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Abbreviates a String which can contain html tags. Html tags are not counted in String length. It also try to handle open tags and html entities. Adopted from http://www.displaytag.org/1.2/displaytag/apidocs/org/displaytag/util/HtmlTagUtil.html
#*
Abbreviates a String which can contain html tags. Html tags are not counted in String length. It also try to handle open tags and html entities.
Adopted from http://www.displaytag.org/1.2/displaytag/apidocs/org/displaytag/util/HtmlTagUtil.html
@param str full String. null is handled by returning null
@param maxLength maximum number of characters (excluding tags)
@param byNumberOfWords if true maxLength will be the number of words returned, elsewhere will represent the number of characters.
@return abbreviated String
*#
#macro (abbreviateHtmlString $str, $maxLength, $byNumberOfWords)
#if ($str == "" || $str.length() <= $maxLength )
$str
#else
#set ($sz = $str.length())
#set ($szMinusOne = $sz - 1)
#set ($newStr = "")
#set ($inTag = false)
#set ($inTagName = false)
#set ($endingTag = false)
#set ($count = 0)
#set ($chopped = false)
#set ($choppedPos = 0)
#set ($entityChars = 0)
#set ($currentTag = "")
#set ($openTags = [])
#foreach ($i in [0..$szMinusOne])
#if ($count >= $maxLength)
#set ($chopped = true)
#set ($choppedPos = $i)
#break
#end
#set ($c = $str.charAt($i))
#if ($c == "<")
#set ($inTag = true)
#set ($inTagName = true)
#elseif ($inTag)
#if ($inTagName && $c == "/")
#if ($currentTag.length() == 0)
## Ending tag found
#set ($endingTag = true)
#else
## Empty tag, reset and don't save
#set ($inTagName = false)
#end
#set ($currentTag = "")
#elseif ($inTagName && ($c == " " || $c == ">"))
#set ($inTagName = false)
#if (!$endingTag)
#set ($_void = $openTags.add(0, $currentTag))
#else
#set ($_void = $openTags.remove($currentTag))
#end
#set ($currentTag = "")
#set ($endingTag = false)
#if ($c == ">")
#set ($inTag = false)
#end
#elseif ($c == ">")
#set ($inTag = false)
#elseif ($inTagName)
#set ($currentTag = "${currentTag}${c}")
#end
#else
#if ($byNumberOfWords)
#if ($c.matches("\s"))
#set ($count = $count + 1)
#end
#else
## Handle entities
#if ($c == "&")
#set ($entityChars = 1)
#elseif ($entityChars == 0)
#set ($count = $count + 1)
#else
## End entity
#if ($entityChars > 0 && $c == ";")
#set ($entityChars = 0)
#set ($count = $count + 1)
#else
#set ($entityChars = $entityChars + 1)
#end
## Assume an unescaped & if entity doesn't close after max 5 chars
#if ($entityChars > 5)
#set ($count = $count + $entityChars)
#set ($entityChars = 0)
#end
#end
#end
#end
#if ($inTag || (!$byNumberOfWords || $count < $maxLength))
#set ($newStr = "${newStr}${c}")
#end
#end
#if ($chopped)
#set ($newStr = "${newStr}...")
#end
#if ($openTags.size() > 0)
## Quickly fixes closed tags
#set ($remainingToken = $str.substring($choppedPos))
#set ($openTagsSize = $openTags.size())
#set ($openTagsSizeMinusOne = $openTagsSize - 1)
#foreach ($j in [0..$openTagsSizeMinusOne])
#set ($closingTag = $openTags.get($j))
#set ($closingTag = "</${closingTag}>")
## We only add closing tags that exists in the original String, so we don't have to understand
## html/xhtml differences and keep a list of html unclosed tags
#if ($remainingToken.indexOf($closingTag) > -1)
#set ($newStr = "${newStr}${closingTag}")
#end
#end
#end
$newStr
#end
#end
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