Add support of i18n with related patches and support "en" and "zh" locales for now

10 files changed, 180 insertions, 147 deletions

diff --git a/public/css/cover.css b/public/css/cover.css
index bde3ec7c..ca0c6027 100644
--- a/public/css/cover.css
+++ b/public/css/cover.css
@@ -329,6 +329,10 @@ input {
     vertical-align: middle !important;
 }
 
+select {
+    color: black;
+}
+
 @media (max-width: 768px) {
     span.ui-or {
         display: block;
diff --git a/public/js/cover.js b/public/js/cover.js
index c97bd256..f3533826 100644
--- a/public/js/cover.js
+++ b/public/js/cover.js
@@ -291,7 +291,7 @@ $(".ui-logout").click(function () {
 
 var filtertags = [];
 $(".ui-use-tags").select2({
-    placeholder: 'Select tags...',
+    placeholder: $(".ui-use-tags").attr('placeholder'),
     multiple: true,
     data: function () {
         return {
diff --git a/public/js/locale.js b/public/js/locale.js
new file mode 100644
index 00000000..6fe7fdb6
--- /dev/null
+++ b/public/js/locale.js
@@ -0,0 +1,24 @@
+var lang = "en";
+var userLang = navigator.language || navigator.userLanguage;
+var userLangCode = userLang.split('-')[0];
+var userCountryCode = userLang.split('-')[1];
+var locale = $('.ui-locale');
+var supportLangs = [];
+$(".ui-locale option").each(function() {
+    supportLangs.push($(this).val());
+});
+if (Cookies.get('locale')) {
+    lang = Cookies.get('locale');
+} else if (supportLangs.indexOf(userLang) !== -1) {
+    lang = supportLangs[supportLangs.indexOf(userLang)];
+} else if (supportLangs.indexOf(userLangCode) !== -1) {
+    lang = supportLangs[supportLangs.indexOf(userLangCode)];
+}
+
+locale.val(lang);
+locale.change(function() {
+    Cookies.set('locale', $(this).val(), {
+        expires: 365
+    });
+    window.location.reload();
+});
\ No newline at end of file
diff --git a/public/views/body.ejs b/public/views/body.ejs
index acf929ad..28680e49 100644
--- a/public/views/body.ejs
+++ b/public/views/body.ejs
@@ -43,15 +43,15 @@
             <div class="modal-header">
                 <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span>
                 </button>
-                <h4 class="modal-title" id="myModalLabel">Import from clipboard</h4>
+                <h4 class="modal-title" id="myModalLabel"><%= __('Import from clipboard') %></h4>
             </div>
             <div class="modal-body">
-                <div contenteditable data-ph="Paste your markdown or webpage here..." id="clipboardModalContent" style="overflow:auto;max-height:50vh"></div>
+                <div contenteditable data-ph="<%= __('Paste your markdown or webpage here...') %>" id="clipboardModalContent" style="overflow:auto;max-height:50vh"></div>
             </div>
             <div class="modal-footer">
-                <button type="button" class="btn btn-default" data-dismiss="modal">Cancel</button>
-                <button type="button" class="btn btn-danger" id="clipboardModalClear">Clear</button>
-                <button type="button" class="btn btn-primary" id="clipboardModalConfirm">Import</button>
+                <button type="button" class="btn btn-default" data-dismiss="modal"><%= __('Cancel') %></button>
+                <button type="button" class="btn btn-danger" id="clipboardModalClear"><%= __('Clear') %></button>
+                <button type="button" class="btn btn-primary" id="clipboardModalConfirm"><%= __('Import') %></button>
             </div>
         </div>
     </div>
@@ -63,13 +63,13 @@
             <div class="modal-header">
                 <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span>
                 </button>
-                <h4 class="modal-title" id="myModalLabel"><i class="fa fa-lock"></i> This note is locked</h4>
+                <h4 class="modal-title" id="myModalLabel"><i class="fa fa-lock"></i> <%= __('This note is locked') %></h4>
             </div>
             <div class="modal-body" style="color:black;">
-                <h5>Sorry, only owner can edit this note.</h5>
+                <h5><%= __('Sorry, only owner can edit this note.') %></h5>
             </div>
             <div class="modal-footer">
-                <button type="button" class="btn btn-danger" data-dismiss="modal">OK</button>
+                <button type="button" class="btn btn-danger" data-dismiss="modal"><%= __('OK') %></button>
             </div>
         </div>
     </div>
@@ -81,14 +81,14 @@
             <div class="modal-header">
                 <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span>
                 </button>
-                <h4 class="modal-title" id="myModalLabel"><i class="fa fa-exclamation-triangle"></i> Reach the limit</h4>
+                <h4 class="modal-title" id="myModalLabel"><i class="fa fa-exclamation-triangle"></i> <%= __('Reach the limit') %></h4>
             </div>
             <div class="modal-body" style="color:black;">
-                <h5>Sorry, you've reached the max length this note can be.</h5>
-                <strong>Please reduce the content or divide it to more notes, thank you!</strong>
+                <h5><%= __("Sorry, you've reached the max length this note can be.") %></h5>
+                <strong><%= __('Please reduce the content or divide it to more notes, thank you!') %></strong>
             </div>
             <div class="modal-footer">
-                <button type="button" class="btn btn-warning" data-dismiss="modal">OK</button>
+                <button type="button" class="btn btn-warning" data-dismiss="modal"><%= __('OK') %></button>
             </div>
         </div>
     </div>
@@ -107,7 +107,7 @@
                 <a target="_blank" style="word-break: break-all;"></a>
             </div>
             <div class="modal-footer">
-                <button type="button" class="btn btn-default" data-dismiss="modal">OK</button>
+                <button type="button" class="btn btn-default" data-dismiss="modal"><%= __('OK') %></button>
             </div>
         </div>
     </div>
@@ -119,15 +119,15 @@
             <div class="modal-header">
                 <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span>
                 </button>
-                <h4 class="modal-title" id="myModalLabel">Import from Gist</h4>
+                <h4 class="modal-title" id="myModalLabel"><%= __('Import from Gist') %></h4>
             </div>
             <div class="modal-body">
-                <input type="url" class="form-control" placeholder="Paste your gist url here... (like: https://gist.github.com/username/gistid)" id="gistImportModalContent">
+                <input type="url" class="form-control" placeholder="<%= __('Paste your gist url here...') %> (like: https://gist.github.com/username/gistid)" id="gistImportModalContent">
             </div>
             <div class="modal-footer">
