Introduction

• framework for web-development, spanning from the data to the interface (JSP)
• developed since 2001, currently version 0.7 (revision 2153)
• basic training takes 2h
• NGO BEST (Board of European Students of Technology)
• textual replacement for Lotus Notes
• BEST IT group:
  • approx. 20 amateur developers, high turnover of members (10 new / year)
  • loosely coupled group (spread everywhere over Europe)

Makumba Philosophy

• be easy to learn, yet powerful for advanced users
• have easily readable and understandable code
• be simple to configure
• query-centric: SQL-like language, easy to read
• HTML as a simple language, familiar to many
• scale for large applications and large developement teams
  • Karamba! webapp: 2800+ JSPs, 200+ Java Business Logic files, 100+ data structures
  • doubled its size since 2002

Makumba Data Definitions (MDDs)

• each data definition represents one object
• MDDs are simple propery files
• few types (char, int, real, text, intEnum, binary) easy to learn
• relational types: ptr (pointer), set
• any language employing these database-like concepts (e.g. Hibernate mappings) can provide data definitions

Example:

  # Person - simple data for a person
  name = char[50]          ;Name
  surname = char[50]       ;Surname or last name
  gender = int{"Male" = 10, "Female" = 20} ; Gender
  brother = ptr Person ;the brother
  cars = set Car       ;Cars of this person

  # Car - simple data for a car
  name = char[50]    ;Name of the car
  colour = int{"Green" = 10, "Blue" = 20, "Red" = 30}

Displaying data: Makumba List

• query-based iteration
• can be nested and optimal queries will be composed
• query languages: OQL (Object Query Language), HQL (Hibernate Query Language)

Example:

  <mak:list from="Person p" where="p.age > 18">
    <em><mak:value expr="p.name" /> <mak:value expr="p.surname" /></em><br/>
    Cars: 
    <mak:list from="p.cars c" separator=", "><mak:value expr="c.name" /></mak:list><br/>
  </mak:list>

Result:

John Doe
Cars: Audi TT, Audi A6
Foo Bar
Cars: BMW Z3

Entering data: Makumba Forms (1/2)

• build on familiarity with HTML forms
• aim: getting things into the database with a minimum of efforts
• automatically generates the HTML necessary to display the form, depending on the data type of the fields

Example:

  <mak:newForm type="Person" action="listPersons.jsp">
    Name:    <mak:input field="name"/><br />
    Surname: <mak:input field="surname"/><br />
    Gender:  <mak:input field="gender"/><br />
    <br />
    <input type="submit" value="Create" />
  </mak:newForm>

Result:

Name:    
Surname: 
Gender:  MaleFemale

Entering data: Makumba Forms (2/2)

• combined list and forms
• can be nested

Example:

<mak:form action="editPersonCars.jsp">
  <mak:list from="Person p">
    <em><mak:value expr="p.name"/> <mak:value expr="p.surname"/></em><br/>
    <mak:list from="p.cars c">
      <mak:editForm object="c">
        Car ${mak:count()} name: <mak:input field="name" /><br/>
      </mak:editForm>
    </mak:list>
  </mak:list><br/>
  <input type="submit" value="Change">
</mak:form>

Result:

John Doe

Car 1 name:
Car 2 name:
Foo Bar
Car 1 name:

Makumba Developer Support

• Source Viewer
• Code Generator
• Query interface

Makumba Business Logics & Controller

Business Logics:

• based on java
• at the moment, "per page" business logic
• makes it possible to perform validation, response actions (e.g. e-mail sending) and advanced processing before and after an object is created/modified/deleted

Controller:

• "weak" MVC
• scales for large applications with a distributed development team (! Struts, template engines...)
• ensures independence between developers (possibility to easily divide tasks between members)

Future

• Per-object Business Logic
• Hibernate / POJO-based business logic
• Query Fragments
  
  query functions in the MDD:
  

  cars = set Car ;cars of this person
  numberOfRedCars() = count(c) from cars c where c.color = 'Red'
  

  used in the JSP:
  

  <mak:list from="Person p">
    <mak:value expr="p.name" /> - <mak:value expr="p.numberOfRedCars()" />
  </mak:list>
  

• Per-object authorisation

  canEdit(Person p)= p.age > 18 AND p.numberOfCars() > 0
  

• further integration with Hibernate and Struts