feat(dateparser): allow overriding of parsers

- Add ability to override parser

Closes #6370
Closes #6373

src/dateparser/dateparser.js

@@ -1,6 +1,6 @@
 angular.module('ui.bootstrap.dateparser', [])
 
-.service('uibDateParser', ['$log', '$locale', 'dateFilter', 'orderByFilter', function($log, $locale, dateFilter, orderByFilter) {
+.service('uibDateParser', ['$log', '$locale', 'dateFilter', 'orderByFilter', 'filterFilter', function($log, $locale, dateFilter, orderByFilter, filterFilter) {
   // Pulled from https://github.com/mbostock/d3/blob/master/src/format/requote.js
   var SPECIAL_CHARACTERS_REGEXP = /[\\\^\$\*\+\?\|\[\]\(\)\.\{\}]/g;
 
@@ -243,6 +243,23 @@ angular.module('ui.bootstrap.dateparser', [])
 
   this.init();
 
+  function getFormatCodeToRegex(key) {
+    return filterFilter(formatCodeToRegex, {key: key}, true)[0];
+  }
+
+  this.getParser = function (key) {
+    var f = getFormatCodeToRegex(key);
+    return f && f.apply || null;
+  };
+
+  this.overrideParser = function (key, parser) {
+    var f = getFormatCodeToRegex(key);
+    if (f && angular.isFunction(parser)) {
+      this.parsers = {};
+      f.apply = parser;
+    }
+  }.bind(this);
+
   function createParser(format) {
     var map = [], regex = format.split('');
 

src/dateparser/test/dateparser.spec.js

@@ -791,4 +791,28 @@ describe('date parser', function() {
       });
     });
   });
+
+  describe('overrideParser', function() {
+    var twoDigitYearParser = function (value) {
+      this.year = +value + (+value > 30 ? 1900 : 2000);
+    };
+
+    it('should get the current parser', function() {
+      expect(dateParser.getParser('yy')).toBeTruthy();
+    });
+
+    it('should override the parser', function() {
+      dateParser.overrideParser('yy', twoDigitYearParser);
+      expect(dateParser.parse('68', 'yy').getFullYear()).toEqual(1968);
+      expect(dateParser.parse('67', 'yy').getFullYear()).toEqual(1967);
+      expect(dateParser.parse('31', 'yy').getFullYear()).toEqual(1931);
+      expect(dateParser.parse('30', 'yy').getFullYear()).toEqual(2030);
+    });
+
+    it('should clear cached parsers', function() {
+      expect(dateParser.parse('68', 'yy').getFullYear()).toEqual(2068);
+      dateParser.overrideParser('yy', twoDigitYearParser);
+      expect(dateParser.parse('68', 'yy').getFullYear()).toEqual(1968);
+    });
+  });
 });