-                <button type="button" class="btn btn-default" data-dismiss="modal">Cancel</button>
-                <button type="button" class="btn btn-danger" id="gistImportModalClear">Clear</button>
-                <button type="button" class="btn btn-primary" id="gistImportModalConfirm">Import</button>
+                <button type="button" class="btn btn-default" data-dismiss="modal"><%= __('Cancel') %></button>
+                <button type="button" class="btn btn-danger" id="gistImportModalClear"><%= __('Clear') %></button>
+                <button type="button" class="btn btn-primary" id="gistImportModalConfirm"><%= __('Import') %></button>
             </div>
         </div>
     </div>
@@ -139,7 +139,7 @@
             <div class="modal-header">
                 <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span>
                 </button>
-                <h4 class="modal-title" id="myModalLabel">Import from Snippet</h4>
+                <h4 class="modal-title" id="myModalLabel"><%= __('Import from Snippet') %></h4>
             </div>
             <div class="modal-body">
                 <input type="hidden" id="snippetImportModalAccessToken" />
@@ -148,24 +148,24 @@
                     <div style="display:table-row;margin-bottom:5px;">
                         <label style="display:table-cell;">Project:</label>
                         <select class="form-control" id="snippetImportModalProjects" style="display:table-cell;" disabled="disabled">
-                            <option value="init" selected="selected" disabled="disabled">Select From Available Projects</option>
+                            <option value="init" selected="selected" disabled="disabled"><%= __('Select From Available Projects') %></option>
                         </select>
                     </div>
                     <div style="display:table-row;">
                         <label style="display:table-cell;">Snippet</label>
                         <select class="form-control" id="snippetImportModalSnippets" style="display:table-cell;" disabled="disabled">
-                            <option value="init" selected="selected" disabled="disabled">Select From Available Snippets</option>
+                            <option value="init" selected="selected" disabled="disabled"><%= __('Select From Available Snippets') %></option>
                         </select>
                     </div>
                 </div>
-                <p class="snippet-import-or">OR</p>
+                <p class="snippet-import-or"><%= __('OR') %></p>
                 <input type="url" class="form-control" placeholder="/projects/:id/snippets/:snippet_id" id="snippetImportModalContent" disabled="disabled">
             </div>
             <div class="modal-footer">
                 <span id="snippetImportModalLoading"><i class="fa fa-refresh fa-spin fa-fw"></i></span>
-                <button type="button" class="btn btn-default" data-dismiss="modal">Cancel</button>
-                <button type="button" class="btn btn-danger" id="snippetImportModalClear">Clear</button>
-                <button type="button" class="btn btn-primary" id="snippetImportModalConfirm" disabled="disabled">Import</button>
+                <button type="button" class="btn btn-default" data-dismiss="modal"><%= __('Cancel') %></button>
+                <button type="button" class="btn btn-danger" id="snippetImportModalClear"><%= __('Clear') %></button>
+                <button type="button" class="btn btn-primary" id="snippetImportModalConfirm" disabled="disabled"><%= __('Import') %></button>
             </div>
         </div>
     </div>
@@ -177,7 +177,7 @@
             <div class="modal-header">
                 <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span>
                 </button>
-                <h4 class="modal-title" id="myModalLabel">Export to Snippet</h4>
+                <h4 class="modal-title" id="myModalLabel"><%= __('Export to Snippet') %></h4>
             </div>
             <div class="modal-body">
                 <input type="hidden" id="snippetExportModalAccessToken" />
@@ -194,13 +194,13 @@
                     <div style="display:table-row;margin-bottom:5px;">
                         <label style="display:table-cell;">Project:</label>
                         <select class="form-control" id="snippetExportModalProjects" style="display:table-cell;">
-                            <option value="init" selected="selected" disabled="disabled">Select From Available Projects</option>
+                            <option value="init" selected="selected" disabled="disabled"><%= __('Select From Available Projects') %></option>
                         </select>
                     </div>
                     <div style="display:table-row;margin-bottom:5px;">
                         <label style="display:table-cell;">Visibility:</label>
                         <select class="form-control" id="snippetExportModalVisibility" style="display:table-cell;">
-                            <option value="" selected="selected" disabled="disabled">Select Visibility Level</option>
+                            <option value="" selected="selected" disabled="disabled"><%= __('Select Visibility Level') %></option>
                             <option value="0">Private</option>
                             <option value="10">Internal</option>
                         </select>
@@ -209,8 +209,8 @@
             </div>
             <div class="modal-footer">
                 <span id="snippetExportModalLoading"><i class="fa fa-refresh fa-spin fa-fw"></i></span>
-                <button type="button" class="btn btn-default" data-dismiss="modal">Cancel</button>
-                <button type="button" class="btn btn-primary" id="snippetExportModalConfirm">Export</button>
+                <button type="button" class="btn btn-default" data-dismiss="modal"><%= __('Cancel') %></button>
+                <button type="button" class="btn btn-primary" id="snippetExportModalConfirm"><%= __('Export') %></button>
             </div>
         </div>
     </div>
diff --git a/public/views/header.ejs b/public/views/header.ejs
index 67760665..d2b1ec1e 100644
--- a/public/views/header.ejs
+++ b/public/views/header.ejs
@@ -22,18 +22,18 @@
                 <i class="fa fa-caret-down"></i>
             </a>
             <ul class="dropdown-menu list" role="menu" aria-labelledby="menu">
-                <li role="presentation"><a role="menuitem" class="ui-new" tabindex="-1" href="<%- url %>/new" target="_blank"><i class="fa fa-plus fa-fw"></i> New</a>
+                <li role="presentation"><a role="menuitem" class="ui-new" tabindex="-1" href="<%- url %>/new" target="_blank"><i class="fa fa-plus fa-fw"></i> <%= __('New') %></a>
                 </li>
