Category Archives: grails

Catch my #Grails talk @springone2gx!

I’m speaking at SpringOne 2GX next month. I invite you to come see my presentation: “Case Study – Grails in the Real World“.

I have been working hard for some time on other material that will be presented at SpringOne. With that stuff briefly off my plate, I have dove head first into getting my presentation ready! There isn’t a lot of time. I got a hold of the template for our slides and have been writing raw material, slowly trying to morph it into a top notch presentation.

What are you talking about?

Most of my presentation is aimed at showing off a Grails app I built about several months ago. The app’s purpose is to serve up maven artifacts for our commercial tc Server product. The latest version of tc Server now has the embedded Tomcat feature, and to use it, many developers are interested in simply adding a maven dependency to their project.

We essentially wanted to provide this feature free to developers, but still track download statistics. So I set out writing a Grails app that allowed you to register by email address and then give you the settings to plugin into your maven build file. It works great! The Grails app is essentially a proxy server. It pulls down the files from our super secret location, and forwards them to the requester.

Growing pains

I went through a lot of growing pains making it all work. You register online with an email address. The app sends you an email with a hashed activation code. You have seven days to activate or the link is thrown out.

At one time, we generated a random hash link that you can see after account activation. Later on, that was replaced with an authenticated REST endpoint with extra steps to configure that for maven.

The whole time, I wanted to share this with other developers that might be going through some of the same pains as me in making it functional, durable, easy-to-use, and able to withstand a barrage of customer-driven mistakes (which always happen!) It was also reminiscent of work at my previous job where I built a 24×7 Ops center that managed a nationwide network. My team ran into a whole host of technical and customer issues, and I’d like to think that my experience there helped shape things on this Grails app.

If you come to my talk, you will get to walk through these various bits of the app and hopefully learn some tactics to help your own development efforts. Given that the production app contains secret email passwords and other proprietary information, I had to make a sanitized version of the app. That is mostly done with just one thing remaining. Hopefully, it won’t take too much work to orchestrate the presentation.

Even if you don’t catch my presentation, I strongly encourage you to sign up for SpringOne 2GX. This is one of the best conferences out there, with some of the best people in the industry coming to speak from around the world.

Bootstrap and jQuery make me look good

I recently was given a task that seemed kind of big for me. I had to generate a web site targeted for a certain with little time. I put off planned vacation time in order to meet this schedule.

Bottom line, I spit out the site, and to top it off, my co-workers were impressed with my work. I had picked three key technologies:

  • Grails
  • Twitter Bootstrap for styling
  • jQuery for incidental refinements
Grails was the ticket to rapidly building a web site that not only was easy to create, but had mature plugins like Spring Security, ability to map some URLs for customized REST points specified in the requirements, and easy ability to manage database evolutions. Grails also comes fully loaded with Spring which through its MailTemplate made it easy for me to build an email-driven registration system.
But Grails was just the beginning. I had been tinkering in my spare time with learning how Twitter’s Bootstrap layout library worked. It was fantastic and let me quickly build a professional looking site. I learned how to use the various classes to lay things out. Then on the input fields, I was able to easily tag required fields. Bootstrap provided convenient validation. I even marked up certain fields using the HTML5 “email” types, and Bootstrap would trap entries that didn’t have email fields and alert the user.
Finally, I needed to force users to scroll through a EULA, and that is where a bit of jQuery did the trick. I had jQuery only enable a checkbox when they scrolled to the bottom, and then clicking on the checkbox would in turn enable the submit button.
All of this may sound like Web Programming 101, but what you probably don’t realize is that for the past 10+ years, I have worked on thick client interfaces using Swing and other things. I am a real newbie when it comes to HTML, CSS, and JavaScript! But tools like these define a whole new style of programming. Based on what I’ve seen, today’s web programming paradigm isn’t the same as what it was five years ago.
That means I don’t need to catch up on how people built web pages 5-10 years ago. I need to learn what people are doing today. And tools like Grails, Bootstrap, and jQuery tell me that this is in my grasp. My fundamental skills as a programmer are still useful even in a paradigm I sidestepped for 10+ years.
Maybe some people would consider my web-based skills impure because I lean on these libraries too much. I admit I probably couldn’t build these things if I had to. But that doesn’t matter. When people were building up the web 15 years ago, they never imagined many of the standard things we use today. And what does it matter? If the site looks good and works, that’s what counts, right?
This makes me excited to work on the “next” website. These tools make it really fun. Even now I’m learning how to customize the look-and-feel of Bootstrap. I’ve already plugged in a custom font. After a bit, I might figure out how to customize the navbar. All good stuff.
Happy programming!

