Help with a regex

Rails
1

I’m trying to find a block of text within 

 text
tags, and
replace it with nothing. However, I’m not experienced with regular
expressions. Here’s what I want to do.

s = “Here are some words. 

 this is a code snippet
More
words.”
s.gsub([regex_goes_here],’’)

Now, s becomes:

$: s
=> “Here are some words. More words.”

I just don’t know the regular expression for this. Is it something
like…

s.gsub(/^[:

:][:
:]$, ‘’)

???

That doesn’t seem to work. Any help on this? Thanks in advance.

2

gsub(/

.*</pre>/, “
”)

            


            

              
              
              
            


            

                
                
              


          

          

            

              

              


              
                  
                  
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Shouldn’t the second argument be single quote followed by another single

quote to remove the text between the tags as well as the tags?

            


            

              
              
              
            


            

                
                
              


          

          

            

              

              


              
                  
                  
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Bala P. wrote:




Shouldn’t the second argument be single quote followed by another single

quote to remove the text between the tags as well as the tags?




That’s exactly what I was thinking.  I have padding in the CSS on my

“pre” tags, so if there isn’t any text there, I don’t want a block

element showing.


But that wasn’t the part I asked about - and it’s easy enough to just

switch it out and see if that works.  The hard part was the regex part,

which I really appreciate.  Regular expressions are always so easy once

I see it, but can be complicated when I’m trying to write one.


Thanks again for the help…

            


            

              
              
              
            


            

                
                
              


          

          

            

              

              


              
                  
                  
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Ryan, here is the Ruby mailing list:


ruby-talk-google

[email protected]


http://groups.google.com/group/ruby-talk-google


For Ruby related questions, you will find this group very helpful.

            


            

              
              
              
            


            

                
                
              


          

          

            

              

              


              
                  
                  
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So, maybe I’m doing something wrong, but this isn’t working:


gsub(/
.*</pre>/, “
”)

Here’s what I have:


#application_helper.rb

def strip_pre_block(text)

text.gsub(/
.*</pre>/, ‘’)

text

end

#view

<%= strip_pre_block(to_html(p.body)) %>


The to_html converts the textile text into html.


See anything wrong with this regex?

            


            

              
              
              
            


            

                
                
              


          

          

            

              

              


              
                  
                  
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yes. You’re gsubbing the text, but not doing anything with it. Then

you’re returning your original text. Take that last statement out of

your method, then it will return the results of the gsub.

            


            

              
              
              
            


            

                
                
              


          

          

            

              

              


              
                  
                  
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I don’t think anyone mentioned that the regex will not work if you have

more than one 
 block in the text. In other words, it will fail in

this case:

str = “
DeleteMe
SaveMe
DeleteMe
”

Because the .* is greedy, it’ll get rid of the entire string, including

the SaveMe part. If you KNOW there won’t be any HTML tags inbetween the


 tags, you can do the following:

def strip_pre_block(text)

text.gsub(/
[^<]*</pre>/,’’)

end

HTML is difficult to parse correctly using Regular Expressions.

Ordinarily I would recommend using a real HTML parser, but in your

case, you may be able to use the amended regex above, or even process

the textile before you convert it to HTML.

            


            

              
              
              
            


            

                
                
              


          

          

            

              

              


              
                  
                  
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Thank you - the regex you gave me worked like a charm.