-                <li role="presentation"><a role="menuitem" class="ui-publish" tabindex="-1" href="#" target="_blank"><i class="fa fa-print fa-fw"></i> Publish</a>
+                <li role="presentation"><a role="menuitem" class="ui-publish" tabindex="-1" href="#" target="_blank"><i class="fa fa-print fa-fw"></i> <%= __('Publish') %></a>
                 </li>
                 <li class="divider"></li>
-                <li class="dropdown-header">Extra</li>
-                <li role="presentation"><a role="menuitem" class="ui-extra-revision" tabindex="-1" data-toggle="modal" data-target="#revisionModal"><i class="fa fa-history fa-fw"></i> Revision</a>
+                <li class="dropdown-header"><%= __('Extra') %></li>
+                <li role="presentation"><a role="menuitem" class="ui-extra-revision" tabindex="-1" data-toggle="modal" data-target="#revisionModal"><i class="fa fa-history fa-fw"></i> <%= __('Revision') %></a>
                 </li>
-                <li role="presentation"><a role="menuitem" class="ui-extra-slide" tabindex="-1" href="#" target="_blank"><i class="fa fa-tv fa-fw"></i> Slide Mode</a>
+                <li role="presentation"><a role="menuitem" class="ui-extra-slide" tabindex="-1" href="#" target="_blank"><i class="fa fa-tv fa-fw"></i> <%= __('Slide Mode') %></a>
                 </li>
                 <li class="divider"></li>
-                <li class="dropdown-header">Export</li>
+                <li class="dropdown-header"><%= __('Export') %></li>
                 <li role="presentation"><a role="menuitem" class="ui-save-dropbox" tabindex="-1" href="#" target="_self"><i class="fa fa-dropbox fa-fw"></i> Dropbox</a>
                 </li>
                 <li role="presentation"><a role="menuitem" class="ui-save-google-drive" tabindex="-1" href="#" target="_self"><i class="fa fa-cloud-upload fa-fw"></i> Google Drive</a>
@@ -47,7 +47,7 @@
                 </li>
                 <% } %>
                 <li class="divider"></li>
-                <li class="dropdown-header">Import</li>
+                <li class="dropdown-header"><%= __('Import') %></li>
                 <li role="presentation"><a role="menuitem" class="ui-import-dropbox" tabindex="-1" href="#" target="_self"><i class="fa fa-dropbox fa-fw"></i> Dropbox</a>
                 </li>
                 <li role="presentation"><a role="menuitem" class="ui-import-google-drive" tabindex="-1" href="#" target="_self"><i class="fa fa-cloud-download fa-fw"></i> Google Drive</a>
@@ -58,15 +58,15 @@
                 <li role="presentation"><a role="menuitem" class="ui-import-snippet" href="#"><i class="fa fa-gitlab fa-fw"></i> Snippet</a>
                 </li>
                 <% } %>
-                <li role="presentation"><a role="menuitem" class="ui-import-clipboard" href="#" data-toggle="modal" data-target="#clipboardModal"><i class="fa fa-clipboard fa-fw"></i> Clipboard</a>
+                <li role="presentation"><a role="menuitem" class="ui-import-clipboard" href="#" data-toggle="modal" data-target="#clipboardModal"><i class="fa fa-clipboard fa-fw"></i> <%= __('Clipboard') %></a>
                 </li>
                 <li class="divider"></li>
-                <li class="dropdown-header">Download</li>
+                <li class="dropdown-header"><%= __('Download') %></li>
                 <li role="presentation"><a role="menuitem" class="ui-download-markdown" tabindex="-1" href="#" target="_self"><i class="fa fa-file-text fa-fw"></i> Markdown</a>
                 </li>
                 <li role="presentation"><a role="menuitem" class="ui-download-html" tabindex="-1" href="#" target="_self"><i class="fa fa-file-code-o fa-fw"></i> HTML</a>
                 </li>
-                <li role="presentation"><a role="menuitem" class="ui-download-raw-html" tabindex="-1" href="#" target="_self"><i class="fa fa-file-code-o fa-fw"></i> Raw HTML</a>
+                <li role="presentation"><a role="menuitem" class="ui-download-raw-html" tabindex="-1" href="#" target="_self"><i class="fa fa-file-code-o fa-fw"></i> <%= __('Raw HTML') %></a>
                 </li>
                 <li role="presentation"><a role="menuitem" class="ui-download-pdf-beta" tabindex="-1" href="#" target="_self"><i class="fa fa-file-pdf-o fa-fw"></i> PDF (Beta)</a>
                 </li>
@@ -82,20 +82,20 @@
     <div class="collapse navbar-collapse">
         <ul class="nav navbar-nav navbar-form navbar-left" style="padding:0;">
             <div class="btn-group" data-toggle="buttons">
-                <label class="btn btn-default ui-edit" title="Edit">
+                <label class="btn btn-default ui-edit" title="<%= __('Edit') %>">
                     <input type="radio" name="mode" autocomplete="off"><i class="fa fa-edit"></i>
                 </label>
-                <label class="btn btn-default ui-view" title="View">
+                <label class="btn btn-default ui-view" title="<%= __('View') %>">
                     <input type="radio" name="mode" autocomplete="off"><i class="fa fa-eye"></i>
                 </label>
-                <label class="btn btn-default ui-both" title="Both">
+                <label class="btn btn-default ui-both" title="<%= __('Both') %>">
                     <input type="radio" name="mode" autocomplete="off"><i class="fa fa-columns"></i>
                 </label>
             </div>
-            <span class="btn btn-link btn-file ui-help" title="Help" data-toggle="modal" data-target=".help-modal">
+            <span class="btn btn-link btn-file ui-help" title="<%= __('Help') %>" data-toggle="modal" data-target=".help-modal">
                 <i class="fa fa-question-circle"></i>
             </span>
-            <span class="btn btn-link btn-file ui-upload-image" title="Upload Image" style="display:none;">
+            <span class="btn btn-link btn-file ui-upload-image" title="<%= __('Upload Image') %>" style="display:none;">
                 <i class="fa fa-camera"></i><input type="file" accept="image/*" name="upload" multiple>
             </span>
         </ul>
@@ -111,26 +111,26 @@
         <ul class="nav navbar-nav navbar-right" style="padding:0;">
             <li>
                 <a href="<%- url %>/new" target="_blank" class="ui-new">
-                    <i class="fa fa-plus"></i> New
+                    <i class="fa fa-plus"></i> <%= __('New') %>
                 </a>
             </li>
             <li>
                 <a href="#" target="_blank" class="ui-publish">
-                    <i class="fa fa-print"></i> Publish
+                    <i class="fa fa-print"></i> <%= __('Publish') %>
                 </a>
             </li>
             <li>
                 <a data-toggle="dropdown">
-                    Menu <i class="fa fa-caret-down"></i>
+                    <%= __('Menu') %> <i class="fa fa-caret-down"></i>
