1. Aaron Zeckoski azeckoski@gmail.com
Sakai Tool Naming Tips
Aaron Zeckoski

2. Sakai tool environment
Many tools exist in a typical Sakai installation
As a developer, you have to be careful when working in a large scale environment
The primary issue is with naming collisions
Some names must be unique in the Sakai instance (not used by any other installed tools)
Tools have many interconnections and use a custom request cycle so some programming practices must be followed

3. Namespace collisions
Most namespace collisions will cause an error to occur on tomcat startup
Typically you will see that part of the spring tree died and therefore all spring beans are destroyed
Sometimes Sakai will still load but the offending tool will not
Tip: Watch tomcat logs when starting up new tools
URL:

4. Sakai tool xml file naming
<?xml version="1.0" encoding="UTF-8"?>
<registration>
<tool id="sakai.tasklist"
title="Programmer's Cafe - Task List"
description="Programmer's Cafe - Task List">
<category name="course" />
<category name="project" />
</tool>
</registration>
The tool id (e.g. sakai.tasklist) in the tool xml file must be unique
Typical id is sakai.toolname
Tool xml file located in tool/src/webapp/tools/
Typical filename is sakai.toolname.xml

5. Sakai project.xml naming
<?xml version="1.0" encoding="UTF-8"?>
<project>
<pomVersion>3</pomVersion>
<extend>../../master/project.xml</extend>
<name>Programmer's Cafe - Task List</name>
<groupId>sakaiproject</groupId>
<id>sakai-tasklist-tool</id>
<currentVersion>${sakai.version}</currentVersion>
...
The id (e.g. sakai-tasklist-tool) in each project.xml file must be unique
Typical id is sakai-toolname-location
Maven project.xml files are located throughout a typical Sakai app

6. Spring bean naming
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN"
"
<beans>
<bean id="org.sakaiproject.crudplus.logic.CrudPlusLogic"
class="org.sakaiproject.crudplus.logic.impl.CrudPlusLogicImpl"
init-method="init">
</beans>
The id (e.g. org.sakaiproject.logic.CrudPlusLogic) of each bean in components.xml must be unique
Convention for the id is to use the fully qualified classpath of the interface for the class
component.xml must be located in impl/pack/src/webapp/WEB-INF/

7. Database table naming
Database table names have to be unique since Sakai shares a common schema (or database)
Convention is to prefix the table name with the tool name (e.g. TOOLNAME_TABLE)
Good names:
SAM_ANSWER, EVAL_ANSWER, GB_GRADES
Bad names:
ANSWER, GRADE, CONFIG

8. Hibernate HBM files
All Hibernate HBM files have to have unique names since Sakai uses one common Hibernate SessionFactory
Convention is to prefix the hbm filename with the tool name (e.g. ToolnameItem.hbm.xml)
Good names:
EvalAnswer.hbm.xml, TasklistTask.hbm.xml
Bad names:
Answer.hbm.xml, Task.hbm.xml, Item.hbm.xml

9. Hibernate Persistent Classnames
All Hibernate persistent classes must have unique classnames (this does not include the fully qualified classpath)
Convention is to prefix the class name with the tool name (e.g. ToolnameItem.java)
Good:
EvalAnswer.java, TasklistTask.java
Bad:
Answer.java, Task.java

10. web.xml servlet name
<servlet>
<servlet-name>sakai.tasklist</servlet-name>
<servlet-class>org.sakaiproject.tool.tasklist.TasklistTool</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
The servlet-name in the web.xml file must match the tool id from the tool xml file
web.xml is located in tool/src/webapp/WEB-INF
If this does not match you will get an uninformative NPE (Null Pointer Exception) in the tomcat log and the tool will fail to load

11. Questions?