微信小程序商城项目之商品属性分类（4）

续上一篇的文章：微信小程序之购物数量加减 —— 微信小程序实战商城系列（3）
所提及的购物数量的加减，现在说说商品属性值联动选择。

为了让同学们有个直观的了解，到电商网截了一个图片，就是红圈所示的部分

现在就为大家介绍这个小组件，在小程序中，该如何去写
下图为本项目的图：

wxml：

<view class="title">商品属性值联动选择</view>
<!--options-->
<view class="commodity_attr_list">
 <!--每组属性-->
 <view class="attr_box" wx:for="{{attrValueList}}" wx:for-item="attrValueObj" wx:for-index="attrIndex">
 <!--属性名-->
 <view class="attr_name">{{attrValueObj.attrKey}}</view>
 <!--属性值-->
 <view class="attr_value_box">
 <!--每个属性值-->
 <view class="attr_value {{attrIndex==firstIndex || attrValueObj.attrValueStatus[valueIndex]?(value==attrValueObj.selectedValue?'attr_value_active':''):'attr_value_disabled'}}" bindtap="selectAttrValue" data-status="{{attrValueObj.attrValueStatus[valueIndex]}}"
 data-value="{{value}}" data-key="{{attrValueObj.attrKey}}" data-index="{{attrIndex}}" data-selectedvalue="{{attrValueObj.selectedValue}}" wx:for="{{attrValueObj.attrValues}}" wx:for-item="value" wx:for-index="valueIndex">{{value}}</view>
 </view>
 </view>
</view>
<!--button-->
<view class="weui-btn-area">
 <button class="weui-btn" type="primary" bindtap="submit">确定</button>
</view>

wxss：

.title {
 padding: 10rpx 20rpx;
 margin: 10rpx 0;
 border-left: 4rpx solid #ccc;
} 

/*全部属性的主盒子*/
.commodity_attr_list {
 background: #fff;
 padding: 0 20rpx;
 font-size: 26rpx;
 overflow: hidden;
 width: 100%;
}
/*每组属性的主盒子*/
.attr_box {
 width: 100%;
 overflow: hidden;
 border-bottom: 1rpx solid #ececec;
}
/*属性名*/
.attr_name {
 width: 20%;
 float: left;
 padding: 15rpx 0;
}
/*属性值*/
.attr_value_box {
 width: 80%;
 float: left;
 padding: 15rpx 0;
 overflow: hidden;
}
/*每个属性值*/
.attr_value {
 float: left;
 padding: 0 10rpx;
 margin: 0 10rpx;
 border: 1rpx solid #ececec;
}
/*每个属性选中的当前样式*/
.attr_value_active {
 background: #FFCC00;
 border-radius: 10rpx;
 color: #fff;
 padding: 0 10rpx;
}
/*禁用属性*/
.attr_value_disabled {
 color: #ccc;
} 

/*button*/
.btn-area {
 margin: 1.17647059em 15px 0.3em;
} 

.btn {
 margin-top: 15px;
 background-color:#FFCC00;
 color: #fff;
}
.btn:first-child {
 margin-top: 0;
}

