php資料夾樹狀目錄的實現

需要實現的效果：

資料表結構：

代碼：

#### 檔案夾操作    ## 檔案夾類    class Folder{        public $id;        public $parent_id;        public $name;        public $children = array();        function __construct($id,$parent_id,$name){            $this->id = $id;            $this->parent_id = $parent_id;            $this->name = $name;        }    }    ## 資料夾樹狀目錄    function folder_tree(){        global $domain_id;        global $mailbox_id;        $folder_arr = mysql::select("select id,parent_id,name from wm_netdisk_folder where domain_id=$domain_id and mailbox_id=$mailbox_id");        $folders = array();        # 轉換為Folder實體        foreach($folder_arr as $key=>$value){            $id = $value['id'];            $parent_id = $value['parent_id'];            $name = $value['name'];            $folders[] = new Folder($id,$parent_id,$name);        }                # 頂級folder id        $top_id = 0;        # tree的第一層資料        $top = array();        # 其他資料        $table = array();        foreach($folders as $key=>$value){            if($value->parent_id==$top_id){                $top[] = $value;            }else{                $table[] = $value;            }        }        tree_help($top,$table);        return $top;    }    ## folder_tree輔助函數(遞迴)    function tree_help(&$top,&$table){        foreach($top as $a=>$b){            $id = $b->id;            foreach($table as $c=>$d){                $parent_id = $d->parent_id;                if($id==$parent_id){                    $b->children[] = $d;                    $record[] = $parent_id;                }            }            tree_help($b->children,$table);        }    }        ## 將folder_tree格式化為option html片段(遞迴)    $chrs = array('│','├','└','&nbsp;');    function to_html($datas,$base_line,&$rs){        global $chrs;        $len = count($datas);        $count = 0;        foreach($datas as $key=>$value){            $count++;            # 層級分割串            $line = '';            if($count == $len){                $line = $base_line.$chrs[2];            }else{                $line = $base_line.$chrs[1];            }            $id = $value->id;            $name = $value->name;            $pid = $value->parent_id;            $option = "<option value='$id' data-pid='$pid'>$line$name</option>";                        $rs[] = $option;            if(count($value->children)>0){                if($count == $len){                    $line = $base_line.$chrs[3];                }else{                    $line = $base_line.$chrs[0];                }                to_html($value->children,$line,$rs);            }        }    }

　　

思路：

1. 首先從資料表中取得所有檔案夾資訊。

2. 分組頂層(parent_id=0) as $top和其他資料 as $table。

3.  遍曆$top，在$table中找parent_id=$top->id的項，加入到$top->children中，然後對$top->children進行相同的遞迴，直到把$table中所有資料進行分類。

4. 3中得到的資料結構大概是:[{"id":x,"name":y,"children":[...]}]

5 .把3中得到的資料格式化為所需要的html片段。

 

和python,javascript不同，php數組在函數間傳遞時候傳遞的是副本，如果需要保持引用，就在形參上前加&。