Wednesday, September 14, 2011
On HTML and structured text as a mechanism to increase comfort of non-technical people with technical content
Saturday, September 10, 2011
Sweet Mother of God, Grails is Awesome
After the study, I got sidetracked on other projects. The data lived on the server for a long time, until I got a notification that the server was being decommissioned. The most valuable thing for a researcher may well be the data, so I quickly wrote a SQL dump out and put it in my archives.
"Hey, maybe I don't have to download the JAR and put it in the lib directory. Maybe I can try this whole 'automatic dependency resolution' thing."
So I did the following in my BuildConfig.groovy
repositories {
inherits true // Whether to inherit repository definitions from plugins
grailsPlugins()
grailsHome()
grailsCentral()
// uncomment these to enable remote dependency resolution from public Maven repositories
mavenCentral()
//mavenLocal()
//mavenRepo "http://snapshots.repository.codehaus.org"
//mavenRepo "http://repository.codehaus.org"
mavenRepo "http://download.java.net/maven/2/"
//mavenRepo "http://repository.jboss.com/maven2/"
}
dependencies {
// specify dependencies here under either 'build', 'compile', 'runtime', 'test' or 'provided' scopes eg.
// runtime 'mysql:mysql-connector-java:5.1.16'
runtime 'net.sf.opencsv:opencsv:2.3'
}
My tummy bumbled a little bit as my IDE kept yelling at me that my classes were undefined. As much fun as dynamic languages are, there's a comfort to not having those red squiggles telling you you fail at basic namespace resolution...but I resisted the urge to revert to the old school way. I ran the app...Happily, it did in fact download the dependency at runtime!
With the dependency resolved (hopefully), I turned my attention to loading the data in Bootstrap.groovy. Reading the bit on JavaBean binding gave me an idea...but I remained skeptical. Could it be so easy? On first run, the ColumnMappingStrategy didn't work. The Grails error log told me that the 2 of the values of my instance class that I expected to be filled were null. But 1 was not.
class Institution {
String name
String carnegieClassification
String schedule
static constraints = {
name blank:false, unique:true
carnegieClassification nullable:true
schedule inList:(["semester","quarter"])
}
}
universityName carnegieClassification schedule
Brown University RU/VH: Research Universities (very high research activity) semester
Ah, the carnegieClassification was binding correctly, but the other two fields were not because of mismatch in the named columns. Would the JavaBean thing fail utterly?
I minor edit later...
def createInstitutions() {
CSVReader reader = new CSVReader(new FileReader("universities.csv"));
String [] nextLine;
HeaderColumnNameTranslateMappingStrategy strat = new HeaderColumnNameTranslateMappingStrategy();
strat.setType(Institution.class);
strat.setColumnMapping(["universityName":"name", "carnegieClassification":"carnegieClassification", "schedule":"schedule"]);
CsvToBean csv = new CsvToBean();
List list = csv.parse(strat, reader);
list.each {
def already = Institution.findByName(it.name) ?: it.save(failOnError:true)
}
}
Just like that, part of the old data loaded and a roadmap found for the rest of it. No fuss, no muss, in less than 10 minutes. Wow.
Less than 3, Grails. Less than 3.Tuesday, August 30, 2011
Has the Software Craftsman movement successfully integrated with introductory software engineering?
By Nicholas Vaidyanathan
Abstract
In this paper, we explore whether undergraduate software engineering curriculums have successfully integrated some of the top advancements in the software industry from 2000-2010 into introductory software engineering courses. Advancements have touched all aspects of the software development lifecycle, including the advent of BDD/TDD, Continuous Integration and social Source Control, and the maturation of design patterns and domain driven design. In order to discover how many of these tools are being leveraged, we examined the offerings of the introductory software engineering course of the top 30 schools according to the US News & World Report and analyzed their course content to determine the penetration of these industrial innovations. We found low utilization of advancements in the field, and propose a roadmap for educators to apply moving forward.
