Chariot Training Classes

Training Courses

I run Chariot's training and mentoring services. We provide training in AngularJS, HTML5, Spring, Hibernate, Maven, Scala, and more.

Chariot Education Services

Technology

Chariot Emerging Tech

Learn about upcoming technologies and trends from my colleagues at Chariot Solutions.

Resources

Chariot Conferences

Podcasts

« Quizzo in Roo - Security, SHA-256 and OS X | Main | Quizzo in Roo, Introduction »
Sunday
Feb192012

Quizzo in Roo, truth be told

Truth be told, I've spent so much time running a training practice, writing a book and dealing with Rails apps that my brain needed a bit of adjustment to long-form, more than one day coding assignments. I tried to start with a simple JPA/hibernate model, but the mental feedback loop, even with Roo at the helm, was too slow for me.

(Remember, I am on a two week deadline right now to write two presentations AND get the quiz working if I have a shot at this. So I am trying to control a flailing feeling. And thinking that I'm only doing one presentation next time.)

I went through three stages of thought before writing this down:

Stage 1 - Let's focus on the model

I figured that the data was key, and that I could model from the database up. I ended up floundering after a few hours of this, realizing that we have two problems here - the model of the quiz structure, and dealing with running instances of the quiz, recording answers, and reporting results.

The results were rather throwaway, so I won't bore you with them.

So, I went to Stage 2

Stage 2 - Go all design-patterny on it

Ok, focus on the objects and the in-memory model. That was a great turn, as it got me thinking about the contracts, building up the objects, etc. I figured I could have a Quiz in-memory model, and that I could build it using a builder. So I spent time writing up builders that looked something like this:

package com.chariot.games.quizzo.model.quiz;

public class QuestionBuilder {
  
  Question question;
  public QuestionBuilder() {
    question = new Question();
  }
  
  public QuestionBuilder title(String title) {
    question.setTitle(title);
    return this;
  }
  
  public QuestionBuilder choice(Choice choice) {
    question.getChoices().add(choice);
    return this;
  }
  
  public Question asQuestion() {
    return question;
  }
}

Then I could use the builder in tests, ala:

  @Test
  public void testBuildQuestionWithBooleanAnswer() 
     throws CloneNotSupportedException {

    Question q = new QuestionBuilder()
                  .title("Studies say people are crazy.")
                  .choice(new ChoiceBuilder()
                          .booleanChoice(true)
                          .text("They are crazy")
                          .asChoice()
                  ).asQuestion();

      assertEquals("Studies say people are crazy.", q.getTitle());
      assertEquals(1, q.getChoices().size());
      assertEquals("They are crazy", q.getChoices().get(0).getAnswerText());

      assertEquals(BooleanChoice.class, q.getChoices().get(0).getClass());

      Question q2 = q.clone();
      assertEquals(q2, q);
      assertNotSame(q2, q);
  }

Stage 3 - Prototype quickly on paper, models again

But in the end, what I really need is a quiz definition, with questions, etc., and I need to persist them at some point. So, it was fun, and helped me understand the relationships, but back to JPA.

My model so far...

Ok, so far I have the following model elements:

@RooJavaBean
@RooToString
@RooJpaActiveRecord
public class Choice {

    @NotNull
    @Size(max = 300)
    private String text;

    @NotNull
    private Boolean correct;

    @NotNull
    @ManyToOne
    private Question question;
}

@RooJavaBean
@RooToString
@RooJpaActiveRecord
public class Question {

    @ManyToOne
    private Quiz quiz;

    @NotNull
    @Size(max = 300)
    private String text;

    @OneToMany(cascade = CascadeType.ALL)
    private Set<Choice> choices = new HashSet<Choice>();
}

@RooJavaBean
@RooToString
@RooJpaActiveRecord
public class Quiz {

    @NotNull
    @Size(max = 200)
    private String title;

    @NotNull
    @Size(max = 500)
    private String description;

}

@RooJavaBean
@RooToString
@RooJpaActiveRecord
public class Team {

    @NotNull
    @Size(max = 80)
    private String name;

    @NotNull
    private String mission;

    @ElementCollection
    private List<TeamMember> teamMembers;
}

@RooJavaBean
@RooToString
@Embeddable
public class TeamMember {

    @NotNull
    @Size(max = 40)
    private String name;
}

Did I mention - Git branches are cheap?

Git is great for things like this - since it keeps versions and branches within your .git database directory, you can branch and merge at will, and then push the repository updates when you are ready.

PrintView Printer Friendly Version

EmailEmail Article to Friend

Reader Comments

There are no comments for this journal entry. To create a new comment, use the form below.

PostPost a New Comment

Enter your information below to add a new comment.

My response is on my own website »
Author Email (optional):
Author URL (optional):
Post:
 
Some HTML allowed: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <code> <em> <i> <strike> <strong>