Spring Python 1.0.0 (RC1) is finally here!

This is an exciting day. The first, production-ready version of Spring Python is finally here. Version 1.0.0-RC1 is out. You can download from the official site, but if you are having trouble, you can go directly to S3, and grab 1.0.0-RC1. Please visit the official website at, where you will find links to up-to-date documentation, support options, and anything else you might need. Please click here to check for any dependencies you may be missing, so you can in turn download and install them.

Be sure to grab:

  • springpython-1.0.0-RC1.tar.gz
  • springpython-samples-1.0.0-RC1.tar.gz

You DON’T have to install the springpython-gen-cherrypy-plugins!!! See later section for the reason why.

What is Spring Python?

For those of you new to this project, Spring Python takes the concepts implemented by the Spring Framework (Java), and applies them to Python. This provides a powerful library of functionality to help you get back to writing the code that makes you money.

A little history

I have been working since October 2006 on this project, and it feels good to make this release. What do we mean by “production-ready?” The APIs are frozen until the next major release, so you have a stable platform to work against. This is a Release Candidate, meaning if there are critical errors, please report them so we can fix and release, until we reach general availability (GA).

I want to personally thank the many people who have helped make this release possible, including: Russ Miles, Sylvain Hellegouarch, and Dennis Mendelson. Also, a big thanks to SpringSource for hosting this project. And I also want to thank the Spring Python community that has posted questions, comments, patches, and ideas. BTW, Uche, your amara toolkit really saved the day in XML parsing!

Release Notes

Release Notes – Spring Python – Version 1.0.0-RC1

** Bug
* [SESPRINGPYTHONPY-87] – Fix object.html documentation to use proper import for ApplicationContext
* [SESPRINGPYTHONPY-88] – Fix PyroServiceExporter so that it has configurable host/port settings (w/defaults)

** Improvement

* [SESPRINGPYTHONPY-62] – Add XML configuration documentation to reference documents.
* [SESPRINGPYTHONPY-84] – Generate digital signatures for uploaded items automatically
* [SESPRINGPYTHONPY-89] – Repair springpython.context.ObjectPostProcessor to work more like BeanPostProcessor

** New Feature
* [SESPRINGPYTHONPY-83] – Create a command-line utility with a plug-in system that can perform useful tasks

Spring Python has a command-line tool with plugins!

While we have been working on many key features over the life cycle of this project, the biggest feature in this release is our command-line/plug-in system. During the SpringOne Americas conference, I was blown away by Graeme Rocher’s demo of Grails, where he built a twitter clone app in 40 minutes. A key part was his command-line grails tool.

Before I left that presentation, my mind was already racing in how to build a similar tool to help Spring Python developers. I realized I needed a pluggable solution, so that many different plugins could be created, whether by me or the community. During a few of the other presentations I attended, I was coding a simple solution that would support version control of plugins, being able to download and install from an official source, having some command-line help, and being able to install/uninstall/reinstall. To go along with this, I cooked up one plugin, gen-cherrpy-app, that creates a skeleton CherryPy web application with an IoC container configured with basic components, including security.

To use this tool, just download and install the main Spring Python package. After installing, you should find coily installed on your path. To get started, see what coily has to offer.

