I want to iterate over each selector found that contains a specific class in order to retrieve all elements within the divs. This works until it reaches one item containing an ID.
for selector in response.xpath("//div[#class='product-list-entry']"):
My best try to get around this is the following code:
for selector in response.xpath("//div[not(#id) and #class='product-list-entry']"):
Both versions lead to only retrieving 5 result sets instead of the full list.
How can I simply ignore the one with the id and iterate on all others?
This should extract the content of the specific divs (examples : text of the div, content of a span and text of a p element) :
def parse(self, response):
for selector in response.xpath("//div[#id='product-list']"):
content = selector.xpath(".//div[not(#id)]/text()").extract()
content2= selector.xpath(".//div[not(#id)]/span").extract()
content3= selector.xpath(".//div[not(#id)]/p/text()").extract()
content4= ...
print (content,content2,content3,...)
Related
I have many statements like this in my test.xml file
<House name="bla"><Room id="bla" name="black" ></Room></House>
How do I print all Rooms with name="black". I am using CSS selector but Only House and Room attributes are taken by the selector.
I started with trying to print all name's, doesn't matter House or Room.
nodes = doc.css("name"). But it gives null as the output. So I am not able to proceed.
In CSS you have a syntax for matching elements by an attribute key-val pair:
nodes = doc.css("[name='black']")
For future reference you can also chain attribute selectors
nodes = doc.css(".my-class[name='black'][foo='bar']")
Or omit the val and match any element where the attribute is present:
nodes = doc.css("[name]")
I'm trying to scrape the cell values from an HTML table. Randomly, some of these cells are empty, and I can't guess which ones with any reliability.
Is there a way to fill a default value in for Nokogiri when it comes across an empty cell?
Thanks for any advice you can provide. Here's my code:
def scrape_stats
stats = []
(2002..2012).to_a.each do |year|
url = "website/#{year}"
doc = Nokogiri::HTML(open(url))
rows = doc.at_css("body tbody").text.split(" ")
(rows.count / 25).times do |i| # there are 25 columns per row
stats << rows.shift(25)
end
end
It sounds like you want something like:
doc.search('td:empty').each{|n| n.content = 'default value'}
This would basically involve using the Nokogiri::XML::Node#add_child method (or the shorter version, Nokogiri::XML::Node#<<) to add a new child node containing the text you want to add to the empty cell.
See this question for an example:
How to add child nodes in NodeSet using Nokogiri
I have a webpage whose DOM structure I do not know...but i know the text which i need to find in that particular webpage..so in order to get its xpath what i do is :
doc = Nokogiri::HTML(webpage)
doc.traverse { |node|
if node.text?
if node.content == "my text"
path << node.path
end
end
}
puts path
now suppose i get an output like ::
html/body/div[4]/div[8]/div/div[38]/div/p/text()
so that later on when i access this webpage again i can do this ::
doc.xpath("#{path[0]}")
instead of traversing the whole DOM tree everytime i want the text
I want to do some further processing , for that i need to know which of the element nodes in the above xpath output have attributes associated with them and what are their attribute values. how would i achieve that? the output that i want is
#=> output desired
{ p => p_attr_value , div => div_attr_value , div[38] => div[38]_attr_value.....so on }
I am not facing the problem in searching the nodes where "my text" lies.. I wanted to have the full xpath of "my text" node..thts why i did the whole traversal...now after finding the full xpath i want the attributes associated with the each element node that I came across while getting to the "my text" node
constraints are ::I cant use any of the developer tools available in a web browser
PS :: I am newbie in ruby and nokogiri..
To select all attributes of an element that is selected using the XPath expression someExpr, you need to evaluate a new XPath expression:
someExpr/#*
where someExpr must be substituted with the real XPath expression used to select the particular element.
This selects all attributes of all (we assume that's just one) elements that are selected by the Xpath expression someExpr
For example, if the element we want is selected by:
/a/b/c
then all of its attributes are selected by:
/a/b/c/#*
Given an HTML document, I want to identify all the numbers in the document and add custom tags around the numbers.
Right now, i use the following:
HtmlNodeCollection bodyNode = htmlDoc.DocumentNode.SelectNodes("//body");
MatchCollection numbersColl = Regex.Matches(htmlNode.InnerText, <some regex>);
Once I get the numbersColl, I can traverse through each Match and get the index.
However, I can't change the InnerText since it is read-only.
