Is there a way to use the rails match method with a simple string, rather than a regular expression?
I'm trying to match a url as such
sometext.match('http://www.example.com')
The problem is, this is stil getting evaluated as a regular expression, so I have to escape all the special characters for this to work properly, as such:
sometext.match('http:\/\/www.example\.com\?foo=bar')
If there's no way to match just a string, is there a way to escape it automatically for regular expressions?
Thanks!
If you just want to know if a string is part of another, use include?.
sometext.include?("http://www.example.com/")
You could try something like:
sometext =~ %r{http://example.com?foo=bar}
Related
I have a value called "FooBar". I want to replace this text with the quotes to Enr::Rds::FooBar without quotes.
Update:
For example, #question.answer_model gives the value "FooBar" (with the quotes)
I am a newbie and somebody please refer me how would i start to know about regex? What is the best way to practice in online?
Since you want to: a) drop the quotes and b) prepend FooBar with Enr::Rds::, I would suggest you preform exactly what is intended, literally:
'"FooBar"'.delete('"').gsub(/\A/, "Enr::Rds::")
# => "Enr::Rds::FooBar"
I think you are trying to convert a string to a constant. try the following
"Enr::Rds::#{#question.answer_model.gsub('"', '')}".constantize.find(...)
I am getting text from a feed that has alot of characters like:
Insignia™ 2.0 Stereo Computer Speaker System (2-Piece) - Black
4th-Generation Apple® iPod® touch
Is there an easy way to get rid of these, or do I have to anticipate which characters I want to delete and use the delete method to remove them? Also, when I try to remove
&
with
str.delete("&")
It leaves behind "amp;" Is there a better way to delete this type of character? Do I need to re-encode the text?
String#delete is certainly not what you want, as it works on characters, not the string as a whole.
Try
str.gsub /&/, ""
You may also want to try replacing the & with a literal ampersand, such as:
str.gsub /&/, "&"
If this is closer to what you really want, you may get the best results unescaping the HTML string. If so try this:
CGI::unescapeHTML(str)
Details of the unescapeHTML method are here.
If you are getting data from a 'feed', aka RSS XML, then you should be using an XML parser like Nokogiri to process the XML. This will automatically unescape HTML entities and allow you to get the proper string representation directly.
For removing try to use gsub method, something like this:
text = "foo&bar"
text.gsub /\b&\b/, "" #=> foobar
I'm building an app in Rails 3 and I need a method to extract all urls from a string and store them in a hash or something. I know I need to use regular expressions but I don't know where exactly to begin with them.
Also, I know about auto_link, but it doesn't quite do what I'm trying to achieve. I just simply need a hash of all the url's from a string.
Thanks!
From http://www.regular-expressions.info/ruby.html
"To collect all regex matches in a string into an array, pass the regexp object to the string's scan() method, e.g.: myarray = mystring.scan(/regex/)."
So you probably need strings that start with "http". So check the docs for that :)
I don't program in Ruby and I'm not very good with regex but maybe this will help you out:
http://www.ozzu.com/programming-forum/url-regex-t104809.html
I'm trying to store regexes in a database but they're not working when used in a .sub(), even though the same regex works when used directly in .sub() as a string.
regex = Class.object.field // Class.object is an active record containing "\w*\s\/\s"
mystring = "first / second"
mystring.sub(/#{regex}/, '')
// => nil
mystring.sub(/\w*\s\/\s/, '')
// => second
Any insight appreciated!
Thanks,
Matt.
Editing to correct class/object terminology (thanks) & correcting my 2nd example as I had shown #{} wrapped around the working regex (cut & paste SNAFU).
To answer your question: It is not quite what kind of thing your Class.object is. If it's an ActiveRecord, it won't work.
Edit: You obviously found that the problem is Rails escaping the regexp.
An ActiveRecord cannot "contain" your regular expression directly; the regexp will be in one of the fields of your record. In which case you'd want to do something like regexp = Class.object.field_containing_the_regexp.
Even if that is not the case, I suspect that the problem is that your regexp is something other than a string. You can quickly test this by using
puts "My regexp: #{regexp}"
The string that you will see in the output will be the one that is used for the regexp.
A String is not a Regexp. You have to create a Regexp object first.
regex = Regexp.new("\w*\s\/\s")
Turns out my regexp didn't cater for all cases - \w didn't account for symbols. After checking in rails console, and seeing the screwey escaping I was alreasdy half-way down the wrong track.
Thanks for the help.
i have a string that maybe contains text with links.
I use these instructions for elaborate it:
message = message.gsub(/http[s]?:\/\/[^\s]+/) do |m|
replace_url(m)
end
if the string is "http://www.youtube.com/watch?v=6zToqLlM8ms&playnext_from=TL&videos=qpCvM5Ocr3M&feature=sub"
the instructions works.
but if the string is "hi my video is http://www.youtube.com/watch?v=6zToqLlM8ms&playnext_from=TL&videos=qpCvM5Ocr3M&feature=sub"
doesn't works
why?
how can i do?
thanks
Beucase this not match a pattern. Get before url add expression to catch some crap before url.
You can also try match a regex pattern to every word. Because url is always one word separated word.