Tabs add prop beforeRemove, close #4379

src/components/tabs/tabs.vue

@@ -91,7 +91,8 @@
             closable: {
                 type: Boolean,
                 default: false
-            }
+            },
+            beforeRemove: Function,
         },
         data () {
             return {
@@ -247,6 +248,21 @@
                 this.handleChange(index);
             },
             handleRemove (index) {
+                if (!this.beforeRemove) {
+                    return this.handleRemoveTab(index);
+                }
+
+                const before = this.beforeRemove(index);
+
+                if (before && before.then) {
+                    before.then(() => {
+                        this.handleRemoveTab(index);
+                    });
+                } else {
+                    this.handleRemoveTab(index);
+                }
+            },
+            handleRemoveTab (index) {
                 const tabs = this.getTabs();
                 const tab = tabs[index];
                 tab.$destroy();