嵌套集、php数组和转换

Question

对于这个空间树1) http://blog.thejit.org/wp-content/jit-1.0a/examples/spacetree.html，我需要将我的嵌套集合结构(mysql)转换成json

我发现这个函数可以从嵌套的集合中创建数组: 2) http://semlabs.co.uk/journal/converting-nested-set-model-data-in-to-multi-dimensional-arrays-in-php

我也可以用php函数json_encode把PHP数组转换成json。

我的问题:函数nestify (来自第二个链接)给我的并不完全是我需要的。我需要这样的东西：http://pastebin.com/m68752352

你能帮我修改函数"nestify“，让它给我正确的数组吗？

下面是这个函数的最后一次：

function nestify( $arrs, $depth_key = 'depth' )
    {
        $nested = array();
        $depths = array();

        foreach( $arrs as $key => $arr ) {
            if( $arr[$depth_key] == 0 ) {
                $nested[$key] = $arr;
                $depths[$arr[$depth_key] + 1] = $key;
            }
            else {
                $parent =& $nested;
                for( $i = 1; $i <= ( $arr[$depth_key] ); $i++ ) {
                    $parent =& $parent[$depths[$i]];
                }

                $parent[$key] = $arr;
                $depths[$arr[$depth_key] + 1] = $key;
            }
        }

        return $nested;
    }

Answer 1

下面这段代码可以解决这个问题，改编自我在网上找到的一些PHP Doctrine代码：

function toHierarchy($collection)
{
        // Trees mapped
        $trees = array();
        $l = 0;

        if (count($collection) > 0) {
                // Node Stack. Used to help building the hierarchy
                $stack = array();

                foreach ($collection as $node) {
                        $item = $node;
                        $item['children'] = array();

                        // Number of stack items
                        $l = count($stack);

                        // Check if we're dealing with different levels
                        while($l > 0 && $stack[$l - 1]['depth'] >= $item['depth']) {
                                array_pop($stack);
                                $l--;
                        }

                        // Stack is empty (we are inspecting the root)
                        if ($l == 0) {
                                // Assigning the root node
                                $i = count($trees);
                                $trees[$i] = $item;
                                $stack[] = & $trees[$i];
                        } else {
                                // Add node to parent
                                $i = count($stack[$l - 1]['children']);
                                $stack[$l - 1]['children'][$i] = $item;
                                $stack[] = & $stack[$l - 1]['children'][$i];
                        }
                }
        }

        return $trees;
}