Application Developer's Guide

Application Development with the Liquid Data API

Types of Application Development

WebLogic Workshop Development

EJB Development

JSP Tag Library Development

About Liquid Data Queries

Stored Queries

Ad Hoc Queries

Parameterized Queries

Components of the Liquid Data Query API

Packages

Query Execution EJB

Query Parameters

Query Attributes

Query Results

Types of Java Clients

Using Liquid Data Controls to Develop Workshop Applications

WebLogic Workshop and Liquid Data

Liquid Data Control

XMLBean Generation

Use With Page Flow, Web Services, Business Processes

Liquid Data Control JCX File

Design View

Source View

Schema Project Location

Running Ad-Hoc Queries through the Liquid Data Control

Creating Liquid Data Controls

General Steps to Create a Liquid Data Control

Step 1: Create a Project in an Application

Step 2: Start the Liquid Data Server, If It is Not Already Running

Step 3: Create a Folder in a Project

Step 4: Create the Liquid Data Control

Step 5: Enter Connection Information to the Liquid Data Server

Step 6: Select Queries to Add to the Control

To Create a Liquid Data Control in a Web Project

To Create a Liquid Data Control in a Web Service Project

To Add a Liquid Data Control to an Existing Web Service File

To Create a Test Web Service From a Liquid Data Control

Modifying Existing Liquid Data Controls

To Change the Query Associated With a Single Control Method

To Add a New Method to a Control

To Invoke the Query Wizard to Modify an Existing Control

Updating an Existing Control if Schemas Change

Using NetUI to Display Liquid Data Results

Generating a Page Flow From a Control

To Generate a Page Flow From a Control

Adding a Liquid Data Control to an Existing Page Flow

Adding XMLBean Variables to the Page Flow

To Add a Variable to a Page Flow

To Initialize the Variable in the Page Flow

Displaying Query Results in a Table or List

To Add a Repeater to a JSP File

To Add a Nested Level to an Existing Repeater

To Add Code to Handle Null Values

Security Considerations With Liquid Data Controls

Security Credentials Used to Create Liquid Data Control

Testing Controls With the Run-As Property in the JWS File

Trusted Domains

To Configure Trusted Domains

Moving Your Liquid Data Control Applications to Production

Development to Production Lifecycle Architecture

Packaging Liquid Data JAR Files in Application .ear Files

Liquid Data ldcontrol.properties File

Steps For Deploying to Production

Step 1: Generate Enterprise Application Archive (.ear) in Workshop

Step 2: Merge ldcontrol.properties File entries to Production Server

Step 3: Deploy Enterprise Application Archive (.ear) on Production Server

Invoking Queries in EJB Clients

Step 1: Connect to the Liquid Data Server

Step 2: Specify Query Parameters

Step 3: Execute the Query

Step 4: Process the Results of the Query

Invoking Queries in JSP Clients

About the Liquid Data Tag Library

Scope of the Liquid Data Tag Library

Location of the Liquid Data Tag Library

Making the Tag Library Accessible to a Web Application

Copy the LDS-taglib.jar File to the WEB-INF/lib Directory

Add the <taglib> Entry to the web.xml File

Tags in the Liquid Data Tag Library

query Tag

param Tag

Processing Steps

Step 1: Add the Tag Library to your Web Application

Step 2: Reference the Liquid Data Tag Library

Step 3: Connect to the Liquid Data Server

Step 4: Specify Query Parameters

Step 5: Execute the Query

Executing Stored Queries

Executing Ad Hoc Queries

Handling Exceptions

Step 6: Process the Query Results

Invoking Queries in Web Service Clients

Finding the WSDL URL for Generated Web Services

Invoking Web Services Programmatically

Invoking Queries in WebLogic Integration Business Processes

Liquid Data and WebLogic Integration Business Processes

Setting Up a Liquid Data Query in a Business Process

Create the Liquid Data Control

Adding a Liquid Data Control to a JPD File

Setting Up the Control in the Business Process

Invoking Queries in BEA WebLogic Portal Applications

Invoking Liquid Data Queries as EJB Clients

Invoking Liquid Data Queries as JSP Clients

Using Custom Functions

About Custom Functions

Defining Custom Functions

Step 1: Write the Custom Function Implementation in Java

Rules for Writing Custom Function Implementations

Correspondence Between XML and Java Data Types

Step 2: Create the Custom Functions Library Definition File

Contents of a CFLD File

Structure of a CFLD File

Elements and Attributes in a CFLD File

Step 3: Register the Custom Function in the Administration Console

Examples of Custom Functions

Example That Uses Simple Types

Implementation of Custom Functions for Simple Types

CFLD File That Declares Custom Functions for Simple Types

Query That Uses the Custom Functions for Simple Types

Example That Uses Complex Types

Implementation of a Custom Function for a Complex Type

CFLD File That Declares the Custom Function for a Complex Type

Query That Uses the Custom Function for a Complex Type

Setting Complex Parameter Types

Architecture of Complex Parameter Types

Sample Complex Parameter Type Code

Sample Query

Sample Code

Compiling and Running the Sample Code

Using the Cache Purging APIs

The com.bea.ldi.cache.ejb Package

Security Issues When Using the Cache APIs

Writing Java Code to Purge Cache Entries

Enable Caching in Liquid Data

Import the Liquid Data Packages

Lookup the EJB Home in the JNDI Tree

Sample Cache Purging Code