I want to find the attribute of the last node in the xml file.
the following code find's the attribute of the first node. Is there a way to find the last node ?
foreach ($xml->gig[0]->attributes() as $Id){
}
thanks
I'm not to familiar with PHP but you could try the following, using an XPath query:
foreach ($xml->xpath("//gig[last()]")[0]->attributes() as $Id){
}
To get to the last gig node, as Frank Bollack noted, we could use XPath.
foreach (current($xml->xpath('/*/gig[last()]'))->attributes() as $attr) {
}
Or a little more verbose but nicer:
$attrs = array();
$nodes = $xml->xpath('/*/gig[last()]');
if (is_array($nodes) && ! empty($nodes)) {
foreach ($nodes[0]->attributes() as $attr) {
$attrs[$attr->getName()] = (string) $attr;
}
}
var_dump($attrs);
It's true that you could use XPath to get the last node (be it a <gig/> node or otherwise) but you can also mirror the same technique you used for the first node. This way:
// first <gig/>
$xml->gig[0]
// last <gig/>
$xml->gig[count($xml->gig) - 1]
Edit: I've just realized, are you simply trying to get the #id attribute of the first and the last <gig/> node? In which case, forget about attributes() and use SimpleXML's notation instead: attributes are accessed as if they were array keys.
$first_id = $xml->gig[0]['id'];
$last_id = $xml->gig[count($xml->gig) - 1]['id'];
I think that this xpath expression should work
$xml->xpath('root/child[last()]');
That should retrieve the last child element that is a child of the root element.
Related
I want to replace a foreach loop using a xpath expression, but I need that a DOMXPath object to return more than one list.
I have the following XML (simplified) and I using DOMDocument and DOMXPath to iterate over it:
<a:RoomsType>
<a:Rooms>
<a:Room>
<a:RPH>0</a:RPH>
</a:Room>
<a:Room>
<a:RPH>1</a:RPH>
</a:Room>
<a:Room>
<a:RPH>2</a:RPH>
</a:Room>
<a:Room>
<a:RPH>0</a:RPH>
</a:Room>
<a:Rooms>
<a:RoomsType>
I want to split the rooms by the RPH number, creating a list of rooms for each RPH number. Currently, I'm using the following code:
//$xpath is a DOMXPath object
$roomsToIterate = $this->xpath->query("//a:RoomsType/a:Rooms/a:Room");
$roomList = array();
foreach ($roomsToIterate as $room) {
$rphCandidate = $room->getElementsByTagName("RPH")->item(0)->nodeValue;
if (!isset($roomList[$rphCandidate])) {
$roomList[$rphCandidate] = array();
}
$roomList[$rphCandidate][] = $room;
}
This is working for now, but I want to replace the foreach loop with a Xpath expression. I can use the expression $rooms = $this->xpath->query("//a:RoomsType/a:Rooms/a:Room[a:RPH='{$rph}']"); with $rph being a number, but how can I do it if I don't know the RPH (it could be anything between 0 and 99). Is it possible?
In short, Are there any way to replace my foreach loop using XPath?
I was thinking about the use of registerPhpFunctions and a custom function, but I concerned about the performance of this approach compared with foreach loop
Xpath 1.0 expression will return a list of nodes, they can to some extend flatten an existing structure if you use an axis like descendant or ancestor, but it will be a list of nodes. It can not group or aggregate them.
You could fetch a lists of nodes with a specific RPH value. But you would need to this for each value, the result would be another loop. This would mean to fetch all RPH values, make them unique, iterate them and execute and Xpath expression for each value.
Your current solution is fine.
For a website i'm making i need to get data from an external XML file.
I load the data like this:
$doc = new DOMDocument();
$url = 'http://myurl/results/xml/12345';
if (!$doc->load($url))
{
echo json_encode(array('error'=> 'error'));
exit;
}
$xpath = new DOMXPath($doc);
$program_date = $xpath->query('//game/date');
Then i use a foreach loop to get all the data
if($program_date){
foreach($program_date as $node){
$programArray['program_date'][] = $node->nodeValue;
}
}
The problem i'm having is that sometimes a certain game doesn't have a date.
So when a game doesn't have a date, i just want it to put "-", instead of the date from the XML file. My problem is that i don't know how to check if a date is present in the data.
I used a lot of ways like isset, !isset, else, !empty, empty
$teamArray['program_kind'][] = "-";
but noting works...
Can someone help me with this problem?
Thanks in advance
You need to iterate the game elements, use them as a context and fetch the data with additional XPath expressions.
But one thing first. Use DOMXPath::evaluate(). DOMXPath::query() only supports location paths. It can only return a node list. But XPath expressions can return scalar values, too.
$xpath = new DOMXPath($doc);
$games = $xpath->evaluate('//game');
The result of //game will always be a DOMNodeList object. It can be an empty list, but you can directly iterate it. A condition like if ($games) will always be true.
foreach ($games as $game) {
Now that you have the game element node, you can use it as an context to fetch other data.