                 </a>
                 <ul class="dropdown-menu list" role="menu" aria-labelledby="menu">
-                    <li class="dropdown-header">Extra</li>
-                    <li role="presentation"><a role="menuitem" class="ui-extra-revision" tabindex="-1" data-toggle="modal" data-target="#revisionModal"><i class="fa fa-history fa-fw"></i> Revision</a>
+                    <li class="dropdown-header"><%= __('Extra') %></li>
+                    <li role="presentation"><a role="menuitem" class="ui-extra-revision" tabindex="-1" data-toggle="modal" data-target="#revisionModal"><i class="fa fa-history fa-fw"></i> <%= __('Revision') %></a>
                     </li>
-                    <li role="presentation"><a role="menuitem" class="ui-extra-slide" tabindex="-1" href="#" target="_blank"><i class="fa fa-tv fa-fw"></i> Slide Mode</a>
+                    <li role="presentation"><a role="menuitem" class="ui-extra-slide" tabindex="-1" href="#" target="_blank"><i class="fa fa-tv fa-fw"></i> <%= __('Slide Mode') %></a>
                     </li>
                     <li class="divider"></li>
-                    <li class="dropdown-header">Export</li>
+                    <li class="dropdown-header"><%= __('Export') %></li>
                     <li role="presentation"><a role="menuitem" class="ui-save-dropbox" tabindex="-1" href="#" target="_self"><i class="fa fa-dropbox fa-fw"></i> Dropbox</a>
                     </li>
                     <li role="presentation"><a role="menuitem" class="ui-save-google-drive" tabindex="-1" href="#" target="_self"><i class="fa fa-cloud-upload fa-fw"></i> Google Drive</a>
@@ -144,7 +144,7 @@
                     </li>
                     <% } %>
                     <li class="divider"></li>
-                    <li class="dropdown-header">Import</li>
+                    <li class="dropdown-header"><%= __('Import') %></li>
                     <li role="presentation"><a role="menuitem" class="ui-import-dropbox" tabindex="-1" href="#" target="_self"><i class="fa fa-dropbox fa-fw"></i> Dropbox</a>
                     </li>
                     <li role="presentation"><a role="menuitem" class="ui-import-google-drive" tabindex="-1" href="#" target="_self"><i class="fa fa-cloud-download fa-fw"></i> Google Drive</a>
@@ -155,15 +155,15 @@
                     <li role="presentation"><a role="menuitem" class="ui-import-snippet" href="#"><i class="fa fa-gitlab fa-fw"></i> Snippet</a>
                     </li>
                     <% } %>
-                    <li role="presentation"><a role="menuitem" class="ui-import-clipboard" href="#" data-toggle="modal" data-target="#clipboardModal"><i class="fa fa-clipboard fa-fw"></i> Clipboard</a>
+                    <li role="presentation"><a role="menuitem" class="ui-import-clipboard" href="#" data-toggle="modal" data-target="#clipboardModal"><i class="fa fa-clipboard fa-fw"></i> <%= __('Clipboard') %></a>
                     </li>
                     <li class="divider"></li>
-                    <li class="dropdown-header">Download</li>
+                    <li class="dropdown-header"><%= __('Download') %></li>
                     <li role="presentation"><a role="menuitem" class="ui-download-markdown" tabindex="-1" href="#" target="_self"><i class="fa fa-file-text fa-fw"></i> Markdown</a>
                     </li>
                     <li role="presentation"><a role="menuitem" class="ui-download-html" tabindex="-1" href="#" target="_self"><i class="fa fa-file-code-o fa-fw"></i> HTML</a>
                     </li>
-                    <li role="presentation"><a role="menuitem" class="ui-download-raw-html" tabindex="-1" href="#" target="_self"><i class="fa fa-file-code-o fa-fw"></i> Raw HTML</a>
+                    <li role="presentation"><a role="menuitem" class="ui-download-raw-html" tabindex="-1" href="#" target="_self"><i class="fa fa-file-code-o fa-fw"></i> <%= __('Raw HTML') %></a>
                     </li>
                     <li role="presentation"><a role="menuitem" class="ui-download-pdf-beta" tabindex="-1" href="#" target="_self"><i class="fa fa-file-pdf-o fa-fw"></i> PDF (Beta)</a>
                     </li>
diff --git a/public/views/help-modal.ejs b/public/views/help-modal.ejs
index 3a4fe22b..3d119e8b 100644
--- a/public/views/help-modal.ejs
+++ b/public/views/help-modal.ejs
@@ -5,79 +5,79 @@
             <div class="modal-header">
                 <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span>
                 </button>
-                <h4 class="modal-title" id="mySmallModalLabel"><i class="fa fa-question-circle"></i> Help</h4>
+                <h4 class="modal-title" id="mySmallModalLabel"><i class="fa fa-question-circle"></i> <%= __('Help') %></h4>
             </div>
             <div class="modal-body">
                 <div class="row">
                     <div class="col-lg-3">
                         <div class="panel panel-default">
                             <div class="panel-heading">
-                                <h3 class="panel-title">Contacts</h3>
+                                <h3 class="panel-title"><%= __('Contacts') %></h3>
                             </div>
                             <div class="panel-body">
-                                <a href="https://github.com/hackmdio/hackmd/issues" title="Report an issue" target="_blank"><i class="fa fa-tag fa-fw"></i> Report an issue</a> 
+                                <a href="https://github.com/hackmdio/hackmd/issues" target="_blank"><i class="fa fa-tag fa-fw"></i> <%= __('Report an issue') %></a> 
                                 <br>
-                                <a href="mailto:hackmdio@gmail.com" title="Send us email"><i class="fa fa-envelope fa-fw"></i> Send us email</a>
+                                <a href="mailto:hackmdio@gmail.com"><i class="fa fa-envelope fa-fw"></i> <%= __('Send us email') %></a>
                             </div>
                         </div>
                         <div class="panel panel-default">
                             <div class="panel-heading">
-                                <h3 class="panel-title">Documents</h3>
+                                <h3 class="panel-title"><%= __('Documents') %></h3>
                             </div>
                             <div class="panel-body">
-                                <a href="./features" title="Features" target="_blank"><i class="fa fa-dot-circle-o fa-fw"></i> Features</a>
+                                <a href="./features" title="Features" target="_blank"><i class="fa fa-dot-circle-o fa-fw"></i> <%= __('Features') %></a>
                                 <br>
-                                <a href="./yaml-metadata" title="YAML Metadata" target="_blank"><i class="fa fa-dot-circle-o fa-fw"></i> YAML Metadata</a>
