I am parsing a 3rd party HTML page using PHP DOMDocument and DomXPath.
I use the following code:
$dom = new DOMDocument();
$html = file_get_contents($url);
$dom->loadHTML('<?xml encoding="UTF-8">' . $html);
$dom->encoding = "UTF-8";
$finder = new DomXPath($dom);
Now there are several elements using the same class, but I want to target the one that uses only the given class, for example:
<table class="tbl"></table>
<table class="tbl red"></table>
<table class="tbl large blue"></table>
I use the following selector:
$classname = "tbl";
$nodes = $finder->query("//*[contains(#class, '$classname')]");
Which, of course fetches all three tables given above. Is there a simple way to get only the first one?
Thanks
Yes, there is a way.
Note that with your XPath query you can access to desired node by this way:
$nodes->item(0);
To select only the first node you have to modify your pattern in this way:
$nodes = $finder->query("(//*[contains(#class, '$classname')])[1]");
But to access to desired node you need anyway to use this syntax:
$nodes->item(0);
Related
I'm calling some wikipedia content two different way:
$html = file_get_contents('https://en.wikipedia.org/wiki/Sans-serif');
The first one is to call the first paragraph
$dom = new DomDocument();
#$dom->loadHTML($html);
$p = $dom->getElementsByTagName('p')->item(0)->nodeValue;
echo $p;
The second one is to call the first paragraph after a specific $id
$dom = new DOMDocument();
#$dom->loadHTML($html);
$p=$dom->getElementById('$id')->getElementsByTagName('p')->item(0);
echo $p->nodeValue;
I'm looking for a third way to call all the first part.
So I was thinking about calling all the <p> before the id or class "toc" which is the id/class of the table of content.
Any idea how to do that?
If you're just looking for the intro in plain text, you can simply use Wikipedia's API:
https://en.wikipedia.org/w/api.php?format=json&action=query&prop=extracts&exintro=&explaintext=&titles=Sans-serif
If you want HTML formatting as well (excluding inner images and the likes):
https://en.wikipedia.org/w/api.php?format=json&action=query&prop=extracts&exintro=&titles=Sans-serif
You could use DOMDocument and DOMXPath with for example an xpath expression like:
//div[#id="toc"]/preceding-sibling::p
$doc = new DOMDocument();
$doc->load("https://en.wikipedia.org/wiki/Sans-serif");
$xpath = new DOMXPath($doc);
$nodes = $xpath->query('//div[#id="toc"]/preceding-sibling::p');
foreach ($nodes as $node) {
echo $node->nodeValue;
}
That would give you the content of the paragraphs preceding the div with id = toc.
I am using domDocument hoping to parse this little html code. I am looking for a specific span tag with a specific id.
<span id="CPHCenter_lblOperandName">Hello world</span>
My code:
$dom = new domDocument;
#$dom->loadHTML($html); // the # is to silence errors and misconfigures of HTML
$dom->preserveWhiteSpace = false;
$nodes = $dom->getElementsByTagName('//span[#id="CPHCenter_lblOperandName"');
foreach($nodes as $node){
echo $node->nodeValue;
}
But For some reason I think something is wrong with either the code or the html (how can I tell?):
When I count nodes with echo count($nodes); the result is always 1
I get nothing outputted in the nodes loop
How can I learn the syntax of these complex queries?
What did I do wrong?
You can use simple getElementById:
$dom->getElementById('CPHCenter_lblOperandName')->nodeValue
or in selector way:
$selector = new DOMXPath($dom);
$list = $selector->query('/html/body//span[#id="CPHCenter_lblOperandName"]');
echo($list->item(0)->nodeValue);
//or
foreach($list as $span) {
$text = $span->nodeValue;
}
Your four part question gets an answer in three parts:
getElementsByTagName does not take an XPath expression, you need to give it a tag name;
Nothing is output because no tag would ever match the tagname you provided (see #1);
It looks like what you want is XPath, which means you need to create an XPath object - see the PHP docs for more;
Also, a better method of controlling the libxml errors is to use libxml_use_internal_errors(true) (rather than the '#' operator, which will also hide other, more legitimate errors). That would leave you with code that looks something like this:
<?php
libxml_use_internal_errors(true);
$dom = new DOMDocument();
$dom->loadHTML($html);
$xpath = new DOMXPath($dom);
foreach($xpath->query("//span[#id='CPHCenter_lblOperandName']") as $node) {
echo $node->textContent;
}
PHP DOM is returning all the nodes even if I am in a specific tag. I have been trying to solve this thing for around 2 weeks now but no progress. Please help.
