检查 XML 元素标签是否为空 [英] check if XML element tag empty
问题描述
我有一个包含空元素标签的 XML:
I have an XML that has empty element tags:
<manufacturer>
<![CDATA[ ]]>
</manufacturer>
我试图避免将此元素标记添加到我的数据库中，但我做不到.这是我的整个代码，它也作为 cronjob 运行......为了更新我的记录......我看到了一些关于你们的有用信息......但我不明白我错过了什么......并且找不到解决方案.. 我的数据库中仍然有制造商空记录，尽管我正在检查(或至少我正在尝试检查)制造商元素是否为空，但不要添加它做数据库 .. 你能给我一些解释或解决这个问题的方法吗?谢谢！！
I am trying to avoid adding this element tag to my DB, but I could not. This is my whole code that is also running as a cronjob.. in order to update my records.. I saw some userful information about you guys... but I could not understand what I am missing.. and could not find a solution.. I still have manufacturer empty records in my DB, although I am checking (or at least I am trying to check) if manufacturer element is empty do not add it do DB.. Could you give me some explanation or solution to this problem? thanks!!
<?php
header('Content-type: text/html; charset=UTF-8') ;
//connection info here
// Create connection
$conn = new mysqli($servername, $dbuser, $password, $dbname,3306);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
// Change character set to utf8
$conn->set_charset("utf8");
date_default_timezone_set('Europe/Athens');
//$date = strtotime("now");
$sql = $conn->query("SELECT * FROM business_xml WHERE activate=1 AND business_id=54"); //business_id = 54
while($exe_xml = mysqli_fetch_object($sql)) {
$value_of = 0;
$diff = 0;
if($exe_xml->date_modified == NULL) {
$value_of = 1;
}
else {
$modified = $exe_xml->date_modified;
$now = strtotime("now");
$diff = $now - $modified;
}
//if($diff > 3599 || $value_of == 1) { //$diff = 3600 means one hour difference
//get values first
$date_modified = strtotime("now");
$business_id = $exe_xml->business_id;
$xml_link = $exe_xml->xml_link;
//UPDATE modified date
$update_business_xml = $conn->query('UPDATE business_xml SET date_modified="' . $date_modified . '" WHERE business_id="' . $business_id . '"');
$product_xml_link = $xml_link;
$product_xml_link = $conn->real_escape_string($product_xml_link);
$product_xml_link = trim(stripslashes($product_xml_link));
if($product_xml_link) {
$count_errors = 0;
//query to find products ids
//if exists UPDATE, else INSERT
$query_ids = $conn->query('SELECT pid FROM products WHERE business_id=54');
$rows_ids = mysqli_num_rows($query_ids);
$count_id = 0;
if($rows_ids > 0) {
while($exe_ids = mysqli_fetch_object($query_ids)) {
$arr_ids[$count_id] = $exe_ids->pid;
$count_id++;
}
}
$reader = new XMLReader();
$reader->open($product_xml_link);
while($reader->read()) {
if($reader->nodeType == XMLReader::ELEMENT && $reader->name == 'product' ) {
//For each node to type "product"
$product = new SimpleXMLElement($reader->readOuterXml());
$pid = $product->id;
$name = $product->name;
$name = mb_strtolower($name);
$mpn = $product->mpn;
$ean = $product->ean;
$sku = $product->sku;
$link = $product->link;
$price = $product->price;
$category_id = $product->category->attributes();
$category_path = $product->category;
$category_path = mb_strtolower($category_path);
$image = $product->image;
$availability = $product->availability;
$size = $product->size;
$size = mb_strtolower($size);
$color = $product->color;
$color = mb_strtolower($color);
$weight = $product->weight;
$description = $product->description;
$manufacturer = $product->manufacturer;
$manufacturer = trim($manufacturer);
$instock = "Y";
$product_image = $image;
$check_product_url = $link;
$exist_pids = 0;
if(empty($pid) || empty($image) || empty($price) || empty($name) || empty($link) || empty($manufacturer)) {
//update status for this pid product, cause there is an empty value, which it is required
$update_business_xml = $conn->query('UPDATE products SET status=0 WHERE business_id="' . $business_id . '" AND pid= "' . $pid . '"');
$count_errors++;
}
else {
$date_modified = strtotime("now");
for($i = 0; $i < $rows_ids; $i++) {
if($arr_ids[$i] == $pid) {
$exist_pids = 1;
}
} //end for loop
if($category_id == 613 || $category_id == 604 || $category_id == 635) {
//forbidden products
//update status for this pid product, cause there is an empty value, which it is required
$update_business_xml = $conn->query('UPDATE products SET status=0 WHERE business_id="' . $business_id . '" AND pid= "' . $pid . '"');
$count_errors++;
}
else {
if($exist_pids == 1) {
