Ruby – How to select nodes by matching text

nokogiriruby

If I have a bunch of elements like:

<p>A paragraph <ul><li>Item 1</li><li>Apple</li><li>Orange</li></ul></p>

Is there a built-in method in Nokogiri that would get me all p elements that contain the text "Apple"? (The example element above would match, for instance).

Best Answer

Nokogiri can do this (now) using jQuery extensions to CSS:

require 'nokogiri'

html = '
<html>
  <body>
    <p>foo</p>
    <p>bar</p>
  </body>
</html>
'

doc = Nokogiri::HTML(html)
doc.at('p:contains("bar")').text.strip
=> "bar"

Related Solutions

Ruby – How to write a switch statement in Ruby

Ruby uses the case expression instead.

case x
when 1..5
  "It's between 1 and 5"
when 6
  "It's 6"
when "foo", "bar"
  "It's either foo or bar"
when String
  "You passed a string"
else
  "You gave me #{x} -- I have no idea what to do with that."
end

Ruby compares the object in the when clause with the object in the case clause using the === operator. For example, 1..5 === x, and not x === 1..5.

This allows for sophisticated when clauses as seen above. Ranges, classes and all sorts of things can be tested for rather than just equality.

Unlike switch statements in many other languages, Ruby’s case does not have fall-through, so there is no need to end each when with a break. You can also specify multiple matches in a single when clause like when "foo", "bar".

Ruby – How to sum array of numbers in Ruby

For ruby >= 2.4 you can use sum:

array.sum

For ruby < 2.4 you can use inject:

array.inject(0, :+)

Note: the 0 base case is needed otherwise nil will be returned on empty arrays:

> [].inject(:+)
nil
> [].inject(0, :+)
0

Best Answer

Related Solutions

Ruby – How to write a switch statement in Ruby

Ruby – How to sum array of numbers in Ruby

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