[xwiki-devs] [VOTE] New RegexTool velocity tool - xwiki-devs@xwiki.org

15 Sep 2009

Hi,

I'm working on http://jira.xwiki.org/jira/browse/XWIKI-4345 and in  
order to implement the logic in contenview.vm I need to perform some  
regex find() from velocity.
I'd like to propose introducing a new velocity tool for this:

#-#   velocity.tools = regextool = org.xwiki.velocity.tools.RegexTool

Right now RegexTool has one method:

     /**
      * @param content the content to parse
      * @param regex the regex to look for in the passed content
      * @return empty list if the passed regex doesn't match the  
content or several {@link RegexResult} objects
      *         containing the matched position and matched content  
for all capturing groups, the first group
      *         representing the whole . The first object is  
represents the entier pattern
      */
     public List<RegexResult> find(String content, String regex)
     {
         List<RegexResult> result = new ArrayList<RegexResult>();
         Matcher matcher = Pattern.compile(regex,  
Pattern.MULTILINE).matcher(content);
         if (matcher.find()) {
             for (int i = 0; i < matcher.groupCount() + 1; i++) {
                 result.add(new RegexResult(matcher.start(i),  
matcher.end(i), matcher.group(i)));
             }
         }
         return result;
     }

WDYT?

FYI here's what I currently have in contenview.vm:

##  
----------------------------------------------------------------------------
## Remove the first rendered H1 or H2 if the following conditions are  
met:
## - the document's title is set
## - the title compatibility flag is on
## - the title extracted from the rendered content is the same as the  
set title
## We need to do this since we've changed how titles are used and we  
need to
## ensure we don't break existing documents that have not yet migrated  
to the
## new way.
##  
-----------------------------------------------------------------------------
#set ($titleToDisplay = $tdoc.displayTitle)
#if ($cdoc.title && $cdoc.title.length() > 0)
   ## Look for first H1 or H2 either in lowercase or uppercase
   #set ($regexResult = $regextool.find($renderedContent, "<[hH][12].*? 
...
 <span>(.*)</span></[hH][12]>"))
   #if (!$regexResult.isEmpty() &&  
$regexResult.get(1).group.equals($titleToDisplay))
     #if ($regexResult.get(0).end <  
$mathtool.sub($renderedContent.length(), 1))
       #set ($renderedContent = "${renderedContent.substring(0,  
$regexResult.get(0).start)}$ 
{renderedContent.substring($regexResult.get(0).end)}")
     #else
       #set ($renderedContent = $renderedContent.substring(0,  
$regexResult.get(0).start))
     #end
   #end
#end

Note that the other option is to introduce yet another API in Document  
for this but it doesn't look right to me.

Here's my +1

Thanks
-Vincent