Adding "preserve" to attributeCheckMethods

parser_rules/advanced.js

@@ -99,7 +99,8 @@ var wysihtml5ParserRules = {
      *                            - src:            allows something like "/foobar.jpg", "http://google.com", ...
      *                            - href:           allows something like "mailto:[email protected]", "http://google.com", "/foobar.jpg"
      *                            - alt:            strips unwanted characters. if the attribute is not set, then it gets set (to ensure valid and compatible HTML)
-     *                            - numbers:  ensures that the attribute only contains numeric characters
+     *                            - numbers:        ensures that the attribute only contains numeric characters
+     *                            - preserve:       keep the current value in the property.
      */
     "tags": {
         "tr": {
@@ -180,11 +181,11 @@ var wysihtml5ParserRules = {
         },
         "a": {
             "check_attributes": {
+                "target": "preserve", // If a user specifies a target, we should keep it that way.
                 "href": "url" // if you compiled master manually then change this from 'url' to 'href'
             },
             "set_attributes": {
                 "rel": "nofollow",
-                "target": "_blank"
             }
         },
         "img": {

parser_rules/simple.js

@@ -21,10 +21,10 @@ var wysihtml5ParserRules = {
     li:     {},
     a:      {
       set_attributes: {
-        target: "_blank",
         rel:    "nofollow"
       },
       check_attributes: {
+        target: "preserve", // If a user specifies a target, we should keep it that way.
         href:   "url" // important to avoid XSS
       }
     }

src/dom/parse.js

@@ -423,6 +423,12 @@ wysihtml5.dom.parse = (function() {
         attributeValue = (attributeValue || "").replace(REG_EXP, "");
         return attributeValue || null;
       };
+    })(),
+
+    preserve: (function() {
+      return function(attributeValue) {
+        return attributeValue;
+      };
     })()
   };