js：

数据部分，一般情况都是访问接口获取数据的，这里并没有使用网络访问，为了简化demo，直接把一组数据放在data对象中。

Page({
 data: {
 firstIndex: -1,
 //准备数据
 //数据结构：以一组一组来进行设定
 commodityAttr: [
 {
 priceId: 1,
 price: 35.0,
 "stock": 8,
 "attrValueList": [
 {
 "attrKey": "型号",
 "attrValue": "2"
 },
 {
 "attrKey": "颜色",
 "attrValue": "白色"
 },
 {
 "attrKey": "大小",
 "attrValue": "小"
 },
 {
 "attrKey": "尺寸",
 "attrValue": "S"
 }
 ]
 },
 {
 priceId: 2,
 price: 35.1,
 "stock": 9,
 "attrValueList": [
 {
 "attrKey": "型号",
 "attrValue": "1"
 },
 {
 "attrKey": "颜色",
 "attrValue": "黑色"
 },
 {
 "attrKey": "大小",
 "attrValue": "小"
 },
 {
 "attrKey": "尺寸",
 "attrValue": "M"
 }
 ]
 },
 {
 priceId: 3,
 price: 35.2,
 "stock": 10,
 "attrValueList": [
 {
 "attrKey": "型号",
 "attrValue": "1"
 },
 {
 "attrKey": "颜色",
 "attrValue": "绿色"
 },
 {
 "attrKey": "大小",
 "attrValue": "大"
 },
 {
 "attrKey": "尺寸",
 "attrValue": "L"
 }
 ]
 },
 {
 priceId: 4,
 price: 35.2,
 "stock": 10,
 "attrValueList": [
 {
 "attrKey": "型号",
 "attrValue": "1"
 },
 {
 "attrKey": "颜色",
 "attrValue": "绿色"
 },
 {
 "attrKey": "大小",
 "attrValue": "大"
 },
 {
 "attrKey": "尺寸",
 "attrValue": "L"
 }
 ]
 }
 ],
 attrValueList: []
 },
 onShow: function () {
 this.setData({
 includeGroup: this.data.commodityAttr
 });
 this.distachAttrValue(this.data.commodityAttr);
 // 只有一个属性组合的时候默认选中
 // console.log(this.data.attrValueList);
 if (this.data.commodityAttr.length == 1) {
 for (var i = 0; i < this.data.commodityAttr[0].attrValueList.length; i++) {
 this.data.attrValueList[i].selectedValue = this.data.commodityAttr[0].attrValueList[i].attrValue;
 }
 this.setData({
 attrValueList: this.data.attrValueList
 });
 }
 },
 /* 获取数据 */
 distachAttrValue: function (commodityAttr) {
 /**
 将后台返回的数据组合成类似
 {
 attrKey:'型号',
 attrValueList:['1','2','3']
 }
 */
 // 把数据对象的数据（视图使用），写到局部内
 var attrValueList = this.data.attrValueList;
 // 遍历获取的数据
 for (var i = 0; i < commodityAttr.length; i++) {
 for (var j = 0; j < commodityAttr[i].attrValueList.length; j++) {
 var attrIndex = this.getAttrIndex(commodityAttr[i].attrValueList[j].attrKey, attrValueList);
 // console.log('属性索引', attrIndex);
 // 如果还没有属性索引为-1，此时新增属性并设置属性值数组的第一个值；索引大于等于0，表示已存在的属性名的位置
 if (attrIndex >= 0) {
 // 如果属性值数组中没有该值，push新值；否则不处理
 if (!this.isValueExist(commodityAttr[i].attrValueList[j].attrValue, attrValueList[attrIndex].attrValues)) {
 attrValueList[attrIndex].attrValues.push(commodityAttr[i].attrValueList[j].attrValue);
 }
 } else {
 attrValueList.push({
 attrKey: commodityAttr[i].attrValueList[j].attrKey,
 attrValues: [commodityAttr[i].attrValueList[j].attrValue]
 });
 }
 }
 }
 // console.log('result', attrValueList)
 for (var i = 0; i < attrValueList.length; i++) {
 for (var j = 0; j < attrValueList[i].attrValues.length; j++) {
 if (attrValueList[i].attrValueStatus) {
 attrValueList[i].attrValueStatus[j] = true;
 } else {
 attrValueList[i].attrValueStatus = [];
 attrValueList[i].attrValueStatus[j] = true;
 }
 }
 }
 this.setData({
 attrValueList: attrValueList
 });
 },
 getAttrIndex: function (attrName, attrValueList) {
 // 判断数组中的attrKey是否有该属性值
 for (var i = 0; i < attrValueList.length; i++) {
 if (attrName == attrValueList[i].attrKey) {
 break;
 }
 }
 return i < attrValueList.length ? i : -1;
 },
 isValueExist: function (value, valueArr) {
 // 判断是否已有属性值
 for (var i = 0; i < valueArr.length; i++) {
 if (valueArr[i] == value) {
 break;
 }
 }
 return i < valueArr.length;
 },
 /* 选择属性值事件 */
 selectAttrValue: function (e) {
 /*
 点选属性值，联动判断其他属性值是否可选
 {
 attrKey:'型号',
 attrValueList:['1','2','3'],
 selectedValue:'1',
 attrValueStatus:[true,true,true]
 }
 console.log(e.currentTarget.dataset);
 */
 var attrValueList = this.data.attrValueList;
 var index = e.currentTarget.dataset.index;//属性索引
 var key = e.currentTarget.dataset.key;
 var value = e.currentTarget.dataset.value;
 if (e.currentTarget.dataset.status || index == this.data.firstIndex) {
 if (e.currentTarget.dataset.selectedvalue == e.currentTarget.dataset.value) {
 // 取消选中
 this.disSelectValue(attrValueList, index, key, value);
 } else {
 // 选中
 this.selectValue(attrValueList, index, key, value);
 } 