Introduction – The Challenge
Software advances perhaps more quickly than any other field in the world. In the relatively limited time period between 1990 and 2010 alone, the industry saw dramatic shifts that changed the way the world views software. The advent of the World Wide Web, ubiquitous computing via mobile devices, and emerging virtualization have changed what industry partners seek in graduating computer science students. This monumental progression poses a challenge to software engineering educators: how can we properly prepare students to be effective professionals in such a rapidly changing field? How can educators avoid “teaching to the tool” and provide effective generalized knowledge about the software engineering discipline that doesn’t tie their students to the Vendor Lock-in AntiPattern? [1] What are the base set of skills a student needs, and tools a student should be familiar with, in order to be an effective professional in this dynamic environment?
Industrial Attention
Luckily, educators are not alone in having these concerns. Many professional software engineers have also recognized the need for sweeping changes in software engineering education. They have responded to the call by producing a deluge of important “industrial best practice” literature that seeks to educate neophytes. Andy Hunt and Dave Thomas The Pragmatic Programmer[2], Freeman and Freeman’s Head First Design Patterns[3], Fowler’s Patterns of Enterprise Application Architecture[4], Evan’s Domain Driven Design[5], Beck’s Test Driven Development by Example[6], Robert Martin’s Clean Code [7], and numerous others are vital sources that can educate and prepare students. But how effectively is such relatively recent literature being deployed in software engineering courses?
Evolution of Tools and Processes
Documentation of the sheer magnitude of the explosion of tools and processes from 1990-2010 could lead any well-meaning researcher to write thousands of pages and still fail to capture the magnitude of change, so we will full elaboration as future work. We will stick to the highlights.
Languages
The Java Programming Language[8] heralded the rise of an age of interpreted programming languages that sought to achieve platform independence. Extending this pursuit further, dynamic languages such as Python[9], Ruby[10], and others sought to eliminate unnecessary syntax and focus on allowing software engineers to build working systems quickly. These languages are now being used to explore the creation of Domain Specific Languages [11] that would allow engineers to program closer to the intended problem domain. Speed is of the essence, and is one of the hallmarks of Agile software development methodologies[12]. The rise of Agile Software Development as a methodology is well known and well-cited in the literature[], but its attendant ramifications have not been as well explored.
Requirements Specification techniques
The traditional days of SRS specifications have given way to the rise of agile tools such as CRC cards[], use cases/stories[]. Additionally, many tools such as Visual Studio Team Foundation Server 2010[] and JIRA allow business analysts to record requirements in a database driven system. This creates an emphasis on smaller artifacts that can be tied directly to the code that implements them.
Testing and Methodologies
Test Driven Development [] and Behavior Driven Development [] have sought to turn traditional development processes on their head by emphasizing testing from the beginning. Unit and integration testing have become a standard in almost every language with the rise of the xUnit family of tools. Mock Objects[] allow for simulating a live environment without directly having implementation available. BDD encourages leveraging tools like Cucumber[], which enable the creation of executable requirement specifications and end-user centered functionality evaluations.
Design and Analysis innovations
The GoF’s seminal work on Design Patterns[] has resulted in the codification of patterns in a variety of other formats. The enterprise has seen much innovation, including enterprise application architecture[4] and integration[] patterns. Patterns have also been leveraged in language implementation[], and many other areas. Patterns literature has led to evolution of architectural considerations, such as the rise of Domain Driven Design.
Source Control and Configuration Management improvements
While tools like CVS[] and Clearcase[] have offered source control and configuration management options for years, they are quickly giving way to a new breed. Recent innovations such as distributed source control with Mercurial[] and git[], web-based bug tracking and project management with JIRA[] and Lighthouse[], and continuous integration build servers like Hudson[] and Jenkins[] enable shorter development turn-around time, high project management visibility, and automated test and migration of applications between development and production environments.
Are these innovations being integrated into software engineering instruction?
Friday, August 12, 2011
An outline for open source "hack night"/mediated group coding activities
- learn about best practices
- learn about new technologies from a more hands-on approach than hearing someone else's "20 minute slideshow on Whiz-Bang.awesome. Go!"
