Replace sequential repeating tags with one of that tag in Ruby_问答_开发者

Replace sequential repeating tags with one of that tag in Ruby

开发者 https://www.devze.com 2023-02-12 07:29 出处：网络

I\'m trying to replace multiple sequential tags with just one tag using Ruby. For instance:

相关专题：regex ruby

I'm trying to replace multiple sequential   tags with just one   tag using Ruby.

For instance:

Hello
<br><br/><br>
World!

would become

Hello
<br>开发者_StackOverflow社区
World!

You could do this with a regular expression, like:

 "Hello\n<br><br/><br>\nworld".gsub(/(?im)(<br\s*\/?>\s*)+/,'<br>')

To explain that: the (?im) part has options indicating that the match should be case-insensitive and that . should match newlines. The grouped expression (<br\s*\/?>\s*) matches   (optionally with whitespace and a trailing /) possibly followed by whitespace, and the + says to match one or more of that group.

However, I should point out that in general it's not a good idea to use regular expressions for manipulating HTML - you should use a proper parser instead. For example, here's a better way of doing it using Nokogiri:

require 'nokogiri'

document = Nokogiri::HTML.parse("Hello
<br><br/><br>
World!")

document.search('//br').each do |node|
    node.remove if node.next.name == 'br'
end

puts document

That will produce output like:

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd">
<html><body><p>Hello
<br>
World!</p></body></html>

(The parser turns your input into a well-formed document, which is why you have the DOCTYPE and enclosing <html><body> tags.)