dev.enekoalonso.com » freemarker http://dev.enekoalonso.com having fun with code Wed, 12 Oct 2011 21:40:17 +0000 en hourly 1 Equivalent of parseInt() in Freemarker http://dev.enekoalonso.com/2010/07/02/equivalent-of-parseint-in-freemarker/ http://dev.enekoalonso.com/2010/07/02/equivalent-of-parseint-in-freemarker/#comments Fri, 02 Jul 2010 19:05:40 +0000 Eneko Alonso http://dev.enekoalonso.com/?p=604 Programming languages have methods to cast integers to strings and strings to integers, but usually is had to find equivalents to parseInt(), a Javascript function that basically removes all non-numeric characters from a string and returns the resulting integer.

Today, while working on a Freemarker template, I had to convert strings like “40 ms.” and “128 px” to their respective integers 40 and 128. The solution I found is to use regular expressions, which are kind of tricky in Freemarker but can save you lots of time.

Example in Javascript:

  1. console.log(parseInt("40 ms")) // outputs 40
  2. console.log("40 ms".match(/^\d+/)[0]) // outputs 40

Same in Freemarker:

  1. <#assign myInt = "40 ms."?matches("^(\\d+)(.*)")[0]?groups[1]>

Looks like even using regular expressions, in Freemarker we need to match the whole string with groups to separate the number from the rest. Thus, this will work only if the number is at the beginning of the string, which was the initial requirement in my case.

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]]> http://dev.enekoalonso.com/2010/07/02/equivalent-of-parseint-in-freemarker/feed/ 0 Regular expressions in Freemarker http://dev.enekoalonso.com/2009/04/03/regular-expressions-in-freemarker/ http://dev.enekoalonso.com/2009/04/03/regular-expressions-in-freemarker/#comments Fri, 03 Apr 2009 21:49:00 +0000 Eneko Alonso http://dev.enekoalonso.com/?p=293 At work we have our custom CMS (SWITCH) which uses Freemarker to create template-based pages. So far I had never needed this, but today I had to figure out how to strip all html tags from a text block. Well, nothing like a good RegEx for that :)

Trimming an HTML block to 100 characters and stripping all the html tags:

  1. <p class="bio">
  2.   ${Text?replace("</?[^>]+(>|$)", "", "r")?substring(0,100)}…
  3. </p>

RegEx in Freemarker differ a little bit from RegEx in Javascript, so be aware of that :) Freemarker uses Java 1.4 RegEx syntax.

Enjoy!

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