From 97476fec761517cae2791da357db936579f6cd50 Mon Sep 17 00:00:00 2001
From: neverland <chenjiahan@buaa.edu.cn>
Date: Tue, 11 Dec 2018 19:17:53 +0800
Subject: [PATCH] [improvement] Area: optimize performance (#1055)

---
 packages/area/index.less |  3 +--
 packages/area/index.ts   | 18 +++++++++---------
 packages/area/index.wxml |  3 ++-
 packages/wxs/array.wxs   |  4 ++--
 4 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/packages/area/index.less b/packages/area/index.less
index 72b95115..b82bf76d 100644
--- a/packages/area/index.less
+++ b/packages/area/index.less
@@ -57,11 +57,10 @@
 
     &__item {
       padding: 0 5px;
-      color: @gray-dark;
+      color: @text-color;
 
       &--selected {
         font-weight: 500;
-        color: @text-color;
       }
 
       &--disabled {
diff --git a/packages/area/index.ts b/packages/area/index.ts
index c3e0727e..c4f28f73 100644
--- a/packages/area/index.ts
+++ b/packages/area/index.ts
@@ -33,13 +33,6 @@ VantComponent({
     columns: []
   },
 
-  computed: {
-    displayColumns() {
-      const { columns = [], columnsNum } = this.data;
-      return columns.slice(0, +columnsNum);
-    }
-  },
-
   watch: {
     value(value) {
       this.code = value;
@@ -68,7 +61,8 @@ VantComponent({
 
     onChange(event: Weapp.Event) {
       const { value } = event.detail;
-      const { pickerValue, displayColumns } = this.data;
+      const { pickerValue } = this.data;
+      const displayColumns = this.getDisplayColumns();
       const index = pickerValue.findIndex(
         (item, index) => item !== value[index]
       );
@@ -159,7 +153,8 @@ VantComponent({
     },
 
     getValues() {
-      const { displayColumns = [], pickerValue = [] } = this.data;
+      const { pickerValue = [] } = this.data;
+      const displayColumns = this.getDisplayColumns();
       return displayColumns
         .map((option, index) => option[pickerValue[index]])
         .filter(value => !!value);
@@ -201,6 +196,11 @@ VantComponent({
     reset() {
       this.code = '';
       this.setValues();
+    },
+
+    getDisplayColumns() {
+      const { columns = [], columnsNum } = this.data;
+      return columns.slice(0, +columnsNum);
     }
   }
 });
diff --git a/packages/area/index.wxml b/packages/area/index.wxml
index cf401704..bec4249b 100644
--- a/packages/area/index.wxml
+++ b/packages/area/index.wxml
@@ -17,7 +17,8 @@
     class="van-picker__columns"
   >
     <picker-view-column
-      wx:for="{{ displayColumns }}"
+      wx:if="{{ rowIndex < columnsNum }}"
+      wx:for="{{ columns }}"
       wx:for-item="row"
       wx:for-index="rowIndex"
       wx:key="rowIndex"
diff --git a/packages/wxs/array.wxs b/packages/wxs/array.wxs
index 28753fa5..610089cd 100644
--- a/packages/wxs/array.wxs
+++ b/packages/wxs/array.wxs
@@ -1,5 +1,5 @@
-function isArray(obj) {
-  return obj && obj.constructor === 'Array';
+function isArray(array) {
+  return array && array.constructor === 'Array';
 }
 
 module.exports.isArray = isArray;