使用SimpleXML從XML構建JSON時出現的問題

Question

我想要得到一個書籍列表，我從XML解析並希望輸出爲JSON。

我想JSON格式爲：

[ 
    "1" : { 
     "Title": "Sidemen: The Book", 
     "ISBN": "1473648165", 
     "Rating": "4.5" 
    }, 
    ... 
] 

然而，結果出來是這樣的：

[ 
    { 
    "title":{ 
     "0":"Sidemen: The Book" 
    }, 
    "ISBN":{ 
     "0":"1473648165" 
    } 
    }, 
    { 
    "title":{ 
     "0":"DanTDM: Trayaurus and the Enchanted Crystal" 
    }, 
    "ISBN":{ 
     "0":"1409168395" 
    } 
    }, 
    { 
    "title":{ 
     "0":"Pok\u00e9mon Sun & Pok\u00e9mon Moon: The Official Strategy Guide" 
    }, 
    "ISBN":{ 
     "0":"1911015109" 
    } 
    }, 
    { 
    "title":{ 
     "0":"Guinness World Records 2017 Gamer's Edition" 
    }, 
    "ISBN":{ 
     "0":"1910561398" 
    } 
    }, 
    { 
    "title":{ 
     "0":"Minecraft: Blockopedia: An Official Minecraft Book from Mojang" 
    }, 
    "ISBN":{ 
     "0":"1405273534" 
    } 
    }, 
    { 
    "title":{ 
     "0":"Final Fantasy XV - The Complete Official Guide - Collector's Edition" 
    }, 
    "ISBN":{ 
     "0":"1911015001" 
    } 
    }, 
    { 
    "title":{ 
     "0":"Harry Potter: Collectible Quidditch Set" 
    }, 
    "ISBN":{ 
     "0":"076245945X" 
    } 
    }, 
    { 
    "title":{ 
     "0":"Pok\u00e9mon Go The Unofficial Field Guide: Tips, tricks and hacks that will help you catch them all!" 
    }, 
    "ISBN":{ 
     "0":"1783707712" 
    } 
    }, 
    { 
    "title":{ 
     "0":"Minecraft 2017 Annual (by GamesMaster) (2017 Annuals)" 
    }, 
    "ISBN":{ 
     "0":"0995495025" 
    } 
    }, 
    { 
    "title":{ 
     "0":"World of Warcraft The Official Cookbook" 
    }, 
    "ISBN":{ 
     "0":"1785654349" 
    } 
    } 
] 

我似乎無法弄清楚這是爲什麼不做我想做的事（因爲我是一個noob）。這是用PHP生成的，如下所示：

$bookList = array(); 
$id = 0; 
foreach ($parsed_xml->Items->Item as $item) { 
    $response = file_get_contents($GoodReadsProductLink); 
    $parsed_xml = simplexml_load_string($response); 

    $currentBook = array(
    "title" => $item->ItemAttributes->Title, 
    "ISBN" => $item->ItemAttributes->ISBN, 
    "Rating" => $item->ItemAttributes->Rating 
); 

    $bookList[$id] = $currentBook; 

    $id++; 
} 

$jsonOutput = json_encode($bookList); 


var_dump($jsonOutput); 

任何人都可以看到問題，並幫助我正確地格式化JSON輸出？

Answer 1

CastSimpleXmlElement對象to string，並使用JSON_FORCE_OBJECT選項。

例子。

$xml = <<<'XML' 
<Items> 
    <Item Title="Book Title 1" ISBN="ISBN 1" Rating="4.5"/> 
    <Item Title="Book Title 2" ISBN="ISBN 2" Rating="5.0"/> 
</Items> 
XML; 
$doc = simplexml_load_string($xml); 

$id = 0; 
$books = []; 
foreach ($doc as $item) { 
    if (! $attr = $item->attributes()) { 
    continue; 
    } 

    if (empty($attr['Title']) || empty($attr['ISBN']) || empty($attr['Rating'])) { 
    continue; 
    } 

    $books[++$id] = [ 
    'title' => (string)$attr['Title'], 
    'ISBN' => (string)$attr['ISBN'], 
    'Rating' => (string)$attr['Rating'], 
    ]; 
} 

echo $json = json_encode($books, JSON_FORCE_OBJECT | JSON_PRETTY_PRINT); 

輸出

{ 
    "1": { 
     "title": "Book Title 1", 
     "ISBN": "ISBN 1", 
     "Rating": "4.5" 
    }, 
    "2": { 
     "title": "Book Title 2", 
     "ISBN": "ISBN 2", 
     "Rating": "5.0" 
    } 
}