Grails external logging

Grails has some fantastic built-in facilities for logging. If you haven’t see them already, you should check them out.

There is only one problem: what happens if you want to configure your logging outside of Grails at the app server layer? Grails is only one of the apps in our stack, so we prefer to control our logging configuration at the app server JVM layer. Looking at the Grails user guide’s logging section, there is seemingly no clear way of doing this. But if you know one thing about Grails, you know that you can do anything with it. You just have to do some digging. After you do, you’ll find out that Grails is using an app context listener plugin to wrap and control logging in a WAR deployment: org.codehaus.groovy.grails.plugins.log4j.web.util.Log4jConfigListener . This is configured inside the web.xml that is deployed with the app, so you need to modify it before deployment. There are two ways to do this. You can run 

grails install-templates

and edit out the Log4j listener element from src/templates/war/web.xml:

<listener>
   <listener-class>org.codehaus.groovy.grails.plugins.log4j.web.util.Log4jConfigListener</listener-class>
</listener>

Alternatively, you can create a file scripts/_Events.groovy under your app with these contents:

// Add this code to scripts/_Events.groovy under your Grails app
// Removes Log4jConfigListener from Grails web.xml

import groovy.xml.DOMBuilder
import groovy.xml.XmlUtil
import groovy.xml.dom.DOMCategory

eventCreateWarStart = { warName, stagingDir ->

   def webXmlFile = new File(stagingDir, '/WEB-INF/web.xml') 
   def wxml = DOMBuilder.parse(new StringReader(webXmlFile.text)).documentElement

   String className = 'org.codehaus.groovy.grails.plugins.log4j.web.util.Log4jConfigListener'
   use (DOMCategory) {
      def listenerNodes = wxml.'listener'
      for (n in listenerNodes) {
         if (n.'listener-class'.text() == className) {
            wxml.removeChild n
         }
      }
   }

   webXmlFile.withWriter { it << XmlUtil.serialize(wxml) }
}

That’s it!


UTF-8 all the way

Recently we have been tracking the various integration points in the Traackr technology stack and making sure we are 100% UTF-8 compliant all the way thru. Each layer has it’s own set up and required configuration. Sometimes right out of the box, sometimes with more tweaking. 

Ran into this article while doing some research, that shows how to make your web app UTF-8 enabled. A lot of configuration for something seemingly simple.

http://www.itnewb.com/tutorial/UTF-8-Enabled-Apache-MySQL-PHP-Markup-and-JavaScript


Effective Scala

Effective Scala

Using Traackr API

Today Engage121 announced they are launching a new version of their product that integrates with Traackr: Engage121 Launches Version 2.1

How do they do that you might ask? Well, very easy, they are using our awesome API. I thought I would show you how you can do it to. We are going to build a little Traackr widget from one of our alpha lists, Cloud Computing. The widget will display random posts from the list on a web page.

First of, the HTML for the page. Let’s keep it simple. We load JQuery because we will need it later to load the A-List via the API and display the posts.

The body contains a simple DIV and TABLE where we will display the image for the influencer and the text of the post.

<!DOCTYPE html>
<html>
    <head>
        <title>AList Widget</title>
        <script type=“text/javascript”
            src=“https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js”>
        </script>
    </head>
    <body>
        <h1>A-List Widget</h1>

        <!– alist title –>
        <div id=“alist-title”><i>Loading</i></div>

        <!– random post to display –>
        <div id=“alist-post" style="display: none; margin-top: 15px;”>
            <table><tr>
                <td>
                    <!– author's image –>
                    <img id=“author" src=”“/>    
                </td>
                <td>
                    <!– post text –>
                    <div id="post”></div>
                </td>
            </tr></table>
        </div>

    </body>
</html>

Now, the fun part. The trick it load to load the A-List via our API, here is the link for it. If you are a Traackr customer, this link is accessible from your campaign’s setting.

Once we have loaded the A-List, we can simply call the Javascript function show_post() every 5 seconds to load a new post. We select each post by randomly selecting 1 influencer from the list, then randomly select 1 channel from this influencer and finally 1 random post. Here is what it looks like:

<script type=“text/javascript”>
            $(document).ready(function(){
                $.ajax({
                    url: 'http://alist.traackr.com/influencers/all/4233.json’,
                    data: {sec: '2728ea00020714632aa811e6f4a89e3a’},
                    dataType: 'jsonp’,
                    jsonp: 'jsonpcallback’,
                    success: function(data) { show_alist(data); }
                });
            });

            alist = null;

            var show_alist = function(data) {
                // read list and display title
                alist = data;
                $(’#alist-title’).html(alist.name);
                setTimeout(show_post, 5000);
            } // End function show_alist()

            var show_post = function() {
                // Find random influencer
                current_influencer = Math.floor(Math.random() * (alist.list.length - 1));
                influencer = alist.list[current_influencer];
                // Find random channel
                current_channel = Math.floor(Math.random() * (influencer.channels.length - 1));
                channel = influencer.channels[current_channel];
                // Find channel has posts
                if ( channel.posts.length > 0 ) {
                    // FInd random post
                    current_post = Math.floor(Math.random() * (channel.posts.length - 1));
                    // get data
                    img  = influencer.pics.small;
                    post = channel.posts[current_post].title;
                    url  = channel.posts[current_post].url;
                    // display
                    $(’#alist-post’).hide();
                    $(’#author’).attr(‘src’, img);
                    $(’#post’).html(’<a target=“_blank" href=”' + url + ’“>' + post + ’</a>’);
                    $(’#alist-post’).fadeIn(750);
                    setTimeout(show_post, 5000);
                }
                else {
                    setTimeout(show_post, 100);
                }
            }
        </script>

15 min in the oven at 350 and we are done. Check out the final result

And the best part about it? Traackr’s A-Lists refresh automatically weekly, so without having to do anything, just come back every week and discover new content.

That’s all folks!


Dependency hell

Spent quality time with @bbguitar77 upgrading to Grails 2.0.0. Of course this took us down the rabbit hole to dependencies hell. But we survived, we are back and all unit tests are now passing.

Onto the next challenge!