Xpath for a REST response with Keys - php

I am trying to use Xpath to find a username value from a REST response. When I use
$data = new simpleXMLElement($response->getBody());
$matches = $data->xpath('//KEY[#name="username"]');
I get
array(1) {
[0]=>
object(SimpleXMLElement)#7 (2) {
["#attributes"]=>
array(1) {
["name"]=>
string(8) "username"
}
["VALUE"]=>
string(5) "guest"
}
}
My question is, what is the Xpath expression to get only the value to display? in this example it is guest, but will change depending on the user.
Any suggestions greatly appreciated.
XML structure below.
<?xml version="1.0" encoding="UTF-8" ?>
<RESPONSE>
<MULTIPLE>
<SINGLE>
<KEY name="id">
<VALUE>1</VALUE>
</KEY>
<KEY name="username">
<VALUE>guest</VALUE>
</KEY>
<KEY name="firstname">
<VALUE>Guest user</VALUE>
</KEY>

Not possible with SimpleXML. The xpath method will always return an Array.
But you can do:
$keys = simplexml_load_string($xml);
echo current($keys->xpath('//KEY[#name="username"]/VALUE'));
demo
Or use DOM. The following will return the string immediately:
$dom = new DOMDocument;
$dom->loadXml($xml);
$xpath = new DOMXPath($dom);
echo $xpath->evaluate('string(//KEY[#name="username"]/VALUE)');
demo

I am not sure if simpleXml can evaluate this expression, but any compliant XPath implementation will:
string(//KEY[#name="username"]/VALUE)
When this expression is evaluated, the result is the string value of the Value element that is a child of the (first in document order) KEY element that has a name attribute, whose string value is "username".
Also, if the structure of the XML document is known, then it may be more efficient (fast) not to use //:
string(/RESPONSE/MULTIPLE/SINGLE/KEY[#name="username"]/VALUE)

Related

PHP iterating over an XML

How can I convert XML to an array that I can iterate over.
Here is the example of my XML
<user>
<student>yes</student>
<id>1</id>
<name>John</name>
</user>
<user>
<student>yes</student>
<id>1</id>
<name>Billy</name>
</user>
My php looks like this
$tmpTemplates = new XDomDocument();
$tmpTemplates->load('.....myFile.xml');
$xPath = new DomXPath($tmpTemplates);
$query = "//user[student='yes']";
$tmpTemplate = $xPath->query($query);
What I want to be able to do is
foreach($tmpTemplate as $tt){
var_dump($tt->student);
var_dump($tt->id);
var_dump($tt->name);
}
Now I'm only able to print out nodeValue which gives me something like this:
yes
1
John
How can I make it an array or an object so I can apprach each value by its key?
You used the same id for both records in your example, so I changed the id of the first one and added a document element.
<users>
<user>
<student>yes</student>
<id>2</id>
<name>John</name>
</user>
<user>
<student>yes</student>
<id>1</id>
<name>Billy</name>
</user>
</users>
Use DOMXpath:evaluate() to fetch the details, the second argument is the context node for the expression.
$document = new DOMDocument();
$document->loadXml($xmlString);
$xPath = new DomXPath($document);
$students = [];
foreach ($xPath->evaluate("//user[student='yes']") as $student) {
$id = $xPath->evaluate('string(id)', $student);
$students[$id] = [
'id' => $id,
'name' => $xPath->evaluate('string(name)', $student)
];
}
var_dump($students);
Output:
array(2) {
[2]=>
array(2) {
["id"]=>
string(1) "2"
["name"]=>
string(4) "John"
}
[1]=>
array(2) {
["id"]=>
string(1) "1"
["name"]=>
string(5) "Billy"
}
}
The return value depends on the expression. A location path like //user[student='yes'] or name returns a DOMNodeList. But you can cast the node list directly in Xpath. string(name) will return the contents of the first name child node or an empty string.
How can I make it an array or an object so I can apprach each value by its key?
Just for clarification, you've got an object so far, it's the SimpleXMLElement and you're using then $tt variable to access it:
...
var_dump($tt->student);
var_dump($tt->id);
var_dump($tt->name);
...
Now that $tt variable comes from another variable, namely by iterating over it, and the other variable is named $tmpTemplate:
...
foreach ($tmpTemplate as $tt) {
var_dump($tt->student);
...
That variable by the way is an array. So you can use it by using the index (starting at zero) to access each <user> element containing a <student> child-element with the value "student" in document-order (as you formulated the xpath for it):
$tmpTemplate[0] contains the first user SimpleXMLElement.
$tmpTemplate[1] contains the second user SimpleXMLElement.
... and so on and so forth.
I hope this makes this a bit more visible.
Try with this php function
xml_parse_into_struct
sample from php manual
<?php
$simple = "<para><note>simple note</note></para>";
$p = xml_parser_create();
xml_parse_into_struct($p, $simple, $vals, $index);
xml_parser_free($p);
echo "Index array\n";
print_r($index);
echo "\nVals array\n";
print_r($vals);
?>
You can use simplexml_load_file, which convert xml to object.
For instance :
$users = simplexml_load_file("users.xml");
foreach($users as $user) {
...
}

