Datetime NPE fixes and save timezone per default for time control (#84)

* DateTime control:
  * fix NPE issues
  * only reset the value when action buttons are present
* remove unnecessary set in Date renderer
* add vueCompilerOptions
* Adapt default time save format of the time control to include the timezone to fulfill RFC3339 time

Author: kchobantonov

Diff for: example/src/examples/control/data.json

@@ -4,7 +4,7 @@
   "number": 50.5,
   "integer": 50,
   "date": "2020-06-25",
-  "time": "23:08:00",
+  "time": "23:08:00Z",
   "dateTime": "2020-06-25T23:08:42+02:00",
   "enum": "Two"
 }

Diff for: example/tsconfig.json

@@ -36,5 +36,8 @@
   ],
   "exclude": [
     "node_modules"
-  ]
+  ],
+  "vueCompilerOptions": {
+    "target": 2.7
+  }
 }

Diff for: vue2-vuetify/src/controls/DateControlRenderer.vue

@@ -293,9 +293,6 @@ const controlRenderer = defineComponent({
     onYear(year: number): void {
       if (this.pickerType === 'year') {
         this.pickerValue = `${year}`;
-        if (this.$refs?.picker) {
-          (this.$refs.picker as any).internalActivePicker = 'YEAR';
-        }
         if (!this.showActions) {
           this.okHandler();
         }

Diff for: vue2-vuetify/src/controls/DateTimeControlRenderer.vue

@@ -414,7 +414,7 @@ const controlRenderer = defineComponent({
         return date ? date.format('YYYY-MM-DD') : undefined;
       },
       set(val: string) {
-        this.onPickerChange(val, (this.$refs.timePicker as any).genValue());
+        this.onPickerChange(val, this.timePickerValue);
       },
     },
     timePickerValue: {
@@ -430,7 +430,7 @@ const controlRenderer = defineComponent({
           : undefined;
       },
       set(val: string) {
-        this.onPickerChange((this.$refs.datePicker as any).inputDate, val);
+        this.onPickerChange(this.datePickerValue, val);
       },
     },
     pickerValue: {
@@ -445,7 +445,9 @@ const controlRenderer = defineComponent({
       },
       set(val: string) {
         const dateTime = parseDateTime(val, 'YYYY-MM-DDTHH:mm:ss.SSSZ');
-        this.onChange(dateTime!.format(this.dateTimeSaveFormat));
+        if (dateTime && this.showActions) {
+          this.onChange(dateTime.format(this.dateTimeSaveFormat));
+        }
       },
     },
     clearLabel(): string {
@@ -484,7 +486,7 @@ const controlRenderer = defineComponent({
         this.onChange(newdata);
       }
     },
-    onPickerChange(dateValue: string, timeValue: string): void {
+    onPickerChange(dateValue?: string, timeValue?: string): void {
       const date = parseDateTime(dateValue, 'YYYY-MM-DD');
       const time = parseDateTime(
         timeValue ?? (this.useSeconds ? '00:00:00' : '00:00'),

Diff for: vue2-vuetify/src/controls/TimeControlRenderer.vue

@@ -174,7 +174,7 @@ const controlRenderer = defineComponent({
     timeSaveFormat(): string {
       return typeof this.appliedOptions.timeSaveFormat == 'string'
         ? this.appliedOptions.timeSaveFormat
-        : 'HH:mm:ss';
+        : 'HH:mm:ssZ';
     },
     formats(): string[] {
       return [

Diff for: vue2-vuetify/tsconfig.json

@@ -30,5 +30,8 @@
   "exclude": [
     "node_modules",
     "lib"
-  ]
+  ],
+  "vueCompilerOptions": {
+    "target": 2.7
+  }
 }