How can I scrape the string from this tag in ruby - css

Question

I'm currently trying to do my first proper project outside of Codecademy/Baserails and could use some pointers. I'm using a scraper as part of one of the Baserails projects as a base to work from. My aim is to get the string "Palms Trax" and store it in array called DJ. I also wish to get the string "Solid Steel Radio Show" and store it in an array called source. My plan was to extract all the lines from the details section into a subarray and to then filter it into the DJ and Source arrays but if there is a better way of doing it please tell me. I've been trying various different combinations such as '.details none.li.div', 'ul details none.li.div.a' etc but can't seem to stumble on the right one. Also could someone please explain to me why the code
page.css('ol').each do |line|
subarray = line.text.strip.split(" - ")
end
only works if I declare the subarray earlier outside of the loop as in the Baserails project I am working from this did not seem to be the case.
Here is the relevant html:
<!-- Infos -->
<ul class="details none">
<li><span>Source</span><div> Solid Steel Radio Show</div></li>
<li><span>Date</span><div>2015.02.27</div></li>
<li><span>Artist</span><div>Palms Trax</div></li>
<li><span>Genres</span><div>Deep HouseExperimentalHouseMinimalTechno</div></li>
<li><span>Categories</span><div>Radio ShowsSolid Steel Radio Show</div></li>
<li><span>File Size</span><div> 135 MB</div></li>
<li><span>File Format</span><div> MP3 Stereo 44kHz 320Kbps</div></li>
</ul>
and my code so far:
require "open-uri"
require "nokogiri"
require "csv"
#store url to be scraped
url = "http://www.electronic-battle-weapons.com/mix/solid-steel-palms-trax/"
#parse the page
page = Nokogiri::HTML(open(url))
#initalize empty arrays
details = []
dj = []
source = []
artist = []
track = []
subarray =[]
#store data in arrays
page.css('ul details none.li.div').each do |line|
details = line.text.strip
end
puts details
page.css('ol').each do |line|
subarray = line.text.strip.split(" - ")
end

Answer 1

I'm Alex, one of the co-founders of BaseRails. Glad you're now starting to work on your own projects - that's the best way to start applying what you've learned. I thought I'd chip in and see if I can help out.
I'd try this:
page.css(ul.details.none li div a)
This will grab each of the <a> tags, and you'll be able to use .text to extract the text of the link (e.g. Solid Steel Radio Show, Palms Trax, etc). To understand the code above, remember that the . means "with a class called..." and a space means "that has the following nested inside".
So in English, "ul.details.none li div a" is translated to become "a <ul> tag with a class called "details" and another class called "none" that has an <li> tag nested inside, with a <div> tag nested inside that, with an <a> tag inside that. Try that out and see if you can then figure out how to filter the results into DJ, Source, etc.
Finally, I'm not sure why your subarray needs to be declared. It shouldn't need to be declared if that's the only context in which you're using it. FYI the reason why we don't need to declare it in the BaseRails course is because the .split function returns an array by default. It's unlike our name, price, and details arrays where we're using a different function (<<). The << function can be used in multiple contexts, so it's important that we make clear that we're using it to add elements to an array.
Hope that helps!