My First Building Block

Presented By Tracy Engwirda 28 September, 2005

Overview

• Background • Planning – UI Integration – Which APIs • Package Structure • Manifest Structure • Security Framework • UI Taglibs • Building Blocks Manager • .. and more

Terminology

• Building Blocks Program – All development and integration with Blackboard products • Building Blocks Framework – The set of patterns and objects that allow interaction with all of Blackboard’s products • Building Blocks API – The Java and .NET interfaces • Building Blocks Manager – The management interface for Building Blocks • Building Block – An application that relies on the Building Blocks API • Blackboard Enabled – A quality assurance and testing program for Building Blocks

Terminology

• Building Block Types – Plug-in • Stand alone • Communicate only with Learning System – Bridge • Communicates with external server(s) and Learning System • Will not function without external server

Planning

• What are you project goals?

• What are the application requirements?

• How are you going to build your application?

– JSP? Servlet? Web Service?

• Where are you going to “hook” your application?

• Which APIs are you going to use?

Planning

• Where are you going to hook your application into Blackboard?

UI Entry Points

• New Course Tool • New Course Communication Tool • New Control Panel Tool • New System Admin Tool • New Portal Module • New Content Type • New User Tool

Entry Points

• Programmatic Entry Points – Specified in bb-manifest.xml

• Manual Entry Points – System Administrator created

Course Tool

Course ID is passed to page

Course Communication Tool

Course ID is passed to page

Course Control Panel

Course ID is passed to page

System Admin Panel

Nothing passed to page

Content Type

Course ID and Container ID are passed to page

Portal Module

module view.jsp admin.jsp Nothing is passed to page

User Tool

Nothing passed to page

Custom Tab

• System admin can change the location of a tab to point to a Building Block

Custom Course Link

• System admin or course instructor change add a Building Block to the course navigation area

Hidden Link

• A page does not need to be in the manifest in order to be loaded.

Planning

• Which APIs are you going to use?

API Capabilities

• Building Blocks APIs – Announcement (read and write) – Calendar (read and write) – Content (read and write) – Gradebook (read and write) – Session (read and write) – File system (read and write) – *User (read) – *Course (read) – *Membership (read) – .. And Many, many more!

API Capabilities

• How to write to User/Course/Membership?

 Event APIs • Event APIs use a similar data model to the Building Block APIs but has a different security model. Data object naming conventions match IMS structure of snapshot data.

API Capabilities

• Event APIs – Person (User) – Group (Course / Organization) – Membership – Catalog Category – Catalog Link – Data Source Key

Planning

• Installation

Installation

• Only system administrators can install • No restart required with Bb 6 • Must confirm Building Block permissions • Often requires configuration • Installation is through the Building Blocks Manager

Building Block Manager

• Heart of the Blackboard Platform • Controls security, permissions, and availability • Manages the “hook points” within the UI • Handles deployment

Building Block Manager

Building Blocks Manager API Wrappers & Convenience Methods Data Integrity Enforcement Blackboard Platform (LS/TS/CP) DB File System Persistence Plugin Security Session TagLib (UI)

Building Block Manager

Structure of Building Blocks

Building Block = Webapp

• A Building Block is a Java Web Application (webapp) with one extra file • The extra file is bb-manifest.xml

Directory Layout

Shared via web Hidden from web

Package Format

• A webapp is a zip file with a specific directory structure • WinZip, PkZip, Java’s Jar utility, or Ant will all create the correct package • Even though it

is

a zip file, the extension does not matter (.zip, .war, .bb will all work)

WEB-INF

• Hidden from web • Contents – web.xml

– bb-manifest.xml

– Config directory – Classes directory – Lib directory

Config Directory

• Hidden from web • Only accessible by the Building Block • Can contain anything – One option for storing your application data.

• No size limit

Custom Code and Libraries

• Classes – Stored in WEB-INF\classes • Jars – Stored in WEB-INF\lib – Automatically on classpath via custom classloader

Manifest Structure

• bb-manifest.xml

– Set of directives the developer provides • Building Blocks Configuration • Application Definitions – Content Handlers – UI Links – Portal Modules • Security Declarations • Let’s Take a Look…

bb-manifest.xml File

bb-manifest.xml File

bb-manifest.xml File

Link Checker tool installed with the Link Checker Plugin

bb-manifest.xml File

Link Checker tool installed with the Link Checker Plugin

bb-manifest.xml File

Link Checker tool installed with the Link Checker Plugin

Security Framework

• Security must be explicitly declared in the bb-manifest.xml file.

• XML Format corresponds closely with the format for Standard Java policy files • Security will be enforced by the JVM

UI Taglibs

• XML style tags that can be placed on a jsp page.

• Blackboard supplies two sets of taglibs – bbUI for making pages fit in with the product – bbData for giving pages context and virtual installation information • Specify your own in web.xml

More information

• Building Blocks Website http://www.blackboard.com/developers/ – Building Blocks Catalog – Software Development Kit (SDK) • Blackboard Developer Network (BbDN) http://behind.blackboard.com/ – Learning System Developer License – Communities, Knowledge Base, Code Snippets, White Papers, Beta Software • Other Community Resources – Open Source User Group and BBUG forums http://www.bb-opensource.org/

Why Start from Scratch?

• Start with a sample Building Block • Reuse existing code • Customize to meet your needs

Enough of the theory!

Let’s take a look at some real code…

Questions?