- adjust their workflow and style by integrating with others
- express their own ideas about different architectural concepts and increase community feedback to their "I'm going to rewrite jQuery from scratch because it's a great idea" approach
- make meaningful contributions to the open source community by actually doing all this on REAL SOFTWARE, Not HelloWorld.java or Yet Another Open Source Initiative to Add to the Community.
- it's modular
- it has automated support for dependency tracking
- it's built in a language and paradigm most people learn in school (Java)
- Does the plugin documentation reflect its functionality?
- is there an overview paragraph?
- A set of user stories?
- a class diagram?
- a JavaDoc for API type of stuff [I honestly have no idea how Grails Docs are generated]
- Do the tests fully stress the constraints and methods of each (Should we explore translating the generated user stories into BDD style tests using functional plug/cuke for grails/something else?)
- domain class
- service
- tag lib
- controller
- Does any security sexorcist wanna lead a session on common patterns of attack vectors that grails controllers could be vulnerable to and the types of tests we can write to test their efficacy?
- Are there boundary conditions that the tests are missing? (i.e. things the app should NOT do that are not being tested)
- How do we split this up? Each person takes a card and works on it? Work in pairs? I guess it depends on how many people show up. I'd love to do some XP with an experienced Grails dev myself.
- Is localization well supported?
- Is there clean separation and proper coordination between the controller layer, service layer, and domain object layer (e.g. is the controller doing heavy processing that should be moved to a service?)
- Are the views too big (are there opportunities to break stuff up into partial templates?)
- Does the domain model "do good things?"
- (for example, I know Joseph showed off an example of doing M:M using two hasMany at the JUG presentation. I am *highly* of the opinion that that sucks, and these should be broken up into other classes via Scott Davis' Tutorial series and the Spring Security PersonRole approach...I am, however, open to persuasion after engaging discussion :)
- is the code "clean"?
- Good variable naming
- short methods
- classes that read like newspapers
- ...other tidbits from Martin's book
- Fix problems identified in analysis. Fix them similar to style in testing phase, and run tests after changes to make sure stuff passes (Sugar points to someone who setups Jenkins for this. I would, but I've never used it. It seems like the "right kind of thing to do")
- What functional extensions could the plugin accommodate?
- write BDD functional spec, unit tests, and test driven approach to add features
- add features
- finalize branch changes, send out announcement to grails mailing-list, merge changes into plugin repository and release
- What other plugins may be advantageous to leverage?
- What other plugins may use this one?
- What did we learn?
- What other plugins should we look at?
- iPhone or Android? (HOLY WAR!)
- MOAR Beer.
Saturday, May 14, 2011
On Framework Management
I like to analogize the situation to a 12 year old boy who eats a lot everyday, from healthy salads to Twinkies and Mountain Dew, without exercising. He just knows that the food tastes good and he enjoys it. Then, before he knows it, he explodes to 300 lbs. Suddenly doctors are warning him about heart conditions. Worse, in a few years he'll want the attention of the most beautiful girl in school, but may very easily scare her away with his excessive breadth.The boy will be in trouble until he changes his habits and begins to exercise away the accumulation that can literally crush him under all its weight.
Similarly, even useful frameworks can traumatize developers with features that promise easy use but then fail to provide the tools necessary (documentation, functionality, intuitiveness) to make good on those promises. For example, take most CMS systems. They can sometimes give wonderful "quick-win" solutions for simple tasks, but often lose favor with developers who have to do anything "more complicated."
The problem is, most OSS communities are focused on pushing new features and functionality. They are also by nature inclusive. Normatively, one can argue that the end goal should not be to erect significant barriers to contribution, as that goes against the spirit of the movement.
At the same time, without active review of contributions and acceptance of good ones, rejection of bad ones, and elimination of old ones that are super-ceded by "new and improved" ones, "plug-ins" become very analogous to what happens in the human body when cancer afflicts. Cancer is, biologically, unrestrained growth. A condition that occurs when cells "refuse to die" as a result of mutation. Just as the system that is the human body is destroyed by this unchecked process (a "biological memory leak"), so too can such processes dramatically affect the usability and adoption of OSS systems.
