WebObjects/Web Applications/Development/Tips and Tricks

URL'sEdit

  • wocontext.request().uri() = the URL currently being requested

There are several different URL's associated with your application, all of which can be retrieved from various methods on WOApplication. Here is a quick cheat sheet of them:

Browser IPEdit

 /** Returns the IP address of the client.
    * This should return accurate information whether in direct connect or webserver deployment mode.
    * If performance caching is turned on on OS X server, this method will correctly use pc-remote-addr
    * @return The IP address as a string.
    */
   public static String clientIP(WORequest request) {
       Object ipAddress = request.headerForKey("pc-remote-addr");
       if (ipAddress == null) {
               ipAddress = request.headerForKey("remote_addr");
               if( ipAddress == null ) {
                   ipAddress = request.headerForKey("remote_host");
                   if( ipAddress == null ) {
                       ipAddress = request._remoteAddress();
                       if( ipAddress == null ) {
                           ipAddress = request._originatingAddress();
                           if( ipAddress != null ) ipAddress = ((InetAddress)ipAddress).getHostAddress();
                       }
                   }
               }
       }
       return ipAddress == null ? "<address unknown>" : ipAddress.toString();
   }

NSArrayEdit

It's in the docs, but NSArray's implementation of KeyValueCoding is not really what I was expecting. To get an object at a specific numeric index of an NSArray, you'd use the

objectAtIndex() 

method. So what does

NSArray.valueForKey(String key) 

return?

Well, first read the docs: file:///OSX/Developer/Documentation/WebObjects/Reference/com/webobjects/foundation/NSArray.html#valueForKey(java.lang.String)

It turns out that calling valueForKey on an array is the same as calling valueForKey for each element of that array. So if you have an NSArray of Users, calling valueForKey("email"); will return an NSArray of email addresses. calling valueForKey("documents"); will return an NSArray of NSArrays containing document objects. In hindsight (and from looking at the way WOBuilder handles key paths for arrays) this is kind of obvious. But I think the real lesson here is that it is easy to ignore the docs towards the end of an alphabetical page...

HTML-friendly String TruncatingEdit

 import org.apache.commons.lang.*; //From Apache
 import org.clapper.util.text.*; // From http://www.clapper.org/
 
 public static String stripHTMLTagsAndConcatenate(String htmlString, int numberOfChar) {
   return (StringUtils.substringBeforeLast(StringUtils.abbreviate((HTMLUtil.stripHTMLTags(htmlString)), numberOfChar), " ")) + "...";
 }
Last modified on 11 May 2009, at 21:01