% coily --help

You should get something like this:

Coily - the command-line management tool for Spring Python
Copyright 2006-2008 SpringSource (, All Rights Reserved
Licensed under the Apache License, Version 2.0

Usage: coily [command]

--help print this help message
--list-installed-plugins list currently installed plugins
--list-available-plugins list plugins available for download
--install-plugin [name] install coily plugin
--uninstall-plugin [name] uninstall coily plugin

--reinstall-plugin [name] reinstall coily plugin

coily will create a local ~/.springpython directory, which contains all installed plugins, on a per-user basis. Currently, there is one official plugin which is used to help you create a CherryPy application. However, the opportunities are endless. Grails has plugins to create apps, modify existing apps, and so on. We can grow in a similar fashion.

Remember when I said you don’t have to install springpython-gen-cherrypy-app? Guess what. coily will grab it for you. You don’t have to install all the plugins. You can pick and choose what you want. At this stage, we don’t have an upgrade feature. But if you reinstall, it should do the trick.

Plugin Explosion

One issue Grails is having to deal with is their explosion of plugins. They have a lot, and only a subset are managed by the core Grails team. Others were developed by the community. This is definitely a good thing, because it reflects widespread adoption of Grails. However, anyone new to the project cannot discern the status of each plugin, and be able to decipher the stable ones from the bleeding edge ones. This is where Spring Extensions comes into play!

Spring Extensions is the official incubator process SpringSource has developed to manage new software development. Each extension has its own life cycle, forum, and tracked issues. Spring Python is an extension, and currently it contains one plugin. New plugins can fit into one of three possibilities:

  • Become an official part of Spring Python, meaning it is managed by the Spring Python team.
  • Become a separate, official Spring Extension, meaning it is not part of the official Spring Python release, but instead, has its own life cycle of releases, and potentially different leader and team.
  • Be managed outside the entire SpringSource system.

All three of these choices are good. They each offer a way to extend Spring Python in a usable way. Maybe you want to start an extension, but want to tip toe a little before diving in. Great! That is how lots of open source projects start. Later on, perhaps your plugin is becoming popular, and you would like to make it more official. A Spring Extension gets branded as officially supported by SpringSource. The amount of support varies, meaning as a minimum you get access to tools and some web space. Perhaps someday, if it becomes really popular, it can potentially join the SpringSource software portfolio. Or…not. No promises are made!

What else have you got?

Enough about plugins. What else is there, you ask?

  • Inversion of Control – a container which supports several formats, allows you to wire your python application together simply and effectively.
  • Aspect Oriented Programming – add extra services to existing code without changing APIs.
  • Data Access – DatabaseTemplate is a very useful abstraction to make writing database calls easier. This isn’t an ORM, but makes it easy to write pure SQL operations.
  • Transaction Management – while database calls are useful for any small, medium, or large application, transactions are the bread and butter of enterprise apps. This makes it easy to wrap business logic in transactions, whether or not it is the data access layer.
  • Security – using AOP, this is another powerful layer to add on. It is based on the architecture of Spring Security, meaning it is just as flexible and powerful, whether you are building a web app or a desktop client.
  • Remoting – RPCs are the building blocks for distributed apps. Most enterprise apps need to grow beyond the limits of a single server at some stage.

Each of these features, when orchestrated together, makes it easy to build enterprise-grade applications. IoC provides the indirection that allows you to convert a simple, one-machine, client-server app into a multi-node, security layered, scaled application with transactional protection. And everything is POPO-based.

What are POPOs?

Spring Java works hard to make sure it support POJO-based solutions. POJOs are plain old java objects. The idea is you don’t have to extend the frameworks classes. Instead, you can retool code you already wrote with minimal effort. Spring Python takes this same concept to Python by using POPOs, or plain old Python objects.

There are useful utility classes you can extend, but you don’t have to in order to use this collection of libraries. And that’s the point! You only use what you need, when you need it. The choice is yours.

Join us at LinkedIn

Please come and join us at the Spring Python group on LinkedIn.

