Extract attribute value from html element

Question

Been struggling with this for a couple of hours now...

I have the following regex:

(?<=\bdata-video-id=""."">)(.*?)(title=.*?>)

The following input:

         <div class="cameras">            
            <table class="results">
                <colgroup>
                    <col class="col0">
                    <col class="col1">
                </colgroup>
                <thead>
                    <tr>
                        <th title="Name">
                            Name
                        </th>
                        <th title="Date">
                            Date
                        </th>
                    </tr>
                </thead>
                <tbody>
                    <tr data-video-id="1">
                        <td title="149 - Cam123">
                            149 - Cam123
                        </td>
                        <td title="Feb 18 2013">
                            Feb 18 2013
                        </td>
                    </tr>
                    <tr data-video-id="2">
                        <td title="150 - Cam456">
                            150 - Cam456
                        </td>
                        <td title="Feb 18 2013">
                            Feb 18 2013
                        </td>
                    </tr>                   
                </tbody>
            </table>
        </div>

The regex outputs this:

<td title="149 - Cam123">
<td title="150 - Cam456">

But what I'd like to get is the contents of the title attribute of the 1st cell from every table row:

149 - Cam123
150 - Cam456

The number of rows may obviously vary but the number of columns is fixed. Please help me fine tune the above regex. Thanks

NOTE: The solution MUST be a regular expression. I do not have access to the code base therefore an HTML parser or any other kind of code intervention is not possible. The only way I can hook into the application is by injecting a different regex.

**[obligatory ͠P̯͍̭O̚N̐Y̡ link](http://stackoverflow.com/a/1732454/664108)** — Fabian Schmengler, Feb 20 '13 at 16:01
I found a rule, any regex + xml/html codes questions would be commented/answered with "why not a parser" yes, if parsing the whole xml/html document, regex won't be the right choice. however, in many cases, our program reading a **part** of text, which are some html/xml elements in certain format. in this case, regex does work. Also works for very simple xml/html structure with fixed format case. or we have to import a new library and write dozen lines codes just for getting an attribute. well my 2 cents... — Kent, Feb 20 '13 at 16:07

score 0 · Accepted Answer · edited May 23 '17 at 12:18

0

Based on the OP requirements that it MUST be a regex, then my suggestion would be to add a group wrapper to the inner title information:

(?<=\bdata-video-id=""."">).*?title="(.*?)">

Otherwise, the general solution is to not use a regex:

Why are you using a regex? The typical solution for this due to the complexities of the tags is to use an HTML parser

Here is a SO about this topic

Here is another even more popular response on using regex for XHTML which was pointed out by Jeff Atwood in this blogpost

edited May 23 '17 at 12:18

Community

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answered Feb 20 '13 at 15:58

Justin Pihony

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Yep, I know. However this is something running on customer premise and I cannot change the code base. It has some kind of regular expression engine which I can inject regexes into without touching the code base. – Tsef Feb 20 '13 at 16:03
I have updated my answer in that case. Please be careful with this per the links I provided as regex is not suggested here – Justin Pihony Feb 20 '13 at 16:07
hmmm...that didn't do the trick. can you please post the full regex, I'm not too much of a regex guy... – Tsef Feb 20 '13 at 16:18
@zaf As rrrr commented, could you post the input. I think I was going off of the wrong input – Justin Pihony Feb 20 '13 at 17:01
input posted along with a short explanation – Tsef Feb 20 '13 at 19:25

Extract attribute value from html element

1 Answers1