+                                <a href="./yaml-metadata" title="YAML Metadata" target="_blank"><i class="fa fa-dot-circle-o fa-fw"></i> <%= __('YAML Metadata') %></a>
                                 <br>
-                                <a href="./slide-example" title="Slide Example" target="_blank"><i class="fa fa-dot-circle-o fa-fw"></i> Slide Example</a>
+                                <a href="./slide-example" title="Slide Example" target="_blank"><i class="fa fa-dot-circle-o fa-fw"></i> <%= __('Slide Example') %></a>
                             </div>
                         </div>
                     </div>
                     <div class="col-lg-9">
                         <div class="panel panel-default">
                             <div class="panel-heading">
-                                <h3 class="panel-title">Cheatsheet</h3>
+                                <h3 class="panel-title"><%= __('Cheatsheet') %></h3>
                             </div>
                             <div class="panel-body" style="height: calc(100vh - 215px); overflow: auto;">
                                 <table class="table table-condensed">
                                     <thead>
                                         <tr>
-                                            <th>Example</th>
-                                            <th>Syntax</th>
+                                            <th><%= __('Example') %></th>
+                                            <th><%= __('Syntax') %></th>
                                         </tr>
                                     </thead>
                                     <tbody class="markdown-body" style="font-family: inherit; font-size: 14px; padding: 0; max-width: inherit;">
                                         <tr>
-                                            <td>Header</td>
-                                            <td># Header</td>
+                                            <td><%= __('Header') %></td>
+                                            <td># <%= __('Header') %></td>
                                         </tr>
                                         <tr>
-                                            <td><ul><li>Unordered List</li></ul></td>
-                                            <td>- Unordered List</td>
+                                            <td><ul><li><%= __('Unordered List') %></li></ul></td>
+                                            <td>- <%= __('Unordered List') %></td>
                                         </tr>
                                         <tr>
-                                            <td><ol><li>Ordered List</li></ol></td>
-                                            <td>1. Ordered List</td>
+                                            <td><ol><li><%= __('Ordered List') %></li></ol></td>
+                                            <td>1. <%= __('Ordered List') %></td>
                                         </tr>
                                         <tr>
-                                            <td><ul><li class="task-list-item"><input type="checkbox" class="task-list-item-checkbox" disabled><label></label>Todo List</li></ul></td>
-                                            <td>- [ ] Todo List</td>
+                                            <td><ul><li class="task-list-item"><input type="checkbox" class="task-list-item-checkbox" disabled><label></label><%= __('Todo List') %></li></ul></td>
+                                            <td>- [ ] <%= __('Todo List') %></td>
                                         </tr>
                                         <tr>
-                                            <td><blockquote> Blockquote</blockquote></td>
-                                            <td>> Blockquote</td>
+                                            <td><blockquote> <%= __('Blockquote') %></blockquote></td>
+                                            <td>> <%= __('Blockquote') %></td>
                                         </tr>
                                         <tr>
-                                            <td><strong>Bold font</strong></td>
-                                            <td>**Bold font**</td>
+                                            <td><strong><%= __('Bold font') %></strong></td>
+                                            <td>**<%= __('Bold font') %>**</td>
                                         </tr>
                                         <tr>
-                                            <td><i>Italics font</i></td>
-                                            <td>*Italics font*</td>
+                                            <td><i><%= __('Italics font') %></i></td>
+                                            <td>*<%= __('Italics font') %>*</td>
                                         </tr>
                                         <tr>
-                                            <td><s>Strikethrough</s></td>
-                                            <td>~~strikethrough~~</td>
+                                            <td><s><%= __('Strikethrough') %></s></td>
+                                            <td>~~<%= __('Strikethrough') %>~~</td>
                                         </tr>
                                         <tr>
                                             <td>19<sup>th</sup></td>
@@ -88,24 +88,24 @@
                                             <td>H~2~O</td>
                                         </tr>
                                         <tr>
-                                            <td><ins>Inserted text</ins></td>
-                                            <td>++Inserted text++</td>
+                                            <td><ins><%= __('Inserted text') %></ins></td>
+                                            <td>++<%= __('Inserted text') %>++</td>
                                         </tr>
                                         <tr>
-                                            <td><mark>Marked text</mark></td>
-                                            <td>==Marked text==</td>
+                                            <td><mark><%= __('Marked text') %></mark></td>
+                                            <td>==<%= __('Marked text') %>==</td>
                                         </tr>
                                         <tr>
-                                            <td><a>Link</a></td>
+                                            <td><a><%= __('Link') %></a></td>
                                             <td>[link text](https:// "title")</td>
                                         </tr>
                                         <tr>
-                                            <td>Image</td>