What I need is that if match.Value = 100 and match.Index=25, I want to replace that 25 with
<span isIdentified='true'> 25 </span>
Any help on this will be greatly appreciated. Currently, since I am not able to modify the inner text, I have to modify the InnerHtml but some element might have 25 in it's innerHtml. That should not be touched. But how do I identify whether the number is within
an html tag i.e. < table border='1' > has 1 in the tag.
Here's what I did to work around the read-only property limitation of the InnerText property of a Text node, just select the Parent node of the Text node and note the index of the Text node in the child node collections of the Parent node. Then just do a ReplaceChild(...).
private void WriteText(HtmlNode node, string text)
{
if (node.ChildNodes.Count > 0)
{
node.ReplaceChild(htmlDocument.CreateTextNode(text), node.ChildNodes.First());
}
else
{
node.AppendChild(htmlDocument.CreateTextNode(text));
}
}
In your case I believe you need to create a new Element node that wraps the text into an HtmlElement and then just use it as a replacement of the Text node.
Or even better, see if you can do something like the answer posted here:
Replacing a HTML div InnerText tag using HTML Agility Pack
creating a textnode does not what it should do in this case:
myParentNode.AppendChild(D.CreateTextNode("<script>alert('a');</script>"));
Console.Write(myParentNode.InnerHtml);
The result should be something like
<script....
but it is a working script task even if i add it as "TEXT" not as html. This causes kind of a security issue for me because the text would be a input from a anonymous user.
I want to extract all the HTML5 data attributes from a tag, just like this jQuery plugin.
For example, given:
<span data-age="50" data-location="London" class="highlight">Joe Bloggs</span>
I want to get a hash like:
{ 'data-age' => '50', 'data-location' => 'London' }
I was originally hoping use a wildcard as part of my CSS selector, e.g.
Nokogiri(html).css('span[#data-*]').size
but it seems that isn't supported.
Option 1: Grab all data elements
If all you need is to list all the page's data elements, here's a one-liner:
Hash[doc.xpath("//span/#*[starts-with(name(), 'data-')]").map{|e| [e.name,e.value]}]
Output:
{"data-age"=>"50", "data-location"=>"London"}
Option 2: Group results by tag
If you want to group your results by tag (perhaps you need to do additional processing on each tag), you can do the following:
tags = []
datasets = "#*[starts-with(name(), 'data-')]"
#If you want any element, replace "span" with "*"
doc.xpath("//span[#{datasets}]").each do |tag|
tags << Hash[tag.xpath(datasets).map{|a| [a.name,a.value]}]
end
Then tags is an array containing key-value hash pairs, grouped by tag.
Option 3: Behavior like the jQuery datasets plugin
If you'd prefer the plugin-like approach, the following will give you a dataset method on every Nokogiri node.
module Nokogiri
module XML
class Node
def dataset
Hash[self.xpath("#*[starts-with(name(), 'data-')]").map{|a| [a.name,a.value]}]
end
end
end
end
Then you can find the dataset for a single element:
doc.at_css("span").dataset
Or get the dataset for a group of elements:
doc.css("span").map(&:dataset)
Example:
The following is the behavior of the dataset method above. Given the following lines in the HTML:
<span data-age="50" data-location="London" class="highlight">Joe Bloggs</span>
<span data-age="40" data-location="Oxford" class="highlight">Jim Foggs</span>
The output would be:
[
{"data-location"=>"London", "data-age"=>"50"},
{"data-location"=>"Oxford", "data-age"=>"40"}
]
You can do this with a bit of xpath:
doc = Nokogiri.HTML(html)
data_attrs = doc.xpath "//span/#*[starts-with(name(), 'data-')]"
This gets all the attributes of span elements that start with 'data-'. (You might want to do this in two steps, first to get all the elements you're interested in, then extract the data attributes from each in turn.
Continuing the example (using the span in your question):
hash = data_attrs.each_with_object({}) do |n, hsh|
hsh[n.name] = n.value
end
puts hash
produces:
{"data-age"=>"50", "data-location"=>"London"}
Try looping through element.attributes while ignoring any attribue that does not start with a data-.
The Node#css docs mention a way to attach a custom psuedo-selector. This might look like the following for selecting nodes with attributes starting with 'data-':
Nokogiri(html).css('span:regex_attrs("^data-.*")', Class.new {
def regex_attrs node_set, regex
node_set.find_all { |node| node.attributes.keys.any? {|k| k =~ /#{regex}/ } }
end
}.new)