CODEWITHSUNDEEP
rubyxpathnokogiri
Zurix
Zurix

Reputation: 45

Get low level xpath from XML with Nokogiri

I'm trying to store in an array all the unique Xpaths of the low level elements in the XML below, but like I'm doing in array a is being stored all the XML, not only the Xpath themselves. The XML has different levels of Xpath. I mean, some child elements only have 2 ancestors and others more than one.

This is the code I have.

require 'nokogiri'
doc = Nokogiri::XML(<<EOT)

<?xml version="1.0" encoding="UTF-8"?>
<items>
    <item>
        <name>Cake</name>
        <ppu>0.55</ppu>
        <batters>
            <batter>Regular</batter>
            <batter>Chocolate</batter>
            <batter>Blueberry</batter>
            <batter>Devil's Food</batter>
        </batters>
        <topping>None</topping>
        <topping>Glazed</topping>
        <topping>Sugar</topping>
        <topping>Powdered Sugar</topping>
        <topping>Chocolate with Sprinkles</topping>
        <topping>Chocolate</topping>
        <topping>Maple</topping>
    </item>
    <item>
        <name>Raised</name>
        <ppu>0.55</ppu>
        <batters>
            <batter>Regular</batter>
        </batters>
        <topping>None</topping>
        <topping>Glazed</topping>
        <topping>Sugar</topping>
        <topping>Chocolate</topping>
        <topping>Maple</topping>
    </item>
</items>
EOT

a = []
a = doc.xpath("//*")

puts a

I'd like to store in array "a" only the unique xpaths as below:

/items/item/name
/items/item/ppu
/items/item/batters/batter
/items/item/topping

Maybe somebody could help me in how to do this.

Thanks for the help.

Upvotes: 0

Views: 311

Answers (1)

Mark Thomas
Mark Thomas

Reputation: 37527

What you want to select is the "leaf" nodes. You can do it like so:

doc.xpath("//*[not(*)]")

This means "select all elements that don't contain elements".

If you want the XPaths, you'll need to call .path on each node. But the paths provided by Nokogiri have explicit positions (e.g. /items/item[2]/topping[4]), so you'll have to apply a regex to remove them, then remove duplicates with uniq:

doc.xpath("//*[not(*)]").map {|leaf| leaf.path.gsub(/\[.*?\]/, '') }.uniq

Output:

/items/item/name
/items/item/ppu
/items/item/batters/batter
/items/item/topping

Upvotes: 2

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