Saturday, May 31, 2008

GSoC 2008: Week 1

Okay, week 1 is nearing an end.I accomplished alot of things.

First, I completed the meta-data storage code. I wrote some tests, which revealed some bugs that needed fixing, and they were. I am happy to say, that the metadata storage works!

Writing the test was difficult due to the fact I store the forms in the system using a static List in my container class. I wound up updating to JUnit 4 to get at the @BeforeClass annotation so that the only one set of forms gets loaded into the container class. This helped me greatly. Additionally, the @AfterClass annotation was handy for cleaning up from the tests.

Secondly, Writing the code for interrogating the model was a piece of cake, thanks to groovy. All code for interrogating the model has 50 lines! That includes a model class I wrote to hold the field types and field names. I'll show you, but before I do, I should note that return statements are optional, and the final statement will be returned.

package org.openmrs.module.groovyforms.util

import java.lang.reflect.Field
import org.openmrs.module.groovyforms.metadata.model.GroovyFormsDomainModel

* Utility class containing methods for class interrogation.
class GroovyFormsClassUtil {
* Interrogates the class for all declared fields and
* stores the type and name in a container class
* @param the [email protected] Class#getCanonicalName() canonical name of the class}
* @see Class#getCanonicalName()
* @return a reference to a container class containing the type
static def getModel(fields) {
def domainModel = new GroovyFormsDomainModel()
def names = domainModel.fieldNames.&add
def types = domainModel.fieldTypes.&add
def f = fields.each {Field field ->
types field.type.canonicalName

With groovy, it's so easy and concise (as you can see). Let's explain what's going on. First, I pass in the Field array I get from Field.getDeclaredFields(). Now, groovy adds methods onto the standard JDK classes, one of those methods is a method named each() which takes a closure. Now, back to the point, I pass a Field into the closure. That closure is executed for each element (in this case, a Field). Then I add the name, and the type to a List stored in a container class, now that container class is also written in groovy!

package org.openmrs.module.groovyforms.metadata.model

* Ths class holds information about the properties of the model.
class GroovyFormsDomainModel {

* The field names
def fieldNames = []

* The field types
def fieldTypes = []


Now, the fields are Lists, not arrays. Anyways, I've gotten off on a tangent here, so let me get back on track.

What I accomplished:

Week 1:

Code to generate the directory structure, serialization of metadata back/forth between XML and POJOs (Plain Old Java Objects), Wrote tests to ensure everything works in that regard. Additionally, I wrote the code to interrogate the domain model which I will generate the forms from.

Next Week

Write up the templates for the view/controller and write code to do the generation of the view/controller. Write some tests to ensure everything generates correctly.

Unrelated to that, my stored-value card from google came today. It feels nice to be $500 richer! This is going to be the best summer, I'm already having fun doing this. It's amazing seeing the whole project evolve into something amazing.

Thursday, May 29, 2008

GSoC 2008: Progress report

I have made a lot of progress on my Google Summer of Code Project.

First, I've completed the code for the generation of the directory structure for the forms. This is done using the form id, which is the name with all illegal characters removed. The only valid characters left are alpha-numeric and periods. Let me tell you, the regular expression to replace all of those characters was hell to write. But, thanks to the help of Jason Davis, I was able to make it much more readable and easier digest. You've gotta see it to get an idea of how bad it was, so here goes:

* Removes all illegal characters, then removes all spaces and makes it all lower-case.
* @param str the form name
* @return a viable form id.
public static String formNameToFormId(String str) {
return str.replaceAll("[\\$\\(\\)%`~!@#&;:\\^=\\+\\?<>\"\\*\\\\////\\\\{\\}'\\]\\[\\|\\s+]", "").toLowerCase();


That is pretty much hell on earth to read, and it was hell on earth to type. Here's the *MUCH* simpler version:

* Removes all illegal characters, then removes all spaces and makes it all lower-case.
* @param str the form name
* @return a viable form id.
public static String formNameToFormId(String str) {
return str.replaceAll("[^a-zA-Z0-9.]", "").toLowerCase();


Note, you can clearly see that i'm negating that entire sequence. It does the SAME thing, but is MUCH more readable. That reads: "replace everything that isn't a letter from A to Z *OR* a to z(lower case letters) *OR* from 0 through 9 *OR* a period. Whereas the above just excluded the invalid characters explicitly but was a MONSTER of a regular expression.