$update_business_xml = $conn->query('UPDATE products SET name="' . $name . '", price="' . $price . '", product_link="' . $link . '", image="' . $image . '", size="' . $size . '", color="' . $color . '" date_modified="' . $date_modified . '" WHERE business_id="' . $business_id . '" AND pid= "' . $pid . '"');
}
else {
//$date_added = strtotime("now");
$status = 1;
$date = date('d-m-Y H:i:s');
$insert_business_xml = $conn->query('INSERT INTO products (business_id,pid,name,category,product_link,price,size,color,weight,description,manufacturer,mpn,ean,image,sku,instock,availability,status,date_added) VALUES("'.$business_id.'",
"' . mysqli_real_escape_string($conn,stripslashes($pid)) . '",
"' . mysqli_real_escape_string($conn,stripslashes($name)) . '",
"' . mysqli_real_escape_string($conn,stripslashes(trim($category_path))) . '",
"' . $check_product_url . '",
"' . mysqli_real_escape_string($conn,stripslashes($price)) . '",
"' . mysqli_real_escape_string($conn,stripslashes(trim(strtolower($size)))) . '",
"' . mysqli_real_escape_string($conn,stripslashes(trim(strtolower($color)))) . '",
"' . mysqli_real_escape_string($conn,stripslashes(trim($weight))) . '",
"' . mysqli_real_escape_string($conn,stripslashes(trim($description))) . '",
"' . mysqli_real_escape_string($conn,stripslashes(trim(strtolower($manufacturer)))) . '",
"' . mysqli_real_escape_string($conn,stripslashes(trim($mpn))) . '",
"' . mysqli_real_escape_string($conn,stripslashes(trim($ean))) . '",
"' . $product_image . '",
"' . mysqli_real_escape_string($conn,stripslashes(trim($sku))) . '",
"' . mysqli_real_escape_string($conn,stripslashes($instock)) . '",
"' . mysqli_real_escape_string($conn,stripslashes($availability)) . '",
"' . $status . '", "' . $date . '")');
}
}
}
} //end if $reader-nodeType
} //end while loop
$reader->close();
$insert_messages = "Your XML file has been updated successfully! We found <strong>" . $count_errors . "</strong> errors. In case errors found, please check your dashboard!";
echo $insert_messages;
} //end $product_xml_link
//} //end if diff 3600
} //end while loop
?>
推荐答案
其实制造商"元素不是空的.它包含三个节点.
Actually the "manufacturer" element is not empty. It contains three nodes.
$xml = <<<'XML'
<manufacturer>
<![CDATA[ ]]>
</manufacturer>
XML;
$document = new DOMDocument();
$document->loadXml($xml);
foreach ($document->documentElement->childNodes as $childNode) {
var_dump(get_class($childNode), $childNode->textContent);
}
输出:
string(7) "DOMText"
string(1) "
"
string(15) "DOMCdataSection"
string(1) " "
string(7) "DOMText"
string(1) "
"
文本节点是空白节点，它们包含换行符.DOM 中的一切都是一种节点，甚至属性值也是属性节点的文本子节点.您可以避免在 DOM 中出现空白节点.在解析之前设置 $preserveWhiteSpace 属性.
The text nodes are whitespace nodes, they contain the linebreaks. Everything in a DOM is a kind of node, even the attribute values are text child nodes of the attribute nodes. You can avoid having whitespace nodes in your DOM. Set the $preserveWhiteSpace property before parsing.
$document = new DOMDocument();
$document->preserveWhiteSpace = FALSE;
$document->loadXml($xml);
foreach ($document->documentElement->childNodes as $childNode) {
var_dump(get_class($childNode), $childNode->textContent);
}
输出:
string(15) "DOMCdataSection"
string(1) " "
这样就只剩下 CDATA 部分了.它包含一个空间.您可以在文本内容上使用 trim() 并验证结果是否为空字符串以查看它是否为空".您可以直接在制造商"元素节点上执行此操作:
With that only the CDATA section is left. It contains a space. You could use trim() on the text content and validate that the result is an empty string to see if it is "empty". You can do that directly on the "manufacturer" element node:
$document = new DOMDocument();
$document->loadXml($xml);
var_dump(trim($document->documentElement->textContent) === '');
输出:
bool(true)
另一种方法是使用normalize-space().它用一个空格替换所有空格组并修剪结果.所以要获取节点的文本内容，如果它不仅包含空格:
Another way is to use the normalize-space(). It replaces all groups of whitespaces with a single space and trims the result. So to fetch the text content of a node if it contains not only whitespaces:
$xml = <<<'XML'
<list>
<manufacturer>
<![CDATA[ ]]>
</manufacturer>
<manufacturer>
<![CDATA[ not only spaces ]]>
</manufacturer>
</list>
XML;
$document = new DOMDocument();
$document->loadXml($xml);
$xpath = new DOMXpath($document);
foreach ($xpath->evaluate('//manufacturer[normalize-space(.) != ""]') as $manufacturer) {
var_dump(trim($manufacturer->textContent));
}
输出:
string(15) "not only spaces"
这篇关于检查 XML 元素标签是否为空的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
