Monday, June 9, 2008

Second Week For OpenMRS Coding

Last week was really a hectic time for me and hence haven’t found much time to code or blog. A close friend Debojit is in a new Idol-like reality show called “Jo Jeeta Wohi Superstar” and we are back in the publicity campaign like we were when last time he won Saregamapa Challenge 2005. The good thing is that I’m still writing code (to game the online voting), but not exactly for OpenMRS… But I did some work on OpenMRS and nearly had a deliverable basic patient search.

The patient search on my Registration Module has taught me a few important lessons. OpenMRS’s web application uses the Model-View-Controller (MVC) through Spring Framework. I have a controller which calls some methods from the OpenMRS API and retrieves patient information. Normally, the practice is to return values from the Controller to the View (JSP here) is through the use of a bean’s getter methods. This means that the Controller sets the Bean object with the values from the database and the View (i.e. JSP) page uses to the getter methods to get values.

But instead of a bean, I tried to return a double-dimensional array and got stuck with the following... I’m still wondering why I can’t access length variable of the array. Look at the code snippets below and may be I’ll get some hints from you!!


protected String[][] formBackingObject(HttpServletRequest request) throws Exception {
        String[][] searchedPatients = new String[0][0];
        if (request.getParameter("phrase") != null) {
            List<Patient> patients = Context.getPatientService().getPatients(request.getParameter("phrase"));
            searchedPatients = new String[patients.size()][8];
            for (int i = 0; i < patients.size(); i++) {
                searchedPatients [i][0] = (patients.get(i)).getPatientIdentifier().getIdentifier();
                searchedPatients [i][1] = (patients.get(i)).getGivenName();
                searchedPatients [i][2] = (patients.get(i)).getMiddleName();
                searchedPatients [i][3] = (patients.get(i)).getFamilyName();
                searchedPatients [i][4] = String.valueOf((patients.get(i)).getAge());
                searchedPatients [i][5] = (patients.get(i)).getGender();
                searchedPatients [i][6] = (patients.get(i)).getTribe().getName();
                searchedPatients [i][7] = (patients.get(i)).getBirthdate().toString(); 
        }"# of patients found: "+searchedPatients.length); 
        return searchedPatients;           
        return searchedPatients; 

This String[][] called searchedPatients can be accessed as registrationForm according to my moduleApplicationContext mapping. But in my JSP page when I try to access the .length variable of the registration form there seems to be a problem.


<c:forEach var="row" begin="0" end="${registrationForm.length}">

I get an error where the JSP page throws a NumberFormatException for “length” input. Now I was baffled why it was trying to take “length” as input string, when it should have taken the length of the array as its input.

Anyways, with the Bean the current patient search is working, but I have to get back to coding quickly and build a good UI, for which I’m using jQuery. With jQuery I plan to implement AJAX and also some simple but useful UI improvements. Next in-line is searching using the barcode reader and a lot more left to do… Hopefully, I’ll do more!!

1 comment:

Ben Wolfe said...

Why not do this in your jsp:

c:forEach var="row" items="registrationForm">

${row[0]} ${row[1]}

You'll want to use ${fn:length(registrationForm)} because when you do ${registrationForm.length} jstl actually tries to do registrationForm.getLength() in java.

Why not return a list of mini objects from registrationForm.getRows() ?