Extract Data off multiple XML row

I have a really weird XML response and i need to extract it's data. I need to get the data in the "value" attribute but i need to choose them according to their "key" attributes.
This is how it looks like
<phone>
2125556666
</phone>
<State>
ny
</State>
<Response>
<data key="Supported" value="Yes"/>
<data key="Host" value="Remote"/>
<data key="WholeProductList">
<data key="Product" value="a-z44"/>
<data key="Product" value="c-k99"/>
<data key="Product" value="e-b089"/>
<data key="Product" value="z-p00"/>
<data key="Product" value="r-333"/>
<data key="Product" value="t-RS232"/>
<data key="Product" value="4-lve"/>
<data key="Product" value="Shutdown"/>
</data>
</Response>
In PHP i currenty have
$xmltmp = new DomDocument;
$xmltmp->loadXml($response);
$phone = $xmlresponse->getElementsByTagName('phone')->item(0)->nodeValue;
$state = $xmlresponse->getElementsByTagName('state')->item(0)->nodeValue;
echo $phone;
echo $state;
This currently outputs both phone number and state. It works fine.
Now i need to know if the "Supported" key's value is Yes or No, and if it's Yes, i need to get all "Products". I'm kinda stuck because i am having a hard time making the foreach statement and then checking the "key" attribute value.
Thanks!
Your XML is invalid. An XML document always needs a single document element node.
Example:
<root>
<phone>2125556666</phone>
<State>ny</State>
<Response>
<data key="Supported" value="Yes"/>
...
</data>
</Response>
</root>
The easiest way to fetch data from a DOM is XPath. In PHP that is provided by the DOMXPath class and part of the ext/dom. DOMXPath::evaluate() allows you to fetch node lists or scalar values from the DOM document.
$dom = new DOMDocument;
$dom->loadXml($xml);
$xpath = new DOMXPath($dom);
$phone = $xpath->evaluate('string(/*/phone)');
$state = $xpath->evaluate('string(/*/State)');
var_dump($phone, $state);
Output:
string(10) "2125556666"
string(2) "ny"
An expression like /*/phone selects all phone element child nodes inside the document element. string(/*/phone) casts the first found node into a string and return that. If no node was found, it will return an empty string.
The XPath expression for the supported status is slightly more complex. Conditions for nodes are provided in []. It is possible to compare the result directly in XPath. The return value will be an boolean.
$supported = $xpath->evaluate('/*/Response/data[#key="Supported"]/#value = "Yes"');
var_dump($supported);
Output:
bool(true)
If the expression returns a node list you can iterate it with foreach().
$nodes = $xpath->evaluate(
'/*/Response/data[#key="WholeProductList"]/data[#key="Product"]/#value'
);
$products = [];
foreach ($nodes as $attributeNode) {
$products[] = $attributeNode->value;
}
var_dump($products);
Output:
array(8) {
[0]=>
string(5) "a-z44"
[1]=>
string(5) "c-k99"
[2]=>
string(6) "e-b089"
[3]=>
string(5) "z-p00"
[4]=>
string(5) "r-333"
[5]=>
string(7) "t-RS232"
[6]=>
string(5) "4-lve"
[7]=>
string(8) "Shutdown"
}
This won't quite work "as is" since I don't know what the actual structure of the XML document is, but in short you map the XML nodes to XPath like //root/node/child_node/#attribute and so on.
It should also have some sanity (not null) type checking in.
$xmltmp = new DomDocument;
$xmltmp->loadXml($response);
$xQuery = new DOMXPath($xmltmp);
//not sure what your root node is so the query path is probably wrong
$supported = $xQuery->query('/Response/data[#key="Supported"]/#value')->value;
You can also replace:
$phone = $xmlresponse->getElementsByTagName('phone')->item(0)->nodeValue;
$state = $xmlresponse->getElementsByTagName('state')->item(0)->nodeValue;
With something like (again - without the full structure of the XML document the path itself is probably not quite right):
$phone = $xQuery->query('/phone')->item(0)->nodeValue;
$state = $xQuery->query('/State')->item(0)->nodeValue;