+                                            <td><%= __('Image') %></td>
                                             <td>![image alt](https:// "title")</td>
                                         </tr>
                                         <tr>
-                                            <td><code>Code</code></td>
-                                            <td>`code`</td>
+                                            <td><code><%= __('Code') %></code></td>
+                                            <td>`<%= __('Code') %>`</td>
                                         </tr>
                                         <tr>
                                             <td><pre style="border:none !important;"><code class="javascript hljs"><div class="wrapper"><div class="gutter linenumber"><span data-linenumber="1"></span></div><div class="code"><span class="hljs-keyword">var</span> i = <span class="hljs-number">0</span>;
@@ -117,7 +117,7 @@
                                             <td>:smile:</td>
                                         </tr>
                                         <tr>
-                                            <td>Externals</td>
+                                            <td><%= __('Externals') %></td>
                                             <td>{%youtube youtube_id %}</td>
                                         </tr>
                                         <tr>
@@ -125,8 +125,8 @@
                                             <td>$L^aT_eX$</td>
                                         </tr>
                                         <tr>
-                                            <td><div class="alert alert-info"><p>This is a alert area.</p></div></td>
-                                            <td>:::info<br>This is a alert area.<br>:::</td>
+                                            <td><div class="alert alert-info"><p><%= __('This is a alert area.') %></p></div></td>
+                                            <td>:::info<br><%= __('This is a alert area.') %><br>:::</td>
                                         </tr>
                                     </tbody>
                                 </table>
diff --git a/public/views/index.ejs b/public/views/index.ejs
index daf123b1..8c4cf101 100644
--- a/public/views/index.ejs
+++ b/public/views/index.ejs
@@ -8,9 +8,9 @@
     <meta name="apple-mobile-web-app-capable" content="yes">
     <meta name="apple-mobile-web-app-status-bar-style" content="black">
     <meta name="mobile-web-app-capable" content="yes">
-    <meta name="description" content="Best way to write and share your knowledge in markdown.">
+    <meta name="description" content="<%= __('Best way to write and share your knowledge in markdown.') %>">
     <meta name="keywords" content="Collaborative, Markdown, Notes">
-    <title>HackMD - Collaborative markdown notes</title>
+    <title>HackMD - <%= __('Collaborative markdown notes') %></title>
     <link rel="icon" type="image/png" href="<%- url %>/favicon.png">
     <link rel="apple-touch-icon" href="<%- url %>/apple-touch-icon.png">
 
@@ -41,9 +41,9 @@
                         <h3 class="masthead-brand"></h3>
                         <nav>
                             <ul class="nav masthead-nav">
-                                <li class="ui-home<% if(!signin) { %> active<% } %>"><a href="#">Intro</a>
+                                <li class="ui-home<% if(!signin) { %> active<% } %>"><a href="#"><%= __('Intro') %></a>
                                 </li>
-                                <li class="ui-history<% if(signin) { %> active<% } %>"><a href="#">History</a>
+                                <li class="ui-history<% if(signin) { %> active<% } %>"><a href="#"><%= __('History') %></a>
                                 </li>
                             </ul>
                         </nav>
@@ -54,17 +54,17 @@
                     <div class="inner cover">
                         <h1 class="cover-heading"><i class="fa fa-file-text"></i> HackMD</h1>
                         <p class="lead">
-                            Best way to write and share your knowledge in markdown.
+                            <%= __('Best way to write and share your knowledge in markdown.') %>
                         </p>
                         <% if(facebook || twitter || github || gitlab || dropbox || google) { %>
                         <span class="ui-signin">
                             <br>
-                            <a type="button" class="btn btn-lg btn-success ui-signin" data-toggle="modal" data-target=".signin-modal" style="width: 170px;">Sign In</a>
+                            <a type="button" class="btn btn-lg btn-success ui-signin" data-toggle="modal" data-target=".signin-modal" style="width: 170px;"><%= __('Sign In') %></a>
                         </span>
-                        <span class="ui-or">or</span>
+                        <span class="ui-or"><%= __('or') %></span>
                         <% }%>
                         <span class="ui-signin">
-                            <a href="<%- url %>/new" class="btn btn-lg btn-default" style="width: 170px;">New guest note</a>
+                            <a href="<%- url %>/new" class="btn btn-lg btn-default" style="width: 170px;"><%= __('New guest note') %></a>
                             <br>
                             <br>
                         </span>
@@ -72,19 +72,19 @@
                             <div class="col-md-4 inner">
                                 <a href="<%- url %>/features#share-note">
                                     <i class="fa fa-bolt fa-3x"></i>
-                                    <h4>Collaborate with URL</h4>
+                                    <h4><%= __('Collaborate with URL') %></h4>
                                 </a>
                             </div>
                             <div class="col-md-4 inner">
                                 <a href="<%- url %>/features#mathjax">
                                     <i class="fa fa-bar-chart fa-3x"></i>
-                                    <h4>Support charts and MathJax</h4>
+                                    <h4><%= __('Support charts and MathJax') %></h4>
                                 </a>
                             </div>
                             <div class="col-md-4 inner">
                                 <a href="<%- url %>/features#slide-mode">
                                     <i class="fa fa-tv fa-3x"></i>
-                                    <h4>Support slide mode</h4>
+                                    <h4><%= __('Support slide mode') %></h4>
                                 </a>
                             </div>
                         </div>
@@ -94,45 +94,45 @@
