layui框架实战案例(17)：流加载文档layui.flow组件的前后端解决方案

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前言

layui.flow，模块包含信息流加载和图片懒加载两大核心支持，无论是对服务端、还是前端体验，都有非常大的性能帮助。

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一、模块flow

模块加载名称：flow

layui.use('flow', function(){
  var flow = layui.flow;
  //信息流
  flow.load(options);
  
  //图片懒加载
  flow.lazyimg(options);
});

二、使用步骤

信息流加载的解决方案

HTML容器构造

    <meta name="viewport" content="width=device-width, initial-scale=1,maximum-scale=1,user-scalable=no">
    <title>信息流title>
    
    <script src="js/layui/layui.js" charset="utf-8">script>
    <link rel="stylesheet" href="js/layui/css/layui.css">

<ul class="flow-default" id="lock_data">ul>

2.API数据示例

{
    "err": "",
    "res": "",
    "data": [
        {
            "depart_id": "12",
            "province": "山东省",
            "city": "济南市",
            "area": "历下区",
            "user_name": "张思",
            "user_url": "upload/photo/1065_cf9f8858d59740b387b6f78581522201.JPG"
        }
    ],
    "code": 0,
    "count": 112
}

3.PHP后端代码

根据前端代码需求，开发对应的API接口。其中page是通过get方式获取的，在实际生产环境中，注意过滤参数，防止SQL注入即可

  public function getMarkers()
    {
        global $db, $res;
        dbc();
        @$p = $_GET['page'] == "" ? 1 : $_GET['page'];//获取用户选择的页码
        @$pagesize = $_GET['limit'] == "" ? 15 : $_GET['limit'];//获取用户选择的每页显示多少条数据
        @$limit = ($p - 1) * $pagesize;//偏移量

        //获取数据;
        $sql = "select a.depart_id,a.depart_name,a.province,a.city,a.area,a.depart_address,a.poi_lng,a.poi_lat,b.depart_id,b.user_id,b.user_name,b.user_url FROM " . $db->table('depart') . " AS a, " . $db->table('user') . " AS b WHERE a.depart_id = b.depart_id";
        $sql .= " ORDER BY a.depart_id LIMIT " . $limit . "," . $pagesize;
        $row = $db->queryall($sql);

        //获取总记录;
        $sql_c = "select a.depart_id,b.depart_id FROM " . $db->table('depart') . " AS a, " . $db->table('user') . " AS b WHERE a.depart_id = b.depart_id";
        $sql_c .= " ORDER BY user_depart";
        $row_c = $db->queryall($sql_c);
        $res['code'] = 0;
        $res['count'] = count($row_c);
        $res["data"] = $row;
        die(json_encode_lockdata($res));
    }

4.核心代码

 layui.use('flow', function () {
        var $ = layui.jquery; 
        var flow = layui.flow;
        flow.load({
            elem: '#lock_data' //指定列表容器
            , end: '数据加载完毕' //没有数据的提示文字
            , isAuto: false
            , done: function (page, next) { //到达临界点（默认滚动触发），触发下一页
                console.log(page)
                var lis = [];
                $.getJSON('http://test.com/flow/api/api.php?act=getMarkers&token=3cab7ce4142608c0f40c785b5ab5ca24&page=' + page, function (res) {
                    layui.each(res.data, function (index, item) {
                        lis.push('
' + item.user_name + '
');
                    });

                    //pages为Ajax返回的总页数，只有当前页小于总页数的情况下，才会继续出现加载更多
                    next(lis.join(''), page < res.count / 15);
                });

            }
        });
    });

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总结

在参考官方案例时，需要注意 next(lis.join(''), page < res.count / 15);pages为Ajax返回的总页数，只有当前页小于总页数的情况下，才会继续出现加载更多，按照实际传参为准。