var_dump for DOMNodeList printout unexpected result

I have a xml file I load it as the following:
//$file the file system path of the xml file
function getTopicsList($file){
$doc = new DOMDocument();
$doc->load( $file );
var_dump($doc->getElementsByTagName('topic'));
return $doc->getElementsByTagName('topic');
}
The loaded xml file contents is something like the following:
<?xml version="1.0" encoding="UTF-8"?>
<topics>
<topic>
<title>Title1</title>
<keywords>"Some Keys"</keywords>
</topic>
<topic>
<title>The Title</title>
<keywords>Another Key</keywords>
</topic>
<topic>
<title>A Title</title>
<keywords>Key two</keywords>
</topic>
</topics>
The var_dump() in the above code just printout limited information such as:
object(DOMNodeList)#30 (1) {
["length"]=>
int(3)
}
I expected that it should print at least the properties of that object i.e the xml tags and its values. I tried to use other functions such as print_r() and var_export() but there is no details I want.
No, this is node list. You can iterate it with foreach or access nodes using the item() method.
Node lists are used at different places, getElementsByTagName() is one, another is the $childNodes property. Xpath expressions return node lists, too.
Be aware that the nodes can be not only elements but several node types. Like text, cdata section or attribute.
You can use var_dump() to dump a single node. This works with PHP >= 5.3.11 or >= 5.4.1.
$dom = new DOMDocument();
$dom->loadXML('<foo/>');
var_dump($dom->documentElement);
Output:
object(DOMElement)#2 (18) {
["schemaTypeInfo"]=>
NULL
["tagName"]=>
string(3) "foo"
["textContent"]=>
string(0) ""
["baseURI"]=>
string(1) "/"
["localName"]=>
string(3) "foo"
["prefix"]=>
string(0) ""
["ownerDocument"]=>
...

Working through the XML Dom?

I am new to the xml dom and I am trying to to retrieve the value in the '' tags.
The problem is I am not sure how to work down to that level in the dom.
I have tried to do something like this:
itemXML.getElementById("gender").getElementsByTagName("item").nodeValue;
But that returns 'undefined', how would I specify which tag I want to retrieve the value of?
Below is the contents of my xml document:
<dataFields>
<items id="gender">
<item>Male</item>
<item>Female</item>
</items>
<items id="age">
<item>0-3 years</item>
<item>3-6 years</item>
<item>7-16 years</item>
<item>17-25 years</item>
<item>26-40 years</item>
<item>41-65 years</item>
<item>65+ years</item>
</items>
$xpath = new DOMXPath($itemXML);
$genderItems = $xpath->query('/dataFields/items[#id="gender"]/item');
foreach ($genderItems as $genderItem) {
echo $genderItem->nodeValue . "\n"; // "Male", "Female"
}
$items = $doc->getElementsByTagName('item');
The id attribute in XML without a namespace prefix is just a normal attribute, only in html it is the identifier. So in xml documents, the attribute name would have to be "xml:id" to be found by getElementById(). The getElementsByTagName() method returns a list of element nodes, not just one. You will have to use foreach() or the item() method to access the elements in the list.
But here is an easier way. DOMXpath:evaluate() allows you to use xpath expression to fetch nodes and values from a DOM.
Here is some demo source:
$xml = <<<'XML'
<dataFields>
<items id="gender" xml:id="xml_gender">
<item>Male</item>
<item>Female</item>
</items>
<items id="age">
<item>0-3 years</item>
<item>3-6 years</item>
<item>7-16 years</item>
<item>17-25 years</item>
<item>26-40 years</item>
<item>41-65 years</item>
<item>65+ years</item>
</items>
</dataFields>
XML;
$dom = new DOMDocument();
$dom->loadXml($xml);
// difference between id and xml:id
var_dump(
$dom->getElementById('gender'),
get_class($dom->getElementById('xml_gender'))
);
/* Output:
NULL
string(10) "DOMElement"
*/
// getElementsByTagName returns a node list
var_dump(
get_class($dom->getElementById('xml_gender')->getElementsByTagName('item'))
);
/* Output:
NULL
string(11) "DOMNodeList"
*/
// you can iterate node lists
foreach ($dom->getElementById('xml_gender')->getElementsByTagName('item') as $item) {
var_dump($item->nodeValue);
}
/* Output:
string(4) "Male"
string(6) "Female"
*/
// it is easier with xpath
$xpath = new DOMXpath($dom);
foreach ($xpath->evaluate('//items[#id = "gender"]/item') as $item) {
var_dump($item->nodeValue);
}
/* Output:
string(4) "Male"
string(6) "Female"
*/
// DOMXpath::evaluate() can be used to fetch values directly, too.
var_dump(
$xpath->evaluate('string(//items[#id = "gender"]/item[2])')
);
/* Output:
string(6) "Female"
*/