$date = $xpath->evaluate('string(date)', $game);
string() casts the first node of the location path into a string. If it can not match a node, it will return an empty string. Check normalize-space() if you want to remove whitespaces at the same time.
You can validate if the game element has a date node using count().
$hasDate = $xpath->evaluate('count(date) > 0', $game);
The result of this XPath expression is always a boolean.
I have a dom element with html inside chat contains some html elements I'd like to remove, while still keeping some tags that are ok.
I try to iterate through child elements all child elements and delete those that need to be removed
foreach ($node->getElementsByTagName('*') as $element)
if ($element->nodeName != 'br')
$node->removeChild($element);
But this throws a Not Found Error exception which not being caught causes a fatal error.
How would I solve this problem ?
Use the following instead to remove the node:
$element->parentNode->removeChild($element);
getElementsByTagName('*') finds all descendent elements, not child elements. So some of the $element you want to remove are not children of $node, hence the failure.
I'm not 100% sure what your intention is here, but most likely you just want to remove certain immediate children. In this case, do the following:
$nodestoremove = array();
foreach ($node->childNodes as $n) {
if ($n->nodeType===XML_ELEMENT_NODE and $n->nodeName!=='br') {
$nodestoremove[] = $n;
}
}
foreach ($nodestoremove as $n) {
$node->removeChild($n);
}
unset($nodestoremove); // so nodes can be garbage-collected
echo $node->C14N(); // xml fragment after removal
Note that we make two passes: one to identify the nodes to delete, and a second pass to delete. This is because childNodes is an active list, so we can't iterate through it forwards as we delete. (Although we could iterate through it backwards.)
So I have a HTML string like this:
<td class="name">
Some Name
</td>
<td class="name">
Some Name2
</td>
Using XPath I'm able to get value of href attribute using this Xpath query:
$domXpath = new \DOMXPath($this->domPage);
$hrefs = $domXpath->query("//td[#class='name']/a/#href");
foreach($hrefs as $href) {...}
And It's even easier to get a text value, like this:
// Xpath auto. strips any html tags so we are
// left with clean text value of a element
$domXpath = new \DOMXPath($this->domPage);
$names = $domXpath->query("//td[#class='name']/");
foreach($names as $name) {...}
Now I'm curious to know, how can I combine those two queries to get both values with only one query (If it's something like that even posible?).
Fetch
//td[#class='name']/a
and then pluck the text with nodeValue and the attribute with getAttribute('href').
Apart from that, you can combine Xpath queries with the Union Operator | so you can use
//td[#class='name']/a/#href|//td[#class='name']
as well.
To reduce the code to a single loop, try:
$anchors = $domXpath->query("//td[#class='name']/a");
foreach($anchors as $a)
{
print $a->nodeValue." - ".$a->getAttribute("href")."<br/>";
}
As per above :) Too slow ..
Simplest way, evaluate is for this task!
The simplest way to obtain a value is by evaluate() method:
$xp = new DOMXPath($dom);
$v = $xp->evaluate("string(/etc[1]/#stringValue)");
Note: important to limit XPath returns to 1 item (the first a in this case), and cast the value with string() or round(), etc.
So, in a set of multiple items, using your foreach code,
$names = $domXpath->query("//td[#class='name']/");
foreach($names as $contextNode) {
$text = $domXpath->evaluate("string(./a[1])",$contextNode);
$href = $domXpath->evaluate("string(./a[1]/#href)",$contextNode);
}
PS: this example is only for evaluate's illustration... When the information already exists at the node, use what offers best performance, as methods getAttribute(), saveXML(), etc. and properties as $nodeValue, $textContent, etc. supplied by DOMNode. See #Gordon's answer for this particular problem. The XPath subquery (at context) is good for complex cases — or symplify your code, avoiding to check hasChildNodes() + loop for $childNodes, etc. with no significative gain in performance.
I'm using DOMi ( http://domi.sourceforge.net ) to create XML from arrays.
But I don't know how to create attributes in these XML (in arrays, so these attributes appear in the XML). How can I construct these arrays so I can get some tags with attributes after the convertion?
Thank you!
Looking at the source code, apparently you pass the second argument "attributes" to attachToXml:
public function attachToXml($data, $prefix, &$parentNode = false) {
if(!$parentNode) {
$parentNode = &$this->mainNode;
}
// i don't like how this is done, but i can't see an easy alternative
// that is clean. if the prefix is attributes, instead of creating
// a node, just put all of the data onto the parent node as attributes
if(strtolower($prefix) == 'attributes') {
// set all of the attributes onto the node
foreach($data as $key=>$val)
$parentNode->setAttribute($key, $val);
$node = &$parentNode;
}
//...
}