Get elements from a XML content by PHP - php

Question

I am trying to get elements from this XML content but returns empty:
<results>
<error>
<string>i</string>
<description>Make I uppercase</description>
<precontext></precontext>
<suggestions>
<option>I</option>
</suggestions>
<type>grammar</type>
</error>
</results>
And this is my code to extract element type of grammar :
$dom = new DOMDocument();
$dom->loadXml($output);
$params = $dom->getElementsByTagName('error'); // Find Sections
$k=0;
foreach ($params as $param) //go to each section 1 by 1
{
if($param->type == "grammar"){
echo $param->description;
}else{
echo "other type";
}
Problem is the script returns empty.

Answer 1

you can use simplexml_load_string()
$output = '<results>
<error>
<string>i</string>
<description>Make I uppercase</description>
<precontext></precontext>
<suggestions>
<option>I</option>
</suggestions>
<type>grammar</type>
</error>
</results>';
$xml = simplexml_load_string($output);
foreach($xml->error as $item)
{
//echo (string)$item->type;
if($item->type == "grammar"){
echo $item->description;
}else{
echo "other type";
}
}

Answer 2

You apparently haven't configured PHP to report errors because your code triggers:
Notice: Undefined property: DOMElement::$type
You need to grab <type> the same way you grab <error>, using DOM methods like e.g. getElementsByTagName(). Same for node value:
if ($param->getElementsByTagName('type')->length && $param->getElementsByTagName('type')[0]->nodeValue === 'grammar') {
// Feel free to add additional checks here:
echo $param->getElementsByTagName('description')[0]->nodeValue;
}else{
echo "other type";
}
Demo

Answer 3

I think is this what you want.
<?php
$output = '<results>
<error>
<string>i</string>
<description>Make I uppercase</description>
<precontext></precontext>
<suggestions>
<option>I</option>
</suggestions>
<type>grammar</type>
</error>
</results>';
$dom = new DOMDocument();
$dom->loadXml($output);
$params = $dom->getElementsByTagName('error'); // Find Sections
$k=0;
foreach ($params as $param) //go to each section 1 by 1
{
$string = $param->getElementsByTagName( "string" )->item(0)->nodeValue;
$description = $param->getElementsByTagName( "description" )->item(0)->nodeValue;
$option = $param->getElementsByTagName( "option" )->item(0)->nodeValue;
$type = $param->getElementsByTagName( "type" )->item(0)->nodeValue;
echo $type;
if($type == "grammar"){
echo $description ;
}else{
echo "other type";
}
}
?>

Answer 4

You're mixing DOM with SimpleXML. This is possible, but you would need to convert the DOM element node into a SimpleXML instance with simplexml_import_dom().
Or you use Xpath. getElementsByTagName() is a low level DOM method. Using Xpath expressions allows for more specific access with a lot less code.
$document = new DOMDocument();
$document->loadXML($xml);
$xpath = new DOMXpath($document);
foreach ($xpath->evaluate('//error') as $error) {
var_dump(
[
'type' => $xpath->evaluate('string(type)', $error),
'description' => $xpath->evaluate('string(description)', $error)
]
);
}
Output:
array(2) {
["type"]=>
string(7) "grammar"
["description"]=>
string(16) "Make I uppercase"
}
Xpath expressions allow for conditions as well, for example you could fetch all grammar errors using //error[#type = "grammar"].