                 <div id="history" class="section"<% if(!signin) { %> style="display:none;"<% } %>>
                     <% if(facebook || twitter || github || gitlab || dropbox || google) { %>
                     <div class="ui-signin">
-                        <p>Below is the history from browser</p>
+                        <p><%= __('Below is the history from browser') %></p>
                     </div>
                     <div class="ui-signout" style="display:none;">
                         <img class="ui-avatar">
-                        <h4 class="ui-welcome">Welcome! <span class="ui-name"></span></h4>
-                        <a href="<%- url %>/new" class="btn btn-md btn-default">New note</a> or
-                        <a href="#" class="btn btn-danger ui-logout">Sign Out</a>
+                        <h4 class="ui-welcome"><%= __('Welcome!') %> <span class="ui-name"></span></h4>
+                        <a href="<%- url %>/new" class="btn btn-md btn-default"><%= __('New note') %></a> <%= __('or') %>
+                        <a href="#" class="btn btn-danger ui-logout"><%= __('Sign Out') %></a>
                     </div>
                     <% }%>
                     <h4>
-                        <a type="button" href="<%- url %>/features" class="btn btn-primary">Explore all features</a>
+                        <a type="button" href="<%- url %>/features" class="btn btn-primary"><%= __('Explore all features') %></a>
                     </h4>
                     <hr>
                     <form class="form-inline">
                         <div class="form-group" style="vertical-align: bottom;">
-                            <input class="form-control ui-use-tags" />
+                            <input class="form-control ui-use-tags" placeholder="<%= __('Select tags...') %>" />
                         </div>
                         <div class="form-group">
-                            <input class="search form-control" placeholder="Search keyword..." />
+                            <input class="search form-control" placeholder="<%= __('Search keyword...') %>" />
                         </div>
-                        <a href="#" class="sort btn btn-default" data-sort="text" title="Sort by title">
-                        Title
+                        <a href="#" class="sort btn btn-default" data-sort="text" title="<%= __('Sort by title') %>">
+                        <%= __('Title') %>
                         </a>
-                        <a href="#" class="sort btn btn-default" data-sort="timestamp" title="Sort by time">
-                        Time
+                        <a href="#" class="sort btn btn-default" data-sort="timestamp" title="<%= __('Sort by time') %>">
+                        <%= __('Time') %>
                         </a>
                         <span class="hidden-xs hidden-sm">
-                            <a href="#" class="btn btn-default ui-save-history" title="Export history"><i class="fa fa-save"></i></a>
-                            <span class="btn btn-default btn-file ui-open-history" title="Import history">
+                            <a href="#" class="btn btn-default ui-save-history" title="<%= __('Export history') %>"><i class="fa fa-save"></i></a>
+                            <span class="btn btn-default btn-file ui-open-history" title="<%= __('Import history') %>">
                                 <i class="fa fa-folder-open-o"></i><input type="file" />
                             </span>
-                        <a href="#" class="btn btn-default ui-clear-history" title="Clear history" data-toggle="modal" data-target=".delete-modal"><i class="fa fa-trash-o"></i></a>
+                        <a href="#" class="btn btn-default ui-clear-history" title="<%= __('Clear history') %>" data-toggle="modal" data-target=".delete-modal"><i class="fa fa-trash-o"></i></a>
                         </span>
-                        <a href="#" class="btn btn-default ui-refresh-history" title="Refresh history"><i class="fa fa-refresh"></i></a>
+                        <a href="#" class="btn btn-default ui-refresh-history" title="<%= __('Refresh history') %>"><i class="fa fa-refresh"></i></a>
                     </form>
                     <h4 class="ui-nohistory" style="display:none;">
-                        No history
+                        <%= __('No history') %>
                     </h4>
-                    <a href="#" class="btn btn-primary ui-import-from-browser" style="display:none;">Import from browser</a>
+                    <a href="#" class="btn btn-primary ui-import-from-browser" style="display:none;"><%= __('Import from browser') %></a>
                     <ul id="history-list" class="list">
                     </ul>
                 </div>
@@ -143,8 +143,12 @@
                             <iframe src="//ghbtns.com/github-btn.html?user=hackmdio&repo=hackmd&type=star&count=true" frameborder="0" scrolling="0" width="90px" height="20px"></iframe>
                         </h6>
                         <p>
-                            &copy; 2016 <a href="https://www.facebook.com/TakeHackMD" target="_blank"><i class="fa fa-facebook-square"></i> HackMD</a> | <a href="<%- url %>/s/release-notes" target="_blank">Releases</a>
+                            &copy; 2016 <a href="https://www.facebook.com/TakeHackMD" target="_blank"><i class="fa fa-facebook-square"></i> HackMD</a> | <a href="<%- url %>/s/release-notes" target="_blank"><%= __('Releases') %></a>
                         </p>
+                        <select class="ui-locale">
+                            <option value="en">English</option>
+                            <option value="zh">中文</option>
+                        </select>
                     </div>
                 </div>
             </div>
@@ -157,15 +161,15 @@
                 <div class="modal-header">
                     <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span>
                     </button>
-                    <h4 class="modal-title" id="myModalLabel">Are you sure?</h4>
+                    <h4 class="modal-title" id="myModalLabel"><%= __('Are you sure?') %></h4>
                 </div>
                 <div class="modal-body" style="color:black;">
                     <h5 class="ui-delete-modal-msg"></h5>
                     <strong class="ui-delete-modal-item"></strong>
                 </div>
                 <div class="modal-footer">
-                    <button type="button" class="btn btn-default" data-dismiss="modal">Cancel</button>
-                    <button type="button" class="btn btn-danger ui-delete-modal-confirm">Yes, do it!</button>
+                    <button type="button" class="btn btn-default" data-dismiss="modal"><%= __('Cancel') %></button>
