Better blockquote button in Markdown editor when non-traditional markdown linebreaks

are enabled.

app/assets/javascripts/pagedown_custom.js

@@ -10,5 +10,29 @@ window.PagedownCustom = {
         return Discourse.__container__.lookup('controller:composer').send('importQuote');
       }
     }
-  ]
+  ],
+
+  customActions: {
+    "doBlockquote": function(chunk, postProcessing, oldDoBlockquote) {
+
+      // When traditional linebreaks are set, use the default Pagedown implementation
+      if (Discourse.SiteSettings.traditional_markdown_linebreaks) {
+        return oldDoBlockquote.call(this, chunk, postProcessing);
+      }
+
+      // Our custom blockquote for non-traditional markdown linebreaks
+      var result = [];
+      chunk.selection.split(/\n/).forEach(function (line) {
+        var newLine = "";
+        if (line.indexOf("> ") === 0) {
+          newLine += line.substr(2);
+        } else {
+          if (/\S/.test(line)) { newLine += "> " + line; }
+        }
+        result.push(newLine)
+      })
+      chunk.selection = result.join("\n");
+
+    }
+  }
 };

vendor/assets/javascripts/Markdown.Editor.js

@@ -18,6 +18,17 @@
 //        ]
 //      };
 //
+// To extend actions:
+//
+//      window.PagedownCustom = {
+//          customActions: {
+//             "doBlockquote": function(chunk, postProcessing, oldDoBlockquote) {
+//               console.log('custom blockquote called!');
+//               return oldDoBlockquote.call(this, chunk, postProcessing);
+//             }
+//          }
+//      };
+
 
 (function () {
 
@@ -1470,6 +1481,17 @@
         }
 
         function bindCommand(method) {
+            if (typeof PagedownCustom != "undefined" && PagedownCustom.customActions) {
+                var custom = PagedownCustom.customActions[method];
+                if (custom) {
+                    return function() {
+                        var args = Array.prototype.slice.call(arguments);
+                        args.push(commandManager[method]);
+                        return custom.apply(commandManager, args);
+                    };
+                }
+            }
+
             if (typeof method === "string")
                 method = commandManager[method];
             return function () { method.apply(commandManager, arguments); }