Reuse Lib.counterRegex to match deprecated title string attributes [882]

- Add `matchBeginning` parameter to `regex.counter`.

Author: rmoestl

src/lib/regex.js

@@ -16,11 +16,13 @@
  * @param {Optional(string)} tail: a fixed piece after the id
  *      eg counterRegex('scene', '.annotations') for scene2.annotations etc.
  * @param {boolean} openEnded: if true, the string may continue past the match.
+ * @param {boolean} matchBeginning: if false, the string may start before the match.
  */
-exports.counter = function(head, tail, openEnded) {
+exports.counter = function(head, tail, openEnded, matchBeginning) {
     var fullTail = (tail || '') + (openEnded ? '' : '$');
+    var startWithPrefix = matchBeginning === false ? '' : '^';
     if(head === 'xy') {
-        return new RegExp('^x([2-9]|[1-9][0-9]+)?y([2-9]|[1-9][0-9]+)?' + fullTail);
+        return new RegExp(startWithPrefix + 'x([2-9]|[1-9][0-9]+)?y([2-9]|[1-9][0-9]+)?' + fullTail);
     }
-    return new RegExp('^' + head + '([2-9]|[1-9][0-9]+)?' + fullTail);
+    return new RegExp(startWithPrefix + head + '([2-9]|[1-9][0-9]+)?' + fullTail);
 };

src/plot_api/plot_api.js

@@ -1700,7 +1700,7 @@ function _restyle(gd, aobj, traces) {
  * @param layoutObj
  */
 function cleanDeprecatedLayoutAttributes(layoutObj) {
-    var oldAxisTitleRegExp = /axis\d{0,2}\.title$/;
+    var oldAxisTitleRegExp = Lib.counterRegex('axis', '\.title', false, false);
     var keys, i, key, value;
 
     if(typeof layoutObj.title === 'string') {