Secondly, metadata persistence is written in, I'm using xstream. It's a great tool for XML serialization.

That's it. Oh, by the way, these are the things I earmarked TWO WEEKS FOR! Now, I push domain class model processing up, will work on that tomorrow.

Tuesday, May 27, 2008

Ready...Set...Code: Google Summer of Code has started!

Today was the official start of Google Summer of Code 2008 Hopefully everybody is finding it a pleasant experience. I have yet to start coding as today was a US Holiday (Memorial Day).

The project plan for the summer has been finalized. I decided to set two-week blocks, rather than do a weekly thing. I chose this, as it's extremely flexible and can scale items either back or forward.

The project plan can be found here. A Google Doc which my mentor and I used to plan the project can be found here. Finally, See my general plan written as a previous blog post.

Best of luck to all the summer of code students!

Tuesday, May 20, 2008

Thank you so much Google!!

Today I got the coveted "Google Book" that all Google Summer of Code students have been talking about constantly! I've flipped through it, it's an amazing book! Want to know the name? Everybody knows it already, it's "Beautiful Code" by O'Reilly.

Thank you so much!!!!!

Monday, May 19, 2008

Google Summer of Code Status Report

I haven't really blogged since I last announced that I was accepted into Google Summer of Code. I have a phone meeting with my mentor to bang out a project plan, I more or less have a general idea of how I want things to go, and he does too. Overall, it should be a very successful summer.

I've been enjoying the Community Bonding period. I have made a lot of friends. My fellow summer of coders are amazing. I planned a potential meet-up for google soc'ers from NY, NJ and CT (to be announced formally when it is more concrete).

Now, onto the fun part, telling you all about my project and how I plan on doing it. I'm gonna break this down. There's a lot of things that need to happen. A lot of data needs to be passed between the front and back ends.

Firstly, Direct Web Remoting (DWR) will be used to grab all the information the users enter into the form and forwards it to the backend whose job it is to generate the form, and then relay it back to the user showing them the result, then saving it to the system. DWR will also be used to provide some AJAX magic.

Then, after I have the data, I need to use reflection on the Form Model and based on the data type, using a templating engine, such as Velocity generate HTML form components.

String, etc: text field or text area; Using some Groovy ExpandoMetaClass magic will aid in deciding if we use a text field or text area.

List: drop-select select box

Boolean: radio or checkbox with some Groovy ExpandoMetaClass magic, i'll add a property which will help aid in deciding which one to use.

After the form is generated, a controller will be generated with default checks that the fields are not empty. This will also be done using Velocity for templating.

Once I have everything generated, it will be saved on the file system someplace with an associated XML file containing all metadata(title,version, description,etc) which will be read in by the system when showing which forms are in the system.

Tuesday, May 6, 2008

Posting code made easier (for everybody else reading your blog!)

I've noticed something while reading my daily blogs, a lot of code is just unreadable because most blog systems (blogger looking at you), screw up indentation, unless you wrap it in a pre tag (opening and closing are both required. This makes it readable for your readers! I've left comments on the blogs that didn't know this, and now they do.

This message is primarily for the Google Summer of Code students, but is useful to the programming community as a whole. When you post code, wrap it in a pre tag and be sure to close them when your code example is complete.

Saturday, May 3, 2008

Groovy 1.6-beta-1 released!

So, i read that groovy released 1.6-beta-1. They kept the mixins syntax that was added. I love the new syntax, it's easy to use, and concise as well.

Congrats to the Groovy team! Great Job!