使用avalon实现SKU组合查询功能

SKU（stock keeping unit库存量单位）组合查询是网上商场一个非常常用的功能。具体来说，一件商品会有许多型号，许多颜色，许多产地，许多码寸，而满足用户选中的这些条件的具体商品可能有库存，也可能没有。我们把型号，颜色，产地，码寸什么的都分成一栏，每一栏的选项都有三种形态，可选，不可选，已选中。选中某一栏的一个选项的话，会影响到另外一些栏的项目的选中状态。如下图：

网上也有文章介绍它们的实现，涉及大量复杂的算法，HTML都是用JS动态生成的，非常不直观。并且那个东西这么简单，还要用那么复杂的算法啊，脑子被狗吃了。

• sku组合查询算法探索
• 淘宝SKU组合查询算法实现

在avalon中，由于VM对象是一个状态机，对这种联动功能有着天然的优势。我们只要把数据列出来，剩下的事就交给avalon好了。

下面是模板，它是由GITHUB的一个例子改过来的。一共五栏，换言之，VM有五个数组。然后里面每顶通过ms-class处理它们的状态。选择是通过点击事件实现，因此有ms-click。每个项目是否选中，通过涨是否等于某一个值判定，因此我搞了versionsChecked，colorsChecked，comboChecked等变量。

 <div ms-controller="sku" id="sku">
            <div>
                版本：
                <span ms-each-el="versions">
                    <span class="cell" ms-click="select(el, 'versions')"  ms-class-disabled='el.disabled' ms-class-checked='versionsChecked == el.value'>{{el.text}}</span>
                </span>
            </div>
            <div>
                机身颜色：
                <span ms-each-el="colors">
                    <span class="cell" ms-click="select(el, 'colors')" ms-class-disabled='el.disabled' ms-class-checked='colorsChecked == el.value'>{{el.text}}</span>
                </span>
            </div>
            <div>
                手机套餐：
                <span ms-each-el="combo">
                    <span class="cell"  ms-click="select(el, 'combo')" ms-class-disabled='el.disabled'  ms-class-checked='comboChecked == el.value'>{{el.text}}</span>
                </span>
            </div>
            <div>
                机身内存：
                <span ms-each-el="memory">
                    <span class="cell" ms-click="select(el, 'memory')" ms-class-disabled='el.disabled' ms-class-checked='memoryChecked == el.value'>{{el.text}}</span>
                </span>
            </div>
        </div>

sku最麻烦之处在于，点击了某一栏的项目会影响到其他栏的项目，这种逻辑我抽象成一个command命令，以columnName:item1,item2...;columnName2:item3,item4...;保存。

具体如下：

            var model = avalon.define("sku", function(vm) {
            vm.select = function(el, name) {
                    if (el.disabled)
                        return
                    var command = el.command
                    model[name + "Checked"] = el.value
                    command.split(";").forEach(function(str) {
                        var arr = str.split(":")
                        var check = arr[1]
                        var array = model[arr[0]] || []
                        array.forEach(function(elem) {
                            elem.disabled = !!(check && check.indexOf(elem.value) !== -1)
                        })
                    })
                }
                vm.versions = [
                    {value: 'cn', "text": "中国大陆", disabled: false,  command: "colors:lightgreen;"},
                    {value: "hk", text: "港澳台", checked: false,  command: "colors:lightyellow,black,blue,gray,yellow,white"},
                    {value: "eu", text: "欧洲", checked: false,  command: "colors:lightyellow,blue,gray,yellow,red,lightgreen"}
                ]
                vm.versionsChecked = ""

                vm.colors = [
                    {value: 'lightyellow', "text": "浅黄色", disabled: false, command: "versions:hk,eu"},
                    {value: "black", text: "黑色", disabled: false, command: "versions:hk"},
                    {value: "blue", text: "蓝色", disabled: false, command: "versions:hk,eu"},
                    {value: "gray", text: "浅灰色", disabled: false, command: "versions:hk,eu"},
                    {value: "yellow", text: "黄色", disabled: false, command: "versions:hk,eu"},
                    {value: "white", text: "白色", disabled: false, command: "versions:hk"},
                    {value: "lightgreen", text: "浅绿色", disabled: false, command: "versions:cn,eu;combo:set2,set3"},
                    {value: "red", text: "红色", disabled: false, command: "versions:eu"}

                ]
                vm.colorsChecked = ""

                vm.combo = [
                    {value: 'standard', "text": "官方标配", disabled: false,command: ""},
                    {value: "set2", text: "套餐二", disabled: false,command: "colors:lightgreen"},
                    {value: "set3", text: "套餐三", disabled: false,command: ""}
                ]
                vm.comboChecked = ""

                vm.memory = [{value: "32g", text: "32G", disabled: false,command: ""}]
                vm.memoryChecked = "32g"
            })

再加一点CSS装饰一下就搞定。

            #sku .cell{
                display:inline-block;
                padding:2px 5px;
                border:2px solid #ccc;
                color:#000;
                cursor:pointer;
                height: 18px;
                line-height: 18px;
            }
            #sku .cell.checked{
                border-color:red!important;
                color:red!important;
            }
            #sku .cell.disabled{
                border:2px dashed #d6d6d6;
                color:#cdcdcd;
                cursor:not-allowed;
            }
            #sku div{
                margin-top:10px;
            }

大家可以到我的GITHUB，下载回来运行