The solutions in the biological case for the maladies of unchecked growth are: change in process, actions (fat kid= eat less, exercise more) and introduction of external agents to eliminate problematic elements (cancer patient= chemotherapy and radiation). One can make the case that many OSS projects are already or becoming "fat." While it's probably too early to say there are any "cancerous" OSS projects, the potentialities are already there.
The problem is fundamentally one of governance. Abstractly, one could consider it to be the same problem the United States Federal Government has today: unlimited feature creep leads to unchecked expansion of the system base. Soon the system becomes so hefty that velocity of new development slows down or each new feature has massive unintended consequences.
This is the same lesson Windows has been learning for years ("My system doesn't work! Windows sucks! [Actually, it's because I'm using software X with hardware Y in configuration Z and one of the drivers was incorrectly written.]" Now other systems are experiencing it as well, such as Drupal 7 which had dozens of modules that claimed they "would be ready on launch day" but were still in Alpha/Beta stages, and which regularly have bugs reported such as "Drupal 7 doesn't work because of ___ [broken module]"
Resolution is seemingly impossible for the problem of unlimited feature creep. It is, after all, human nature according to Economics (see: scarcity). Mitigation comes from recognizing the problem and creating an according infrastructure to address it. We already have an example for this, if we once again turn to the human body.
The human body does not only contain red blood cells, or have organs for the sole purpose of "achieving functionality" (arms, legs, etc). It also has white blood cells, and organs like the liver whose duties include the elimination of impurities. There is an immune system in place that actively handles maintaining the health of the body. Most software systems have no such components. We consider a system "healthy" if it doesn't have a lot of outstanding bugs and meets most user needs. But such a view can be analogized to surmising that because a person doesn't have a disease, they are healthy. Absence/minimization of maladies can be one useful indicator, but as many in the medical industry are coming to believe cannot by itself give the "whole medical picture."
In small software systems, as in children, an under-developed immune system results in manageable fragility. Healthy children have just enough immunity not to perish from pathogens and develop resistance with respect to time. It can be expected that small software systems can mimic that cycle of maturation through build->test->release->patch cycles. If the "immune system" of the software develops throughout its maturation cycle, i.e.) as new features are added, active refactoring eliminates waste and inefficiency, regression testing verifies system health, etc, the system can be said to be healthy and likely resilient to a variety of maladies.
Larger software systems face a different set of constraints. Frameworks for application development, for example, can be analogized to natural ecosystems. In natural ecosystems, there are predator/prey relationships. These relationships have to be in harmony in order for the system to remain sustainable. Software frameworks often advertise themselves as "ecosystems"...but what are the predator/prey relationships? Are other frameworks "predators?" Only in higher-order ecosystems.
Within a framework itself, the "modules" or "plugins" must comprise the "predators/prey." They compete for community mindshare and usage, as such they sometimes conflict and sometimes work complimentarily. In order for the overall system to remain healthy, sometimes new modules must eat old modules or old modules must consume specialized features offered by new modules. This consumption can only happen if modules are actively removed from the "availability pool." Instead, many OSS frameworks currently function like deserts with no vultures. The rotting remains of ancient and broken modules litter the landscape. Many times it is up to the module developers themselves to clean up their mess, which can be analogous to asking a corpse to dispose of itself.
Whereas nature has itself created a "governance" whereby specialized organisms exist to "remove the dross"/"recycle old elements", software frameworks have no natural mechanisms. We have to "write our own garbage collection." Consequently, it is of fundamental importance for framework architects to take such considerations into account throughout the evolution of a framework, lest the system becomes ultimately unstable and breaks down. If nothing else, policy must be established to determine how the ecosystem will be managed.
There are a variety of approaches available to handle stablization of the ecosystem. Some automated, some not. For example, we could imagine a tool that periodically purges old modules based on a variety of metrics. Perhaps if a module is released as a "beta" for more than 1 year and has no activity in the form of source control repository updates or releases, it should be removed. When other users "fork" or create sub modules that leverage that module, which themselves have activity, the old module's activity log can be updated (hence, the module is active, in that its lineage is). This requires the ability to store relationships between modules, which most centralized repository tools such as Apache Maven already have.
