调整Tabs和Drawer的beforeRemove/beforeClose处理

examples/routers/drawer.vue

@@ -216,10 +216,10 @@
                         title: '关闭确认',
                         content: '您确认要关闭抽屉吗？',
                         onOk: () => {
-                            resolve();
+                            resolve(true);
                         },
                         onCancel: () => {
-                            reject();
+                            resolve(false);
                         }
                     });
                 });

src/components/drawer/drawer.vue

@@ -182,12 +182,17 @@
                 }
 
                 const before = this.beforeClose();
+                if (!before) { // sync function returned falsy, don't close
+                    return;
+                }
 
-                if (before && before.then) {
-                    before.then(() => {
-                        this.handleClose();
+                if (before.then) {  // promise
+                    before.then((result) => {
+                        if (result) {   // promise resolved truthy
+                            this.handleClose();
+                        }
                     });
-                } else {
+                } else { // sync returned truthy
                     this.handleClose();
                 }
             },
@@ -309,4 +314,4 @@
             }
         }
     };
-</script>
+</script>

src/components/tabs/tabs.vue

@@ -377,12 +377,17 @@
                 }
 
                 const before = this.beforeRemove(index);
+                if (!before) { // returned falsy, don't close tab
+                    return;
+                }
 
-                if (before && before.then) {
-                    before.then(() => {
-                        this.handleRemoveTab(index);
+                if (before.then) {  // promise
+                    before.then((result) => {
+                        if (result) {   // promise resolved truthy
+                            this.handleRemoveTab(index);
+                        }
                     });
-                } else {
+                } else { // sync returned truthy
                     this.handleRemoveTab(index);
                 }
             },