javascript - 从 JSON 对象数组构建树

Question

给定以下 JSON 数组:

    [{"ID":12,"NAME":"ktc","PARENTID":0},
     {"ID":11,"NAME":"root","PARENTID":0}, 
     {"ID":1,"NAME":"rwhitney","PARENTID":0},
     {"ID":21,"NAME":"shared folder","PARENTID":0}, 
     {"ID":2,"NAME":".config","PARENTID":1}, 
     {"ID":5,"NAME":"wallpapers","PARENTID":1}, 
     {"ID":3,"NAME":"geany","PARENTID":2}, 
     {"ID":4,"NAME":"colorschemes","PARENTID":3}, 
     {"ID":13,"NAME":"efast","PARENTID":12}, 
     {"ID":15,"NAME":"includes","PARENTID":13}, 
     {"ID":14,"NAME":"views","PARENTID":13}, 
     {"ID":17,"NAME":"css","PARENTID":15}, 
     {"ID":16,"NAME":"js","PARENTID":15}]

我需要构建一个菜单树，其中的子文件夹嵌套在父文件夹下。

这是一些服务器端代码:

    socket.on('get-folders', function(data){
        var folders = [];
        getSession(session.key, function(currSession){
            db.rows('getFolders', currSession, [currSession.user], function(err, rows){
                if (err) {
                    socket.emit('err', 'Error is: ' + err );
                } else if(rows[0]){
                    //~ folders.push(JSON.stringify(rows));
                    socket.emit('get-folders', JSON.stringify(rows));
                    //~ n_Folders(rows, currSession, socket, folders, 0);
                }
            });
        });
    });

和客户端:

    function rtnSocket(cmd, data, cb){
        socket.emit(cmd, data);
        socket.on(cmd, cb);
    }

    rtnSocket('get-folders', folderid, function(data){
        console.log(data);
    });

有人可以帮助指导我正确的方向吗？

Answer 1

您可以从平面数据结构中收集所有 Node ，使用 ID 和 PARENTID 作为哈希表中的键，并获取根数组作为结果。

var data = [{ ID: 12, NAME: "ktc", PARENTID: 0 }, { ID: 11, NAME: "root", PARENTID: 0 }, { ID: 1, NAME: "rwhitney", PARENTID: 0 }, { ID: 21, NAME: "shared folder", PARENTID: 0 }, { ID: 13, NAME: "efast", PARENTID: 12 }, { ID: 2, NAME: ".config", PARENTID: 1 }, { ID: 5, NAME: "wallpapers", PARENTID: 1 }, { ID: 15, NAME: "includes", PARENTID: 13 }, { ID: 14, NAME: "views", PARENTID: 13 }, { ID: 3, NAME: "geany", PARENTID: 2 }, { ID: 17, NAME: "css", PARENTID: 15 }, { ID: 16, NAME: "js", PARENTID: 15 }, { ID: 4, NAME: "colorschemes", PARENTID: 3 }],
    tree = function (data, root) {
        var t = {};
        data.forEach(o => {
            Object.assign(t[o.ID] = t[o.ID] || {}, o);
            t[o.PARENTID] = t[o.PARENTID] || {};
            t[o.PARENTID].children = t[o.PARENTID].children || [];
            t[o.PARENTID].children.push(t[o.ID]);
        });
        return t[root].children;
    }(data, 0);

console.log(tree);

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