accompanying course: add client-side validation if no origin

src/Bundle/ChillPersonBundle/Resources/public/vuejs/AccompanyingCourse/components/OriginDemand.vue

@@ -19,15 +19,18 @@
             :options="options"
             @select="updateOrigin">
          </VueMultiselect>
-
       </div>
+
+      <div v-if="!isOriginValid" class="alert alert-warning to-confirm">
+        {{ $t('origin.not_valid') }}
+     </div>
    </div>
 </template>
 
 <script>
 import VueMultiselect from 'vue-multiselect';
 import { getListOrigins } from '../api';
-import { mapState } from 'vuex';
+import { mapState, mapGetters } from 'vuex';
 
 export default {
    name: 'OriginDemand',
@@ -41,6 +44,9 @@ export default {
       ...mapState({
          value: state => state.accompanyingCourse.origin,
       }),
+      ...mapGetters([
+         'isOriginValid'
+      ])
    },
    mounted() {
       this.getOptions();