Once we have this ability, we can do more. We can tag "active" modules with functionality descriptors which allow us to scope out the "range" of the module. Simple tagging can allow us to create "feature matrices" whereby modules can be queried, such as "give me all the modules that can draw 3D bar charts using Javascript." Grouping modules of related functionality allows for comparison between the modules. For example, Grails has developed a very basic tagging and user rating system where the community can participate and rate modules. This works for a simple metric. It is of course fairly subjective, and gives no insight into the actual implementations of the modules, only the perceptions of their functionality from end users. A more advanced approach would use that rating as part of a metric that combines other factors. For example, basic test applications can be written as "benchmarks" for the modules. These benchmarks can be used to compare the functional efficiacy/equivalence of modules (e.g. For this given Animal domain object, generate a PDF. Assert that each module can do it, and that the output files all contain the animal's name) and their relative performance (in terms of processing time, memory allocation, and other low level metrics). These benchmarks can even integrate code analysis tools to evaluate the modules and produce comparisons on LoC, convention issues, potential bugs/memory leaks, etc.
Benchmark analyses, in conjunction with user ratings and other metrics, allow us to define a common "domain" for the grouping of modules. Combined with the range, we can develop axes for evaluation and comparison. Plotting these modules in the community derived "suitability space" would enable framework architects and module developers to graphically compare modules. This can lead to pooling of efforts, elimination of unfit modules, and even refactoring of large modules into sub-modules. It can also provide clues as to what "third party components" should be investigated for integration into the framework core. If certain modules are so widely adopted they're almost considered part of the core, they can be integrated. Alternately, the core can remain relatively stable and small but "flavors" of the framework with popular modules (that encapsulate a set of pre-defined common functionality requirements) can be developed.
Such use cases, automated pruning of dead modules and benchmarking of live ones, lend themselves to automation. Such automation, however, still requires manual involvement. The metrics for pruning must be established and benchmarks must be developed by the community. This leads to a greater point. It's not enough for framework architects to focus solely on extension of framework capabilities and elimination of bugs and issues within it. Just as software projects require testing, refactoring, and overall quality assurance staff, so do software frameworks. Perhaps on a larger scale. Most frameworks up to this point have taken the approach of a human body with all red blood cells, and no white blood cells. They grow in scope and size without dedicated teams that seek to contextualize that change and modify the architecture accordingly.
For example, ASP.NET was eager to add lambdas and LINQ in revision 4. Yet the ASP.NET web application component still offers almost a myriad of ways to get the base path of a server, with very little guidance as to the merits/demerits of each or even investigation as to whether some of those should be refactored/removed. This suggests that it has not been a priority within the framework architect's enclave to maintain architectural unity and strive for simplicity. These are fundamental requirements espoused by Brooks in The Mythical Man Month for successful software endeavors, and Booch has also explored the need to combat increasing entropy and inertia by concentrated effort in his series, On Architecture. .NET is certainly not the only example, of course. Some have taken to calling the Java Programming Language an "everything and the kitchen sink" endeavor, which some hypothesize delayed the release of Java 7.
It's not uncommon for any widely used and successful software framework to run into these types of issues. Successful mitigation strategies are rare. Mainly because scale was "unplanned for", and no established quality assurance planning was integrated in the beginning.
Successful framework architects must establish a "governing board" of minds who oversee and debate the evolution of the framework. Part of that board must include a review board that actively manages the framework ecosystem. In fact, one can argue that as a framework grows in user base and module scope, the amount of effort to maintain the ecosystem should begin to parallel and in some ways even outstrip the efforts to improve the core. This quality assurance involves more than just filing bug reports on core features and write test plans. Rather, these users should help develop the benchmarks, taxonomize the overall ecosystem, and provide guidance in the form of documentation and refactoring support to module developers within that ecosystem. For example, within the Java framework matrix multiplication is offered by many modules. A "mathematics functionality coordinator" could contact the lead developers of the different modules and work with them to establish benchmarks to compare them against, as well as common interfaces that would allow for intercommunication between that piece of functionality with others. Java has already done this successfully with the Java Persistence API.