PHP, SimpleXML arrays. Unanticipated casting of an array to a string

Sample XML:
<root>
<ratings>3</ratings>
<ratings>5</ratings>
<ratings>7</ratings>
</root>
The following code is the basis for my small application, it works as would be expected:
<?php
// $xml is some simplexml object
sizeof($xml->ratings); //3
foreach($xml->ratings as $rating){
echo($rating->value."::"); //this echoes all 3 rating values: 3::5::7
}
?>
This next code, which I would normally consider to be equivalent is not. And I have no idea why:
<?php
// $xml is some simplexml object
$ratings = $xml->ratings;
sizeof($ratings); //3, all is well so far
foreach($ratings as $rating){
echo($rating."::");
/*this echoes a never-ending list of ratings,
looking like 3::5::5::5::5::5::5::5...... */
}
?>
My feeling is that the assignment operator is casting the array of simplexml objects (ratings objects) as something odd, but have no clue as to how.
Other little hints:
var_dump($xml);
/* Output is:
object(SimpleXMLElement)#7 (1) {
["ratings"]=>
array(3) {
[0]=>
string(1) "3"
[1]=>
string(1) "5"
[2]=>
string(1) "7"
}
}
*/
var_dump($ratings);
/* Output is:
object(SimpleXMLElement)#6 (1) {
[0]=>
string(1) "3"
}
*/
Your echos are not the same:
echo($rating."::");
should be
echo($rating->value."::");
Ok, cleaning up some of my own work. After attempting to simplify my issue more, I was not able to prove it. After messing with the actual code, I assume this means I have some sort of mutating object elsewhere in my app that is going bonkers and creating weird results in this xml parsing. Sorry for the confusion and needless question (I guess this proves why i'm trying to refactor some of my complexity out of this app).
As a parting gift, here is the test-suite of code that I used (from simple to more realistic) that I used to prove that all worked as advertised:
<?php
$string = <<<XML
<?xml version='1.0'?>
<root>
<ratings>3</ratings>
<ratings>5</ratings>
<ratings>7</ratings>
</root>
XML;
$xml = simplexml_load_string($string);
var_dump($xml);
echo("Size:".sizeof($xml->ratings)."\n");
foreach($xml->ratings as $rating){
echo($rating."::");
}
echo("\n"."------"."\n");
$ratings = $xml->ratings;
echo("Size:".sizeof($ratings)."\n");
foreach($ratings as $rating){
echo($rating."::");
}
echo("\n\n\n\n"."||||New Example||||"."\n\n\n\n");
$stringthree = <<<XML
<root attr1="val" attr2="desc">
<field-one>val</field-one>
<elm-two attr-name="foo">elmTwoVal1</elm-two>
<elm-three>elmThreeVal1</elm-three>
<elm-two attr-name="bar">elmTwoVal2</elm-two>
<elm-three>elmThreeVa2</elm-three>
<elm-two attr-name="bear">elmTwoVal3</elm-two>
<elm-three>elmThreeVal3</elm-three>
</root>
XML;
$xmlthree = simplexml_load_string($stringthree);
var_dump($xmlthree);
echo("Size:".sizeof($xmlthree->{'elm-two'})."\n");
foreach($xmlthree->{'elm-two'} as $elm){
echo($elm."::");
}
echo("\n"."------"."\n");
$elmMain = $xmlthree->{'elm-two'};
echo("Size:".sizeof($elmMain)."\n");
foreach($elmMain as $elm){
echo($elm."::");
}
?>

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