What else is coming?

Whew! It has been some hard work to get to here. But by no means are we done. There is plenty more to do to make Spring Python better. A lot of the work done has been foundational.

Spring Python’s security module has a strong architecture in place. Now, we can start coding authentication providers to support things like LDAP, X.509, SecurId, two-factor authentication. Plenty of places to go there!

Remoting currently supports Pyro (Python Remote Objects) and some basic Hesssian. But there are many other remoting protocols. We have the foundation in place to code more service exporters in order to integrate with other technologies.

There are plenty of places to go from here. And we aren’t slowing down!

SpringOne – Days 1 and 2

I finally found some time to post updates. Whew! It has been busy!

Day 1
On Monday, I hooked up with the SpringSource guys. It seems everyone had something to work on. I wanted to get 0.9.0 completed and working before giving my demo of PetClinic on Thursday. Just about anyone I spoke to was polishing up their slides. It is truly fantastic to be chatting with the guys at SpringSource.

Rod Johnson gave the keynote addresss, focusing on the target goal of SpringSource in reducing the complexity of application development. Complexity means more development, more risk, and in turn, more cost. SpringSource’s overarching goal of reducing complexity must be working, because he had several metrics showing how much has been adopted in some degree by the industry.

After the keynote, I was finally able to meet up with Keith Donald. We have been playing email tag for some time, and I was surprised to find out his office is probably 10 minutes away from mine. Hopefully we can get together soon after the conference. It was also great to meet Mark Pollack, Chris Beams, Ben Alex, and of course, Rod Johnson himself. While I enjoy reading their blog entries and source code, there is no substitute for meeting the real person.

Day 2
In the morning, I attended the Grail presentation. That was awesome. Graeme demonstrated building a twitter-like site using Grails in 40 minutes. Okay, he promised 40 minutes, and took 45 minutes, but only because he started adding extra functionality not found at the actual twitter site. In the process, I was realizing the value Grails places on plugins. Grails is good at creating a skeleton application, and then letting you flesh it out. I was starting to get the idea that Spring Python could use a command line utility with plugins to generate a skeleton CherryPy app, Django app, or anything else developed by a plugin. Well, I went to the next session, “Intro to Spring Security 2.5”, opened my laptop, and started coding. I managed to write a static skeleton app, and then began working on a command-line utility to dynamically generate this. That is still in progress.

I admit I was only listening with one ear to Ben’s presentation. Sorry Ben! 1) I am already somewhat familiar with Spring Security, 2) most of it is geared towards web apps which I don’t write, and 3) I was really stoked at the idea of a command-line tool that download Spring Python plugins from a network location. I did catch his question, “who here is NOT writing web apps?” I was the only person in the room who raised a hand to that. When asked what I was using, I answered “Swing desktop apps.” That plugged Ben’s point that Spring Security uses the same tactics.

After lunch, I attend two sessions about Spring Integration. This is channel based messaging, which is sort of like JMS on steroids in my book. They interface with JMS, but also with other things like file-based systems, web services, RMI, anything. And it is easy to plug in your non-message based service to a chain of processing. This is wiring your app in a different, more decoupled way. I sure could have used this about five years ago.

Later that evening, Russ and I got together to work on his Spring Extensions presentation. Russ is planning to talk about the process Spring has set up to better manage new code, and wanted to compare the process with real life, and Spring Python is his choice target. If you are at SpringOne and can read this before Thursday, I highly suggest you attend that presentation. It will definitely be entertaining (shameless plug).

SpringSource has acquired G2One, the company behind Grails and Groovy.


I posted this in case you hadn’t heard, SpringSource has acquired the company behind Grails and Groovy.

You may wonder “what has this got to do with Python?” Well, I am always interested in tracking what SpringSource is up to, especially in the realm of dynamic languages. This is good news to me, because it shows SpringSource’s keen interest in this arena, which is also good for Python.

SpringSource acquired G2One