feat(select): Add notNull and nullDisplay properties (#111)

Author: OskarPersson

README.md

@@ -260,6 +260,12 @@ _Example radio field_
 ##### optionsAttr (string, optional)
 >`optionsAttr` is what is used as the attribute ngOptions will be applied to. Defaults to `ng-options`
 
+##### notNull (boolean, optional)
+>`notNull` whether to add an empty null option
+
+##### nullDisplay (string, optional)
+>`nullDisplay` Null option label
+
 ##### ngOptions (string, optional)
 >If provided, this is used instead of the default `ng-options` giving you full control (and rendering the other options uncessisary.
 

src/types/select.js

@@ -1,7 +1,9 @@
 export default  ngModule => {
   ngModule.config(addSelectType);
 
-  const template = `<select class="form-control" ng-model="model[options.key]"></select>`;
+  const template = `<select class="form-control" ng-model="model[options.key]">
+      <option ng-hide="to.notNull" value="">{{to.nullDisplay}}</option>
+  </select>`;
 
   function addSelectType(formlyConfigProvider) {
     formlyConfigProvider.setType({
@@ -25,7 +27,9 @@ export default  ngModule => {
           optionsAttr: check.string.optional,
           labelProp: check.string.optional,
           valueProp: check.string.optional,
-          groupProp: check.string.optional
+          groupProp: check.string.optional,
+          notNull: check.boolean.optional,
+          nullDisplay: check.string.optional
         }
       })
     });