Framework evolution, especially in the Agile age, is a chaotic and rapidly changing process. This is part of the joy of software. But that joy is not without its hidden pitfalls. The point is not to slow down the rate of progress to avoid those pitfalls, but rather understand that energy must be expended to overcome them through active management of ecosystem. Frameworks need to lose some fat too, lest they find their lunch eaten by smaller, quicker frameworks that gain more mindshare for their simplicity.
Grails PDF output: PDF versurs Rendering plugins
This is exactly the type of thing that happens a lot in open source communities. There are often many plugins which seem to do the same thing. As a poor end "user" (a developer relying on someone else's code), pretty much the only thing you can do is download it and try it out.
I decided to try the PDF plugin. For one, it has better ratings in the "plugin rating system" of Grails. Plus, the original version was written by Glen A Smith, who's a co-author of my favorite Grails book, Grails in Action. Surely, that would be good, right?
...Here I am, 4 hours later. After twiddling with PDF for hours, I just installed and tried the Rendering plugin. Got out of the box functionality in 10 minutes. Ouch.
I had a fairly simple use case where I wanted to render the results of a partial template as a PDF. I struggled along the learning curve of the PDF plugin. I was not very impressed with the its documentation (or the fact that it polluted my project with its views as a way of providing documentation), and after figuring out different things (Did the pdfForm tag accept views in other directories, or did they need to be in the pdf/ directory? How do I pass parameters to my template? The simple case of passing primitives is covered by the demos, but what if I want to pass a domain object with pre-populated values that the template is supposed to reference?) I got stuck on it with some Null pointer issues generated by the plugin like so
I consequently tried the Rendering plugin, and got that working quickly.
Looking at the specs and code of the PDF plugin, it's not surprising. It's been around since Grails 0.6, and its code under the covers doesn't seem to be as modern or flexible as the Rendering plugin. I could be wrong, but it seems like the Rendering plugin has more community support and functionality moving forward, while still managing to get the special purpose job of PDF generation done pretty well.
For convenience, I created a sample project with both to showcase the problems I ran into. It is available here. Perhaps they stemmed from ignorance. I invite others to give it a try and respond with comments.
Tuesday, April 26, 2011
Robust Web Application Charting in Grails
Using JFreeChart is really easy in Grails. Here's a quick recipe:
- Download JFreeChart and JCommon jar files
- Place the jar files in the "lib" directory of your grails-app
- When you want graphs, import them and use them as regular jar files, like so:
Using JFreeChart in a Utility class
I find that it's generally good practice to encapsulate dependencies, so I created a class to wrap drawing that essentially follows the example given in the JFreeChart source for creating a dial chart. Then, I created a service to handle charting, since that is something that I expect to use in many controllers (DRY is good)
Creating a Service to manage drawing
Using this service in my controllers becomes really easy.
Controller
View
This was all well and good...until I viewed the images. They're ugly. Pug fugly. Like, ugly ugly.

So what's a boy to do? Well, I found a cute little library called HighCharts. Its graphs are sexy. They're fairly easy to make, too. So I built one. It was cool. Now I was going through the odious task of removing JFreeChart. Why?
- its added a lot of bloat to the code
- it's not good to mix approaches for doing the same thing in different places
Just as I was about to remove JFreeChart, I realized something: I had switched my charting approach from server-side to client-side. Good for processing. The client-side implementation relies on Javascript, of course. What if it was turned off? That could be a 3am support call...so should I do everything in JFreeChart?
Until I remembered my old friend, the <noscript> tag. If I use that, I have a configurable approach. If Javascript is enabled, make a HighCharts chart. If not, I still have my old server side chart ready to go.
One could argue that worrying about Javascript being turned off in this day and age is silly. Plus, managing both libraries and mechanisms for chart drawing is a maintainability concern moving forward. But in so doing I get some functional robustness.
I'm fairly certain the trade-off between robustness and efficiency/ease of maintainability is fairly common. The correct resolution of the tension of these forces depends on the requirements. Nevertheless, it's a good thing to look out for:
If your server side code can avoid doing stuff, avoid it by doing it client side. But keep the flexibility in there in case the client side can't.