C# Regex appending every 2nd lot?

[master maste]

I'm currently using regex on some of my webpages, and I'm adding the text to a .txt file on my computer.

Regex regexObj = new Regex("(?<=<div class=\"item-artist\" style=\"display:none;\">)(.*?)(?=</div>)|((?<=<div class=\"item-title\" style=\"display:none;\">)(.*?)(?=</div>))");

I'm currently appending

textBox.AppendText(matchResults.Value + " - \r\n");

Everything up to here works perfectly; I'm wondering how to only add the appended text to every 2nd lot.

I want to display the artist with a dash and then the title.

Artist - Title
Artist - Title
Artist - Title
Artist - Title

^^Like that, at the moment it does this.

Artist - Title - Artist - Title - Artist - Title - Artist - Title

Thanks for any help you may be able to give, I've been googling all night.

 

[Samuraid]

What does your input/source data look like?

 

[master maste]

Looks like this:

<div class="item-title" style="display: none;">TitleIWant</div>

<div class="item-artist" style="display: none;">ArtistIWant</div>

 

[Icyculyr]

Can you post your full code so I can have a look at it better?

textBox.AppendText(matchResults.Value + " - \r\n");

I assume this is in some kind of a loop, why can't you just use an int to count every second value and append the text differently? or have I misunderstood?

I don't remember the C# syntax that well (I use VB), however I'd do something like this:

int i = 0;
(in your loop)
if (i % 2 == 0)
{
    //Display result with -
}
else
{
    //Display result without -
}
i += 1;

iirc % is the modulo symbol, I'd have to see more of your code to give a more detailed reply.

 

[Vestras]

% is indeed modulo.

 

[master maste]

Thanks for the help guys, this has been great.

I'm having some more regex issues, and I might as well put them here instead of creating another thread for the same thing.

I'm trying to pull the text from between <TITLE></TITLE> tags. I'm currently using:

Regex regexObj = new Regex("(?<=<TITLE>)(.*)(?=</TITLE>)");

I've tried various combinations, searched google, read tutorials etc but its not finding anything. I can however find <TITLE> and </TITLE> separately...

I'm currently working on the page through my localhost and looking at the sites html code it should show this:

<TITLE>
      
        
        
        
        
          Excellent Monitor: Viewsonic VX2433WM
        
      
      
    </TITLE>

Thats the exact formatting with all the spaces etc.(maybe the weird gapping is causing my issue?)

anyways +rep for the last bit of help

 

[Vestras]

Ehh, don't know what regex system you're using but to me that regex looks kind of wrong and basically could go wrong if the input was <title></title> I would find some way to check for <title> even though it was capitalized.

This is how I'd do it:
\<title\>\s*(?<input>.+)\s*\</title\>

Then, if you're using C#, do this:

Match match = Regex.Match(inputString, pattern);
// To access the input group:
string input = match.Groups["input"].Value;

Another time just test your regexes with a program called RegexBuddy, it's very good.

 

[master maste]

Maybe it looks wrong because its not working?

Also I'm trying to exclude the <TITLE></TITLE> tags and just get whats in between them. - I understand thats what your "input" group was for, but I'm using look arounds so thats not really necessary

Hmm messing around with your one but c# does not recognize the escape sequence \s...

edit: oh yeah thanks for RegexBuddy, just downloaded it and going to mess around with it tonight and see if I can get something.

edit2:Ok heres what I've got so far (note this works perfectly in RegexBuddy, but not properly in c# even though the same html code is being used.):

Regex regexObj = new Regex("<(title)>(.*?)<(/title)>");
                Match matchResults = regexObj.Match(WebScreen);
                while (matchResults.Success)
                {
                    display.AppendText(matchResults.Value + "\r\n");
                    matchResults = matchResults.NextMatch();
                }

c# will only pick up the title when the regex code is as follows:

Regex regexObj = new Regex("<(title)>");

For some reason it wont let me add the closing title tag or anything in between, but I can do all 3 separately...

 

[Vestras]

Your code is wrong. It should be this:

Regex regexObj = new Regex(@"<(title)>(.*?)<(/title)>");
                Match matchResults = regexObj.Match(WebScreen);
                while (matchResults.Success)
                {
                    display.AppendText(matchResults.Value + "\r\n");
                    matchResults = matchResults.NextMatch();
                }

 

[master maste]

Yea that still didn't show up anything... hmmm gonna try some things and post back.

 

[Vestras]

Can you elabroate on what the problem is now?

 

[Icyculyr]

I found this on another forum, it's in VB because I don't know how to do Singleline + IgnoreCase in C#:

Dim rRegex As New Regex("(?<=<title>).+?(?=</title>)", RegexOptions.Singleline Or RegexOptions.IgnoreCase)

I had to manually remove the NewLine character from it to get rid of the weird symbols, not sure what the equiv. is in C# but I used this in VB:

Dim sValue As String = mMatch.Value.Replace(ControlChars.NewLine, "")

I'm not sure if you have ControlChars, maybe try Environment.NewLine if you have that or whatever represents NewLine in C#.

 

[master maste]

Thanks that worked a charm, turns out I needed to add the RexgexOptions.Singleline

Code:

Regex regexObj = new Regex(@"<(TITLE)>(.*?)<(/TITLE)>", RegexOptions.Singleline);

Thank you guys for your help.

edit: although it works I'm currently trying to figure out how to get rid of the extra spaces before and after the title tags. Don't know why it was formatted like that, not sure how to do it without getting rid of the spaces in between the title words themselves.

edit2: just realized that I don't really need to know how to get rid of the extra spaces, but knowing wouldn't hurt if anyone knew..

 

[Icyculyr]

I'd loop from the start of the line until you find the first letter to remove the spaces at the front, for the end it may be a bit more tricky, but try and find the last "letter" by checking say 10-20 spaces ahead if they are all spaces then you can probably remove them (it's unlikely there would be 20 spaces between any word or letter)

 

[master maste]

just thinking I could potentially not append anything that has 2 spaces next to each other right? since words won't have more than 1 space in between...

 

[Vestras]

You can do: string nospacesString = firstString.Trim();

 

[Icyculyr]

just thinking I could potentially not append anything that has 2 spaces next to each other right? since words won't have more than 1 space in between...

Technically yes.

 

[master maste]

argghh just did some testing and figured out that c# is using the websites source code and not whats actually on the website, I believe most of it is done via JS.

Makes sense why most of the other tags I tried pulled nothing what so ever since I was running from what was actually on the page elements...

Anyway to make it use whats on the page instead of the source code before it actually uses the javascript?

Must be a way somehow... Thanks for all the help so far anyways .

 

[Icyculyr]

Erm could you turn javascript off on your browser? how are you getting the page contents of the website?

 

[master maste]

using Firefox, right clicking on page "view page source". But clearly C# is getting the actual source.

edit: I could turn javascript off, but there are error messages displayed on the page when you dont have javascript enabled...