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    Oracle Application Express 3.2: The Essentials and More
    Oracle Application Express 3.2: The Essentials and More
    Oracle Application Express 3.2: The Essentials and More
    Ebook1,377 pages8 hours

    Oracle Application Express 3.2: The Essentials and More

    By Arie Geller and Matthew Lyon

    ()

    Read preview

    About this ebook

    In Detail

    Developing data-centric web applications can be a real challenge as it is a multi-disciplinary process. There are many technologies involved in the client side (HTML, CSS, JavaScript, and so on); the interaction with the database, on the server side; the typeless nature of the web environment; and above all, the need to put it all together. This needs to be done in a manner that will allow the end users to do their job in the simplest and most efficient way, while enriching their user experience. How often have you wished that developing such applications could be uncomplicated and straightforward? This book will show you that it's possible, and teaches you how to do it, using Oracle Application Express (APEX).

    With this practical guide to APEX, you'll learn how to easily develop data-centric web applications for the Oracle environment. The book covers the development cycle of an APEX application, reviewing the major APEX principles and building blocks chapter by chapter. It starts with the basic skills you need to get going when developing with APEX. Later, you will learn advanced issues, such as how to build tailor-made forms and reports, using APEX APIs, AJAX, and so on. It not only deals with the "How" but also with the "Why", and before long you will be able to understand APEX concepts, and use them to expand and enhance the built-in features, wizards, and tools.

    The book starts with the design phase, including building the necessary database objects infrastructure; continues with ways to implement the application logic (on the server side) and the User Interface (on the client side), whilst showing you how to enhance your applications' features and functionality according to your specific needs; and it ends with application deployment.

    The book emphasizes and clearly documents areas such as Globalization, Localization, and developing multi-lingual applications, and includes a special discussion about Right-To-Left (RTL) support for APEX applications, documented here for the first time.

    Throughout the book, there are many screenshots and snippets of code, taken from working APEX applications. The book is accompanied by demo APEX applications that you can download and install in your APEX environment, thoroughly analyze, and learn from as you read the book.

    A practical tutorial for developing applications using Oracle Application Express

    Approach

    This book is a practical guide that not only shows you how to do things, but also makes you understand how things really work, so you'll be able to develop your own applications. It uses many screenshots, examples, and real-time "APEX code", some of which is documented for the first time.

    Who this book is for

    This book is for developers, in general, and web developers, in particular, who wish to learn how to develop data-centric web applications in the Oracle environment. It is also for novice APEX developers, who wish to learn how to use and best utilize the APEX environment, as well as for more experience APEX developers who wish to improve their knowledge and understanding of APEX and its capabilities, and learn from the experience of others.

    It assumes basic knowledge of HTML, SQL, and PL/SQL. Basic JavaScript understanding is an advantage, and in general can make your life much easier as an APEX developer.

    LanguageEnglish
    PublisherPackt Publishing
    Release dateJun 1, 2010
    ISBN9781847194534
    Oracle Application Express 3.2: The Essentials and More
    Author

    Arie Geller

    Arie Geller is an independent IT consultant, with more than 30 years of experience with systems analysis, software development, IT infrastructure, etc. He started to use HTML DB 1.6 (the former name of APEX) to develop data centric Web applications in the Oracle environment, and continue doing so, with all the following versions, until today. Arie has specialized in developing Right-To-Left-oriented applications, and he brings his expertise and experience in this field into the book. Arie is also an active member of the APEX community on OTN, where he assists other members and shares his knowledge and experience as much as he can.

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      Book preview

      Oracle Application Express 3.2 - Arie Geller

      Table of Contents

      Oracle Application Express 3.2

      Credits

      About the Authors

      About the Reviewers

      Preface

      What is the aim of the book

      Who this book is for

      What this book covers

      Standards and assumptions

      Conventions

      Reader feedback

      Customer support

      Errata

      Piracy

      Questions

      1. An Introduction to APEX

      Web-based

      Native Web based

      Data Centric

      A declarative development tool

      RAD tool

      Application Builder

      SQL Workshop

      Utilities

      Globalization, localization, and NLS

      APEX architecture

      Summary

      2. What we need to know to effectively use APEX

      SQL and PL/SQL

      HTML and CSS

      JavaScript

      HTML

      The DOM (Document Object Model)

      DOM walking

      DOM methods

      DOM events

      The APEX context

      CSS

      The cascading effect

      The style sheets

      CSS properties

      CSS selectors

      HTML tags selectors:

      Pseudo-class selectors:

      HTML ID selectors:

      Class selectors

      Compound (nested) class selectors:

      Contextual selectors:

      The !important keyword

      The APEX angle

      Where to store our external CSS file?

      How to load our CSS code?

