fix(typeahead): if display value cannot be determined, use the model value

If the element's model is not found in the typeahead's options, use the
model as the element's value instead of an empty string.

Author: Ben Struthers

src/typeahead/test/typeahead.spec.js

@@ -274,6 +274,10 @@ describe('typeahead', function () {
       expect(elm.val()).toBe(jQuery('div').html(scope.states[0]).text().trim());
     });
 
+    it('should use the model value if the display value cannot be determined', function () {
+      var elm = compileDirective('markup-objectValue', {}, function(scope) { scope.selectedIcon = 'Ge' });
+      expect(elm.val()).toBe('Ge'); // display value will be undefined, use model value for display
+    });
   });
 
   describe('bsOptions', function () {

src/typeahead/typeahead.js

@@ -146,7 +146,7 @@ angular.module('mgcrea.ngStrap.typeahead', ['mgcrea.ngStrap.tooltip', 'mgcrea.ng
         $typeahead.show = function() {
           show();
           // use timeout to hookup the events to prevent
-          // event bubbling from being processed imediately.
+          // event bubbling from being processed immediately.
           $timeout(function() {
             $typeahead.$element && $typeahead.$element.on('mousedown', $typeahead.$onMouseDown);
             if(options.keyboard) {
@@ -255,7 +255,16 @@ angular.module('mgcrea.ngStrap.typeahead', ['mgcrea.ngStrap.tooltip', 'mgcrea.ng
         controller.$formatters.push(function(modelValue) {
           // console.warn('$formatter("%s"): modelValue=%o (%o)', element.attr('ng-model'), modelValue, typeof modelValue);
           var displayValue = parsedOptions.displayValue(modelValue);
-          return displayValue === undefined ? '' : displayValue;
+
+          // If we can determine the displayValue, use that
+          if (displayValue) return displayValue;
+
+          // If there's no display value, attempt to use the modelValue.
+          // If the model is an object not much we can do
+          if (modelValue && typeof modelValue !== 'object') {
+            return modelValue;
+          }
+          return '';
         });
 
         // Model rendering in view