholder')) {
+      this.options.placeholder = this.$note.attr('placeholder');
+    }
+
     // add optional buttons
     const buttons = $.extend({}, this.options.buttons);
     Object.keys(buttons).forEach((key) => {

src/js/base/settings.js

@@ -125,6 +125,8 @@ $.summernote = $.extend($.summernote, {
     maxTextLength: 0,
     blockquoteBreakingLevel: 2,
     spellCheck: true,
+    placeholder: null,
+    inheritPlaceholder: false,
 
     styleTags: ['p', 'blockquote', 'pre', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6'],
 

test/base/module/Placeholder.spec.js

@@ -0,0 +1,31 @@
+/**
+ * Placeholder.spec.js
+ * (c) 2015~ Summernote Team
+ * summernote may be freely distributed under the MIT license./
+ */
+import chai from 'chai';
+import $ from 'jquery';
+import Context from '../../../src/js/base/Context';
+import '../../../src/js/bs4/settings';
+
+describe('Placeholder', () => {
+  var assert = chai.assert;
+
+  it('should not be initialized by placeholder attribute without inheritPlaceHolder', () => {
+    var options = $.extend({}, $.summernote.options);
+    var context = new Context($('<textarea placeholder="custom_placeholder"><p>hello</p></textarea>'), options);
+    var $editor = context.layoutInfo.editor;
+
+    assert.isTrue($editor.find('.note-placeholder').length === 0);
+  });
+
+  it('should be initialized by placeholder attribute with inheritPlaceHolder', () => {
+    var options = $.extend({}, $.summernote.options);
+    options.inheritPlaceholder = true;
+    var context = new Context($('<textarea placeholder="custom_placeholder"><p>hello</p></textarea>'), options);
+    var $editor = context.layoutInfo.editor;
+
+    assert.isTrue($editor.find('.note-placeholder').length === 1);
+    assert.isTrue($editor.find('.note-placeholder').html() === 'custom_placeholder');
+  });
+});