Skip to main content

Cocoon refactorings

I've been maintaining a complex Cocoon application for a couple of years now. Unfortunately, as the code gets older, it requires more and more time for maintenance unless you keep it clean and neat from the beginning. Finally I've found time to refactor the project gradually and I'll try to keep it this way. In this article I'm going to review the steps I've taken to improve the code and build quality.

Remove duplicated resources
I've started with removing duplicated and unused resources (mostly images and icons). Many of them were duplicated across the application in several Cocoon blocks. So I had to keep common resources in a single shared block and modify references from other blocks accordingly. For this I've added the following sitemap rule into all blocks:
<map:match pattern="shared/resource/external/**">
  <map:read src="servlet:shared:/resource/external/{1}"/>
This single improvement decreased the build time by 30% (that is about 10 seconds). Besides, I've refactored CSS files by extracting common.css that is common for all blocks and have left only specific CSS rules in each block.

Remove duplicated resources - update from 18th June
I've found a much more elegant way to achieve the same. It uses ResourceExistsSelector in Cocoon. BTW, this selector is widely used for different sitemap patterns. Here is the code that I've added to all block sitemaps:
<map:match pattern="resource/external/**">
  <map:select type="resource-exists">
    <map:when test="resource/external/{1}">
      <map:read src="resource/external/{1}"/>
      <map:read src="servlet:shared:/resource/external/{1}"/>
In comparison with the method described above, this one gives you the same block-relative URL as in the shared block. It helps to prevent issues, e.g. using background images in shared CSS files. Because in this case you'd prefer a single relative URL that is valid for all blocks.

Extract sub-sitemaps
The next step was extracting sub-sitemaps using Cocoon Mounts (official doc here). This one I had in my mind for a long time. In several blocks we had good use cases for this such as separating a file generating pipeline and a test pipeline:
<map:match pattern="file/**">
  <map:mount uri-prefix="file" src="sitemap-file.xmap"/>

<map:match pattern="test/**">
  <map:mount uri-prefix="test" src="sitemap-test.xmap"/>
Ideally you should take care about it while designing your app and you'll be able to benefit from auto-mounting and dynamic mounting.

Further steps
There is much more to improve if you check the community sources:


Popular posts from this blog

Connection to Amazon Neptune endpoint from EKS during development

This small article will describe how to connect to Amazon Neptune database endpoint from your PC during development. Amazon Neptune is a fully managed graph database service from Amazon. Due to security reasons direct connections to Neptune are not allowed, so it's impossible to attach a public IP address or load balancer to that service. Instead access is restricted to the same VPC where Neptune is set up, so applications should be deployed in the same VPC to be able to access the database. That's a great idea for Production however it makes it very difficult to develop, debug and test applications locally. The instructions below will help you to create a tunnel towards Neptune endpoint considering you use Amazon EKS - a managed Kubernetes service from Amazon. As a side note, if you don't use EKS, the same idea of creating a tunnel can be implemented using a Bastion server . In Kubernetes we'll create a dedicated proxying pod. Prerequisites. Setting up a tunnel.

Notes on upgrade to JSF 2.1, Servlet 3.0, Spring 4.0, RichFaces 4.3

This article is devoted to an upgrade of a common JSF Spring application. Time flies and there is already Java EE 7 platform out and widely used. It's sometimes said that Spring framework has become legacy with appearance of Java EE 6. But it's out of scope of this post. Here I'm going to provide notes about the minimal changes that I found required for the upgrade of the application from JSF 1.2 to 2.1, from JSTL 1.1.2 to 1.2, from Servlet 2.4 to 3.0, from Spring 3.1.3 to 4.0.5, from RichFaces 3.3.3 to 4.3.7. It must be mentioned that the latest final RichFaces release 4.3.7 depends on JSF 2.1, JSTL 1.2 and Servlet 3.0.1 that dictated those versions. This post should not be considered as comprehensive but rather showing how I did the upgrade. See the links for more details. Jetty & Tomcat. JSTL. JSF & Facelets. Servlet. Spring framework. RichFaces. Jetty & Tomcat First, I upgraded the application to run with the latest servlet container versio

Extracting XML comments with XQuery

I've just discovered that it's possible to process comment nodes using XQuery. Ideally it should not be the case if you take part in designing your data formats, then you should simply store valuable data in plain xml. But I have to deal with OntoML data source that uses a bit peculiar format while export to XML, i.e. some data fields are stored inside XML comments. So here is an example how to solve this problem. XML example This is an example stub of one real xml with irrelevant data omitted. There are several thousands of xmls like this stored in Sedna XML DB collection. Finally, I need to extract the list of pairs for the complete collection: identifier (i.e. SOT1209 ) and saved timestamp (i.e. 2012-12-12 23:58:13.118 GMT ). <?xml version="1.0" standalone="yes"?> <!--EXPORT_PROGRAM:=eptos-iso29002-10-Export-V10--> <!--File saved on: 2012-12-12 23:58:13.118 GMT--> <!--XML Schema used: V099--> <cat:catalogue xmlns:cat=