Fix #186 - Add RTL support to the compose form textarea and statuses output

app/assets/javascripts/components/components/autosuggest_textarea.jsx

@@ -1,5 +1,6 @@
 import AutosuggestAccountContainer from '../features/compose/containers/autosuggest_account_container';
 import ImmutablePropTypes from 'react-immutable-proptypes';
+import { isRtl } from '../rtl';
 
 const textAtCursorMatchesToken = (str, caretPosition) => {
   let word;
@@ -176,6 +177,11 @@ const AutosuggestTextarea = React.createClass({
     const { value, suggestions, fileDropDate, disabled, placeholder, onKeyUp } = this.props;
     const { isFileDragging, suggestionsHidden, selectedSuggestion } = this.state;
     const className = isFileDragging ? 'autosuggest-textarea__textarea file-drop' : 'autosuggest-textarea__textarea';
+    const style     = { direction: 'ltr' };
+
+    if (isRtl(value)) {
+      style.direction = 'rtl';
+    }
 
     return (
       <div className='autosuggest-textarea'>
@@ -192,6 +198,7 @@ const AutosuggestTextarea = React.createClass({
           onBlur={this.onBlur}
           onDragEnter={this.onDragEnter}
           onDragExit={this.onDragExit}
+          style={style}
         />
 
         <div style={{ display: (suggestions.size > 0 && !suggestionsHidden) ? 'block' : 'none' }} className='autosuggest-textarea__suggestions'>

app/assets/javascripts/components/components/status_content.jsx

@@ -2,6 +2,7 @@ import ImmutablePropTypes from 'react-immutable-proptypes';
 import PureRenderMixin from 'react-addons-pure-render-mixin';
 import escapeTextContentForBrowser from 'escape-html';
 import emojify from '../emoji';
+import { isRtl } from '../rtl';
 import { FormattedMessage } from 'react-intl';
 import Permalink from './permalink';
 
@@ -92,6 +93,11 @@ const StatusContent = React.createClass({
 
     const content = { __html: emojify(status.get('content')) };
     const spoilerContent = { __html: emojify(escapeTextContentForBrowser(status.get('spoiler_text', ''))) };
+    const directionStyle = { direction: 'ltr' };
+
+    if (isRtl(status.get('content'))) {
+      directionStyle.direction = 'rtl';
+    }
 
     if (status.get('spoiler_text').length > 0) {
       let mentionsPlaceholder = '';
@@ -116,14 +122,14 @@ const StatusContent = React.createClass({
 
           {mentionsPlaceholder}
 
-          <div style={{ display: hidden ? 'none' : 'block' }} dangerouslySetInnerHTML={content} />
+          <div style={{ display: hidden ? 'none' : 'block', ...directionStyle }} dangerouslySetInnerHTML={content} />
         </div>
       );
     } else {
       return (
         <div
           className='status__content'
-          style={{ cursor: 'pointer' }}
+          style={{ cursor: 'pointer', ...directionStyle }}
           onMouseDown={this.handleMouseDown}
           onMouseUp={this.handleMouseUp}
           dangerouslySetInnerHTML={content}

app/assets/javascripts/components/rtl.jsx

@@ -0,0 +1,27 @@
+// U+0590  to U+05FF  - Hebrew
+// U+0600  to U+06FF  - Arabic
+// U+0700  to U+074F  - Syriac
+// U+0750  to U+077F  - Arabic Supplement
+// U+0780  to U+07BF  - Thaana
+// U+07C0  to U+07FF  - N'Ko
+// U+0800  to U+083F  - Samaritan
+// U+08A0  to U+08FF  - Arabic Extended-A
+// U+FB1D  to U+FB4F  - Hebrew presentation forms
+// U+FB50  to U+FDFF  - Arabic presentation forms A
+// U+FE70  to U+FEFF  - Arabic presentation forms B
+
+const rtlChars = /[\u0590-\u083F]|[\u08A0-\u08FF]|[\uFB1D-\uFDFF]|[\uFE70-\uFEFF]/mg;
+
+export function isRtl(text) {
+  if (text.length === 0) {
+    return false;
+  }
+
+  const matches = text.match(rtlChars);
+
+  if (!matches) {
+    return false;
+  }
+
+  return matches.length / text.trim().length > 0.3;
+};

app/helpers/stream_entries_helper.rb

@@ -37,4 +37,17 @@ module StreamEntriesHelper
   def proper_status(status)
     status.reblog? ? status.reblog : status
   end
+
+  def rtl?(text)
+    return false if text.empty?
+
+    matches = /[\p{Hebrew}|\p{Arabic}|\p{Syriac}|\p{Thaana}|\p{Nko}]+/m.match(text)
+
+    return false unless matches
+
+    rtl_size = matches.to_a.reduce(0) { |acc, elem| acc + elem.size }.to_f
+    ltr_size = text.strip.size.to_f
+
+    rtl_size / ltr_size > 0.3
+  end
 end

app/views/stream_entries/_detailed_status.html.haml

@@ -10,7 +10,7 @@
   .status__content.e-content.p-name.emojify<
     - unless status.spoiler_text.blank?
       %p= status.spoiler_text
-    = Formatter.instance.format(status)
+    %div{ style: "direction: #{rtl?(status.content) ? 'rtl' : 'ltr'}" }= Formatter.instance.format(status)
 
   - unless status.media_attachments.empty?
     - if status.media_attachments.first.video?

app/views/stream_entries/_simple_status.html.haml

@@ -15,7 +15,7 @@
   .status__content.e-content.p-name.emojify<
     - unless status.spoiler_text.blank?
       %p= status.spoiler_text
-    = Formatter.instance.format(status)
+    %div{ style: "direction: #{rtl?(status.content) ? 'rtl' : 'ltr'}" }= Formatter.instance.format(status)
 
   - unless status.media_attachments.empty?
     .status__attachments