Here is my code:
$dom = new DOMDocument;
$dom->loadhtmlfile($url);
$doc=$dom->documentElement;
$res = $doc->getElementsByTagName('td')->item(54);
$tables = $res->getElementsByTagName('table'); //Here it returns every 'table', not just the ones which are under that 'td'
From the documentation: getElementsByTagName — Searches for all elements with given local tag name
If you want to find the table inside a 'td' element, use a XPath query.
$xpath = new DOMXpath($dom);
$tables = $xpath->query("//td/table");
I am parsing an HTML page with DOM and XPath in PHP.
I have to fetch a nested <Table...></table> from the HTML.
I have defined a query using FirePath in the browser which is pointing to
html/body/table[2]/tbody/tr/td[2]/table[2]/tbody/tr/td/table
When I run the code it says DOMNodeList is fetched having length 0. My objective is to spout out the queried <Table> as a string. This is an HTML scraping script in PHP.
Below is the function. Please help me how can I extract the required <table>
$pageUrl = "http://www.boc.cn/sourcedb/whpj/enindex.html";
getExchangeRateTable($pageUrl);
function getExchangeRateTable($url){
$htmlTable = "";
$xPathTable = nulll;
$xPathQuery1 = "html/body/table[2]/tbody/tr/td[2]/table[2]/tbody/tr/td/table";
if(strlen($url)==0){die('Argument exception: method call [getExchangeRateTable] expects a string of URL!');}
// initialize objects
$page = tidyit($url);
$dom = new DOMDocument();
$dom->loadHTML($page);
$xpath = new DOMXPath($dom);
// $elements is sppearing as DOMNodeList
$elements = $xpath->query($xPathQuery1);
// print_r($elements);
foreach($elements as $e){
$e->firstChild->nodeValue;
}
}
have you try like this
$dom = new domDocument;
$dom->loadHTML($tes);
$dom->preserveWhiteSpace = false;
$tables = $dom->getElementsByTagName("table");
$rows = $tables->item(0)->getElementsByTagName("tr");
print_r($rows);
Remove the tbody's from your XPath query - they are in most cases inserted by your browser, as is with the page you are trying to scrape.
/html/body/table[2]/tr/td[2]/table[2]/tr/td/table
This will most likely work.
However, its probaly more safe to use a different XPath. Following XPath will select the first th based on it's textual content, then select the tr's parent - a tbody or table:
//th[contains(text(),'Currency Name')]/parent::tr/parent::*
The xpath query should be with a leading / like :-
/html/...
I am loading HTML into DOM and then querying it using XPath in PHP. My current problem is how do I find out how many matches have been made, and once that is ascertained, how do I access them?
I currently have this dirty solution:
$i = 0;
foreach($nodes as $node) {
echo $dom->savexml($nodes->item($i));
$i++;
}
Is there a cleaner solution to find the number of nodes, I have tried count(), but that does not work.
You haven't posted any code related to $nodes so I assume you are using DOMXPath and query(), or at the very least, you have a DOMNodeList.
DOMXPath::query() returns a DOMNodeList, which has a length member. You can access it via (given your code):
$nodes->length
If you just want to know the count, you can also use DOMXPath::evaluate.
Example from PHP Manual:
$doc = new DOMDocument;
$doc->load('book.xml');
$xpath = new DOMXPath($doc);
$tbody = $doc->getElementsByTagName('tbody')->item(0);
// our query is relative to the tbody node
$query = 'count(row/entry[. = "en"])';
$entries = $xpath->evaluate($query, $tbody);
echo "There are $entries english books\n";