OnTheFly modal: adapt footer button for show/edit cases (bug minor)

[BUG] to reproduce:
* clic first on show item button
* in modal clic edit button
* close modal
* clic again on show item button

src/Bundle/ChillMainBundle/Resources/public/vuejs/_components/OnTheFly.vue

@@ -39,7 +39,12 @@
          </template>
             
          <template v-slot:footer>
-            <button class="sc-button bt-save"> <!-- @click.prevent="$emit('..', ..)" -->
+            <button v-if="action === 'show'"
+               @click="changeActionTo('edit')"
+               class="sc-button bt-update"> <!-- @click.prevent="$emit('..', ..)" -->
+            </button>
+            <button v-else
+               class="sc-button bt-save"> <!-- @click.prevent="$emit('..', ..)" -->
                {{ $t('action.save')}}
             </button>
          </template>
@@ -69,10 +74,14 @@ export default {
          modal: {
             showModal: false,
             modalDialogClass: "modal-dialog-scrollable modal-xl"
-         }
+         },
+         action: this.action
       }
    },
    computed: {
+      action() {
+         return this.$data.action;
+      },
       classAction() {
          switch (this.action) {
             case 'show':
@@ -102,7 +111,7 @@ export default {
             case 'create':
                return 'onthefly.create.title';
          }
-      },
+      }
    },
    methods: {
       openModal() {
@@ -110,6 +119,10 @@ export default {
          this.$nextTick(function() {
             //this.$refs.search.focus();
          })
+      },
+      changeActionTo(action) {
+         // [BUG] clic first on show item button; in modal clic edit button; close modal; clic again on show item button
+         this.$data.action = action; 
       }
    }
 }