+                    <button type="button" class="btn btn-danger ui-delete-modal-confirm"><%= __('Yes, do it!') %></button>
                 </div>
             </div>
         </div>
@@ -198,6 +202,7 @@
     <script src="<%- url %>/js/common.js" defer></script>
     <script src="<%- url %>/js/history.js" defer></script>
     <script src="<%- url %>/js/cover.js" defer></script>
+    <script src="<%- url %>/js/locale.js" defer></script>
 </body>
 
 </html>
diff --git a/public/views/refresh-modal.ejs b/public/views/refresh-modal.ejs
index 07e3ecab..5be41b2a 100644
--- a/public/views/refresh-modal.ejs
+++ b/public/views/refresh-modal.ejs
@@ -5,26 +5,26 @@
             <div class="modal-header">
                 <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span>
                 </button>
-                <h4 class="modal-title" id="myModalLabel">This page need refresh</h4>
+                <h4 class="modal-title" id="myModalLabel"><%= __('This page need refresh') %></h4>
             </div>
             <div class="modal-body">
                 <div class="incompatible-version">
-                    <h5>You have an incompatible client version.</h5>
-                    <strong>Refresh to update.</strong>
+                    <h5><%= __('You have an incompatible client version.') %></h5>
+                    <strong><%= __('Refresh to update.') %></strong>
                 </div>
                 <div class="new-version" style="display:none;">
-                    <h5>New version available!</h5>
-                    <a href="<%- url %>/s/release-notes" target="_blank">See releases notes here</a>
+                    <h5><%= __('New version available!') %></h5>
+                    <a href="<%- url %>/s/release-notes" target="_blank"><%= __('See releases notes here') %></a>
                     <br>
-                    <strong>Refresh to enjoy new features.</strong>
+                    <strong><%= __('Refresh to enjoy new features.') %></strong>
                 </div>
                 <div class="user-state-changed" style="display:none;">
-                    <h5>Your user state has changed.</h5>
-                    <strong>Refresh to load new user state.</strong>
+                    <h5><%= __('Your user state has changed.') %></h5>
+                    <strong><%= __('Refresh to load new user state.') %></strong>
                 </div>
             </div>
             <div class="modal-footer">
-                <button type="button" class="btn btn-primary" id="refreshModalRefresh">Refresh</button>
+                <button type="button" class="btn btn-primary" id="refreshModalRefresh"><%= __('Refresh') %></button>
             </div>
         </div>
     </div>
diff --git a/public/views/revision-modal.ejs b/public/views/revision-modal.ejs
index 008e62ac..f824cf06 100644
--- a/public/views/revision-modal.ejs
+++ b/public/views/revision-modal.ejs
@@ -5,7 +5,7 @@
             <div class="modal-header">
                 <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span>
                 </button>
-                <h4 class="modal-title" id="mySmallModalLabel"><i class="fa fa-history"></i> Revision</h4>
+                <h4 class="modal-title" id="mySmallModalLabel"><i class="fa fa-history"></i> <%= __('Revision') %></h4>
             </div>
             <div class="modal-body">
                 <div class="row">
@@ -18,9 +18,9 @@
                 </div>
             </div>
             <div class="modal-footer">
-                <button type="button" class="btn btn-default" data-dismiss="modal">Cancel</button>
-                <button type="button" class="btn btn-primary" id="revisionModalDownload">Download</button>
-                <button type="button" class="btn btn-danger" id="revisionModalRevert">Revert</button>
+                <button type="button" class="btn btn-default" data-dismiss="modal"><%= __('Cancel') %></button>
+                <button type="button" class="btn btn-primary" id="revisionModalDownload"><%= __('Download') %></button>
+                <button type="button" class="btn btn-danger" id="revisionModalRevert"><%= __('Revert') %></button>
             </div>
         </div>
     </div>
diff --git a/public/views/signin-modal.ejs b/public/views/signin-modal.ejs
index 293480b9..a3ca63f8 100644
--- a/public/views/signin-modal.ejs
+++ b/public/views/signin-modal.ejs
@@ -5,37 +5,37 @@
             <div class="modal-header">
                 <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span>
                 </button>
-                <h4 class="modal-title" id="mySmallModalLabel">Choose method</h4>
+                <h4 class="modal-title" id="mySmallModalLabel"><%= __('Choose method') %></h4>
             </div>
             <div class="modal-body">
                 <% if(facebook) { %>
                 <a href="<%- url %>/auth/facebook" class="btn btn-lg btn-block btn-social btn-facebook">
-                    <i class="fa fa-facebook"></i> Sign in via Facebook
+                    <i class="fa fa-facebook"></i> <%= __('Sign in via %s', 'Facebook') %>
                 </a>
                 <% } %>
                 <% if(twitter) { %>
                 <a href="<%- url %>/auth/twitter" class="btn btn-lg btn-block btn-social btn-twitter">
-                    <i class="fa fa-twitter"></i> Sign in via Twitter
+                    <i class="fa fa-twitter"></i> <%= __('Sign in via %s', 'Twitter') %>
                 </a>
                 <% } %>
                 <% if(github) { %>
                 <a href="<%- url %>/auth/github" class="btn btn-lg btn-block btn-social btn-github">
-                    <i class="fa fa-github"></i> Sign in via GitHub
+                    <i class="fa fa-github"></i> <%= __('Sign in via %s', 'GitHub') %>
                 </a>
                 <% } %>
                 <% if(gitlab) { %>
                 <a href="<%- url %>/auth/gitlab" class="btn btn-lg btn-block btn-social btn-soundcloud">
-                    <i class="fa fa-gitlab"></i> Sign in via GitLab
+                    <i class="fa fa-gitlab"></i> <%= __('Sign in via %s', 'GitLab') %>
                 </a>
                 <% } %>
                 <% if(dropbox) { %>
                 <a href="<%- url %>/auth/dropbox" class="btn btn-lg btn-block btn-social btn-dropbox">
-                    <i class="fa fa-dropbox"></i> Sign in via Dropbox
+                    <i class="fa fa-dropbox"></i> <%= __('Sign in via %s', 'Dropbox') %>
                 </a>
                 <% } %>
                 <% if(google) { %>
                 <a href="<%- url %>/auth/google" class="btn btn-lg btn-block btn-social btn-google">
-                    <i class="fa fa-google"></i> Sign in via Google
+                    <i class="fa fa-google"></i> <%= __('Sign in via %s', 'Google') %>
                 </a>
                 <% } %>
             </div>