組裝多維JSON對象

Question

我試圖組裝這個數據（樹結構）的JSON對象Baobab。我有以下的遞歸函數：

/* Takes the Tree (in this case, always '1') and the Parent ID where we want to start, this case, I would also start with '1' */ 
function walkTree($tree, $id) 
{ 
    /* Gets the children of that of that ID */ 
    $children = $tree->getChildren($id); 

    $data = ""; 

    /* Loop through the Children */ 
    foreach($children as $index => $value) 
    { 
      /* A function to get the 'Name' associated with that ID */ 
      $name = getNodeName($tree, $value); 

      /* Call the walkTree() function again, this time based on that Child ID */ 
      $ret = walkTree($tree, $value); 

      /* Append the string to $data */ 
      $data .= '{"data":"'.$name.'","attr": {"id" : "'.$value.'"} 
        ,"state":"closed","children": ['.$ret.']}'; 
    } 

    /* Return the final result */ 
    return $data; 
} 

這是非常接近的工作，但如你所見，有每個嵌套對象和數組之間沒有逗號，所以JSON格式不正確。大量的以下內容：

... {"data":"Personal","attr": {"id" : "4"},"state":"closed","children": []}{"data":"News-editorial","attr": {"id" : "5"},"state":"closed","children": [] ...

我認爲最好的辦法是創建一個PHP數組和json_encode()，但我不能找到一種方法，使嵌套對象工作。

Answer 1

那麼，如果你想通過級聯構建了這一點，那麼就跟蹤在第一和隨後的元素。這個修改後的代碼應該工作：

/* Takes the Tree (in this case, always '1') and the Parent ID where we want to start, this case, I would also start with '1' */ 
function walkTree($tree, $id) 
{ 
    /* Gets the children of that of that ID */ 
    $children = $tree->getChildren($id); 
    $first = true; 

    $data = ""; 

    /* Loop through the Children */ 
    foreach($children as $index => $value) 
    { 
    /* A function to get the 'Name' associated with that ID */ 
    $name = getNodeName($tree, $value); 

    /* Call the walkTree() function again, this time based on that Child ID */ 
    $ret = walkTree($tree, $value); 

    /* Append the string to $data */ 
    if($first) { 
     $first = false; 
    } else { 
     /*add comma for each element after the first*/ 
     $data .= ','; 
    } 
    $data .= '{"data":"'.$name.'","attr": {"id" : "'.$value.'"},"state":"closed","children": ['.$ret.']}'; 
    } 

    /* Return the final result */ 
    return $data; 
} 

Answer 2

您可以舒緩這樣反而

$data = array(); 

foreach($children as $index => $value) 
{ 
    $node = array(); 
    $node['data'] = getNodeName($tree, $value) ; 
    $node['attr'] = array("id"=>$value,"state"=>"closed","children"=>walkTree($tree, $value)) ; 

    $data[] = $node ; 
} 

return json_encode($data);