使用lodash从平面列表创建树

时间:2015-08-21 06:52:09

标签: javascript tree lodash

我正在尝试使用下面的json对象数组创建一个类别树。 我希望将一个类别设置为另一个类别的子级,如果其父级等于另一个类别的id,我希望这些帖子也是该类别的子级而不是为帖子设置单独的字段,我将添加一个标志字段,如果它是一个类别,则为isParent

看起来它的工作正常,但正如您所看到的,如果某个类别同时具有类别和帖子作为子项,则它仅显示类别。另一个问题是,如果帖子的数组上有空值,它仍会将它们作为子项推送。

我的代码中有哪些错误,或者是否有更简单或更好的解决方案?



var tree = unflatten(getData());
var pre = document.createElement('pre');
console.log(tree);
pre.innerText = JSON.stringify(tree, null, 4);

document.body.appendChild(pre);

function unflatten(array, parent, tree) {
  tree = typeof tree !== 'undefined' ? tree : [];
  parent = typeof parent !== 'undefined' ? parent : {
    id: 0
  };
  _.map(array, function(arr) {
    _.set(arr, 'isParent', true);
  });
  var children = _.filter(array, function(child) {
    return child.parent == parent.id;
  });

  if (!_.isEmpty(children)) {
    if (parent.id == 0) {
      tree = children;
    } else {
      parent['children'] = children;
    }
    _.each(children, function(child) {
      var posts = _.map(child.posts, function(post) {
        return _.set(post, 'isParent', false);
      });
      child['children'] = posts;
      delete child.posts;
      unflatten(array, child);
    });
  }

  return tree;

}

function getData() {
  return [{
    "id": "c1",
    "parent": "",
    "name": "foo",
    "posts": [{
      "id": "p1"
    }]
  }, {
    "id": "c2",
    "parent": "1",
    "name": "bar",
    "posts": [{
      "id": "p2"
    }]
  }, {
    "id": "c3",
    "parent": "",
    "name": "bazz",
    "posts": [
      null
    ]
  }, {
    "id": "c4",
    "parent": "3",
    "name": "sna",
    "posts": [{
      "id": "p3"
    }]
  }, {
    "id": "c5",
    "parent": "3",
    "name": "ney",
    "posts": [{
      "id": "p4"
    }]
  }, {
    "id": "c6",
    "parent": "5",
    "name": "tol",
    "posts": [{
      "id": "p5"
    }, {
      "id": "p6"
    }]
  }, {
    "id": "c7",
    "parent": "5",
    "name": "zap",
    "posts": [{
      "id": "p7"
    }, {
      "id": "p8"
    }, {
      "id": "p9"
    }]
  }, {
    "id": "c8",
    "parent": "",
    "name": "quz",
    "posts": [
      null
    ]
  }, {
    "id": "c9",
    "parent": "8",
    "name": "meh",
    "posts": [{
      "id": "p10"
    }, {
      "id": "p11"
    }]
  }, {
    "id": "c10",
    "parent": "8",
    "name": "ror",
    "posts": [{
      "id": "p12"
    }, {
      "id": "p13"
    }]
  }, {
    "id": "c11",
    "parent": "",
    "name": "gig",
    "posts": [{
      "id": "p14"
    }]
  }, {
    "id": "c12",
    "name": "xylo",
    "parent": "",
    "posts": [{
      "id": "p15"
    }]
  }, {
    "id": "c13",
    "parent": "",
    "name": "grr",
    "posts": [{
      "id": "p16"
    }, {
      "id": "p17"
    }, {
      "id": "p14"
    }, {
      "id": "p18"
    }, {
      "id": "p19"
    }, {
      "id": "p20"
    }]
  }]
}

<script src="//cdn.jsdelivr.net/lodash/3.10.1/lodash.min.js"></script>
&#13;
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预期输出

所以预期的输出更像是:

[
   {
       id: 'c1',
       isParent: true,
       children: [
          {
             id: 'c2',
             isParent: true,
             children: []
          },
          {
             id: 'p1'
             isParent: false
          }
       ]
   }
]

等等..

1 个答案:

答案 0 :(得分:3)

我已经做了一个小小的fidde,我认为这就是你想要的。

http://jsfiddle.net/tx3uwhke/

var tree = buildTree(getData());
var pre = document.getElementById('a');
var jsonString = JSON.stringify(tree, null, 4);
console.log(jsonString);
pre.innerHTML = jsonString;

document.body.appendChild(pre);

function buildTree(data, parent){
    var result = [];
    parent = typeof parent !== 'undefined' ? parent : {id:""};
    children = _.filter(data, function(value){
        return value.parent === parent.id;
    });
    if(!_.isEmpty(children)){
        _.each(children, function(child){
            if (child != null){
                result.push(child);
                if(!_.isEmpty(child.posts)){
                    var posts = _.filter(child.posts, function(post){
                        return post !== null && typeof post !== 'undefined';
                    });
                    if(!_.isEmpty(posts)){
                        _.forEach(posts, function(post){
                            post.isParent = false;
                        });
                    }
                    result = _.union(result, posts);
                    delete child.posts;
                }
                ownChildren = buildTree(data, child);
                if(!_.isEmpty(ownChildren)){
                    child.isParent = true;
                    child.children = ownChildren;
                }else{
                    child.isParent = false;
                }
            }
        });
    }
    return result;
}

编辑:制作一个新的小提琴,以包含isParent部分here