 }
 },
 /* 选中 */
 selectValue: function (attrValueList, index, key, value, unselectStatus) {
 // console.log('firstIndex', this.data.firstIndex);
 var includeGroup = [];
 if (index == this.data.firstIndex && !unselectStatus) { // 如果是第一个选中的属性值，则该属性所有值可选
 var commodityAttr = this.data.commodityAttr;
 // 其他选中的属性值全都置空
 // console.log('其他选中的属性值全都置空', index, this.data.firstIndex, !unselectStatus);
 for (var i = 0; i < attrValueList.length; i++) {
 for (var j = 0; j < attrValueList[i].attrValues.length; j++) {
 attrValueList[i].selectedValue = '';
 }
 }
 } else {
 var commodityAttr = this.data.includeGroup;
 } 

 // console.log('选中', commodityAttr, index, key, value);
 for (var i = 0; i < commodityAttr.length; i++) {
 for (var j = 0; j < commodityAttr[i].attrValueList.length; j++) {
 if (commodityAttr[i].attrValueList[j].attrKey == key && commodityAttr[i].attrValueList[j].attrValue == value) {
 includeGroup.push(commodityAttr[i]);
 }
 }
 }
 attrValueList[index].selectedValue = value; 

 // 判断属性是否可选
 for (var i = 0; i < attrValueList.length; i++) {
 for (var j = 0; j < attrValueList[i].attrValues.length; j++) {
 attrValueList[i].attrValueStatus[j] = false;
 }
 }
 for (var k = 0; k < attrValueList.length; k++) {
 for (var i = 0; i < includeGroup.length; i++) {
 for (var j = 0; j < includeGroup[i].attrValueList.length; j++) {
 if (attrValueList[k].attrKey == includeGroup[i].attrValueList[j].attrKey) {
 for (var m = 0; m < attrValueList[k].attrValues.length; m++) {
 if (attrValueList[k].attrValues[m] == includeGroup[i].attrValueList[j].attrValue) {
 attrValueList[k].attrValueStatus[m] = true;
 }
 }
 }
 }
 }
 }
 // console.log('结果', attrValueList);
 this.setData({
 attrValueList: attrValueList,
 includeGroup: includeGroup
 }); 

 var count = 0;
 for (var i = 0; i < attrValueList.length; i++) {
 for (var j = 0; j < attrValueList[i].attrValues.length; j++) {
 if (attrValueList[i].selectedValue) {
 count++;
 break;
 }
 }
 }
 if (count < 2) {// 第一次选中，同属性的值都可选
 this.setData({
 firstIndex: index
 });
 } else {
 this.setData({
 firstIndex: -1
 });
 }
 },
 /* 取消选中 */
 disSelectValue: function (attrValueList, index, key, value) {
 var commodityAttr = this.data.commodityAttr;
 attrValueList[index].selectedValue = ''; 

 // 判断属性是否可选
 for (var i = 0; i < attrValueList.length; i++) {
 for (var j = 0; j < attrValueList[i].attrValues.length; j++) {
 attrValueList[i].attrValueStatus[j] = true;
 }
 }
 this.setData({
 includeGroup: commodityAttr,
 attrValueList: attrValueList
 }); 

 for (var i = 0; i < attrValueList.length; i++) {
 if (attrValueList[i].selectedValue) {
 this.selectValue(attrValueList, i, attrValueList[i].attrKey, attrValueList[i].selectedValue, true);
 }
 }
 },
 /* 点击确定 */
 submit: function () {
 var value = [];
 for (var i = 0; i < this.data.attrValueList.length; i++) {
 if (!this.data.attrValueList[i].selectedValue) {
 break;
 }
 value.push(this.data.attrValueList[i].selectedValue);
 }
 if (i < this.data.attrValueList.length) {
 wx.showToast({
 title: '请完善属性',
 icon: 'loading',
 duration: 1000
 })
 } else {
 wx.showToast({
 title: '选择的属性：' + value.join('-'),
 icon: 'sucess',
 duration: 1000
 })
 }
 }
}) 

运行效果：

demo地址：微信小程序商城项目之商品属性值联动选择

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