如何基于点符号和“类型”属性将平面数组转换为树数组？

Question

我想在下面转换一个平面数组：

$array = [
   [
    "hierarchy" => "1",
    "title" => "Fruits",
    "type" => "category_label"
   ],
   [
    "hierarchy" => "1.1",
    "title" => "Citruses",
    "type" => "category_label"
   ],
   [
    "hierarchy" => "1.1.1",
    "title" => "Orange",
    "type" => "item"
   ],
   [
    "hierarchy" => "1.1",
    "title" => "Mango",
    "type" => "item"
   ],
   [
    "hierarchy" => "1.2",
    "title" => "Grape",
    "type" => "item"
   ]
];

从上面可以看出，它有两个分层的点符号字符串“1.1”，因此我使用“type”属性来区分它们。

我期待什么结果：

/*
1. Fruits
-  1.1. Citruses
--- 1.1.1. Orange
-- 1.1. Mango
-- 1.2. Grape
*/

//Desired result
[
    "hierarchy" => "1",
    "title" => "Fruits",
    "type" => "category_label",
    "children" => [
        [
            "hierarchy" => "1.1",
            "title" => "Citruses",
            "type" => "category_label"
            "children" => [
                [
                    "hierarchy" => "1.1.1",
                    "title" => "Orange",
                    "type" => "item"
                ]
            ]
        ],
        [
            "hierarchy" => "1.1",
            "title" => "Mango",
            "type" => "item"
        ],
        [
            "hierarchy" => "1.2",
            "title" => "Grape",
            "type" => "item"
        ]
    ]
];

使用How to build a tree from a concatenated string in PHP? 中描述的方法我无法达到我想要的结果。 我现在能做什么？

Answer 1

看看这个逻辑是否有帮助，我会在 1 天内尝试编辑答案并解释。

$tree_array = [];
foreach($array as $key => $value){
    if(count(explode('.',$value['hierarchy']) == 1){
        array_push($array_tree, $value)
    }
}

foreach($array as $value){
    if(count(explode('.',$value['hierarchy'])) == 2){
        if($value['type'] == 'category_label'){
            foreach($array_tree as $key =>  $tree){
                if($tree['hierarchy'] == explode('.',$value['hierarchy'])[0]){
                    array_push($array_tree['children'],$value);
                }
            }
        } else {
            foreach($array_tree as $key =>  $tree){
                if($tree['hierarchy'] == explode('.',$value['hierarchy'])[0]){
                    array_push($array_tree[$key],$value);
                }
            }
        }
    }
}

foreach($array as $value){
    if(count(explode('.',$value['hierarchy'])) == 3){
        if($value['type'] == 'item'){
            foreach($array_tree as $key => $tree){
                foreach($tree as $item){
                    if($item['hierarchy'] == explode('.',$value['hierarchy'],2)[1]){
                        array_push($array_tree[$key]['children'],$value);
                    }
                }
            }
        }
    }
}

Answer 2

您可以首先将所有项目按其层次结构键入一个新的关联数组中。然后再次迭代这些项目，并删除hierarchy 的最后一部分以获取父项目的键，将其定位在新的关联数组中，并将其添加到其子项中。如果它没有父级，则将其添加到结果数组中。

由于您的hierarchy 分隔符是一个点，您可以使用pathinfo 函数从中删除最后一个“扩展名”：

事实证明，您的层次结构编号不是唯一的（例如“1.1”）。如果希望父节点可以具有与“item”类型的兄弟节点相同的编号，但 same 类型的两个节点将永远不会具有相同的层次结构，则通过组合键节点类型和层次结构：

foreach ($array as $item) $keyed[$item["type"] . $item["hierarchy"]] = $item;

foreach ($keyed as &$item) {
    $parent = pathinfo($item["hierarchy"], PATHINFO_FILENAME);
    if ($parent == $item["hierarchy"]) $result[] =& $item;
    else $keyed["category_label$parent"]["children"][] =& $item;
}

运行后，$result 将具有所需的结构。

不过，我建议使层次结构代码独一无二，这样它们就不会在类型之间发生冲突。那么上面的代码可以改成：

foreach ($array as $item) $keyed[$item["hierarchy"]] = $item;

foreach ($keyed as &$item) {
    $parent = pathinfo($item["hierarchy"], PATHINFO_FILENAME);
    if ($parent == $item["hierarchy"]) $result[] =& $item;
    else $keyed[$parent]["children"][] =& $item;
}