      Globalization and NLS

      JavaScript

      JavaScript features

      Object-Oriented

      Case sensitive

      JavaScript variables

      JavaScript arrays

      JavaScript operators

      Blocks of code

      Conditional blocks of code:

      Repetitive (loop) blocks of code:

      JavaScript functions

      The APEX angle

      Where to store our external JavaScript file?

      How to load our external JavaScript file?

      Globalization and NLS

      PL/SQL and JavaScript (advanced)

      JavaScript and server-side resources (advanced)

      The APEX JavaScript API

      $x(pItemId)

      $v(pItemId)

      $s(pItemId, pValue)

      $x_UpTill(pItemId, tagName, className)

      $x_Show(pItemId) , $x_Hide(pItemId)

      redirect (location)

      Summary

      3. APEX Basic Concepts

      Session state

      Session state firing points

      Session state and the application page life cycle

      Session state and the page rendering phase

      Using computations in the page rendering phase

      Using processes in the page rendering phase

      Special session state processes

      Session state and the page processing phase

      Computations and processes in the page processing phase

      Manually saving to session state

      Using the APEX_UTIL.SET_SESSION_STATE API procedure

      Session state and AJAX

      Using the f?p URL notation

      Referencing persistence session state

      Session state and stored procedures

      Using the v() and nv() functions wisely

      Session state scope and persistence

      Reviewing session state from the application builder

      Substitution strings

      APEX engine built-in substitution strings

      Substitution strings that contain data

      Substitution strings that contain HTML code

      Application substitution strings

      Application or page items

      Referencing substitution strings

      Using the #ITEM# notation

      Using the &ITEM. notation

      Referencing substitution strings in SQL and PL/SQL code

      The bind variable notation

      The APEX built-in v() and nv() functions

      Shortcuts

      Defining a shortcut

      The name field

      The type field

      The shortcut field

      Shortcuts availability

      Themes and templates

      Themes

      Templates

      Page templates

      Region templates

      Reports templates

      Breadcrumbs templates

      List templates

      Calendar templates

      Label templates

      Button templates

      Popup List Of Values template

      Templates and the APEX upgrade process

      Theme, templates, and good practice

      The f?p URL notation

      The p segments

      1—App

      2—Page

      3—Session

      4—Request

      5—Debug

      6—CC (Clear Cache)

      7—itemName

      8 itemValue

      9—PR (Printer friendly)

      Item values including the colon character

      APEX multi-lingual support

      The APEX built-in translation mechanism

      Single language applications

      Single application with Multi-lingual user interface

      National Language Support (NLS) in this book

      Summary

      4. The Application Builder Basic Concepts and Building Blocks

      The APEX Workspace

      Start working with APEX

      Logging in to the APEX IDE

      The APEX IDE home page

      The APEX Application Builder

      The Application Builder home page

      The Import button

      The Create button

      The Application IDE home page

      The Pull Down menu section

      The application pages section

      The detailed list of application pages

      The Download link

      The Page component

      The Page Rendering column

      The Hide/Show icon bar

      The Page Processing column

      The Hide/Show icon bar

      The Shared Components column

      The Hide/Show icon bar

      The Action Bar

      Creating an application page

      Editing the Page Definition page

      The Page section

      A page region

      Creating a page region

      Editing a page region

      Region identification

      Caching

      Summary

      5. APEX Items

      Naming conventions and rules

      Oracle Identifiers naming rules

      Case sensitive APEX item names

      Application items

      Application items and security issues

      Referencing application items

      Application items and JavaScript

      Page items

      The Name section

      The Name field

      The Display As field

      The Displayed section

      The Sequence field

      The Region field

      The layout fields

      The Drag and drop wizard

      The Label section

      The Label field

      The Horizontal / Vertical Alignment field

      The Template field

      The HTML Table Cell Attributes field

      The Element section

      The item dimension fields

      The HTML Form Element Attributes field

      The Form Element Option Attributes field

      The Pre/Post Element Text fields

      The Source section

      The Source Used field

      Only when current value in session state is null

      Always, replacing any existing value in session state

      The Source Type field

      Maintain session state

      Source value or expression

      Post Calculation Computation

      Format Mask

      The Default section

      The List of Values section

      Static LOV

      Dynamic LOV

      Defines LOV

      LOV related wizards

      The Security section

      The Conditions section

      The Condition Type field

      The Expression 1 / Expression 2 fields

      The Read Only section

      The Help text section

      The Configuration section

      The Comments section

      APEX pre-defined item types

      Text based items

      Multi-option based items

      Special functionality items

      Creating APEX items programmatically

      Summary

      6. APEX Buttons

      Button styles

      HTML Button

      Image based button

      Template Driven button

      Button positioning

      Create new button(s)

      Button position

      Create a button in a region position

      Button attributes

      Image attributes or template (not for HTML)

      Display properties

      Position

      Sequence

      Branching (optional)

      Conditional display

      Create a button displayed among this region's items

      Edit a button

      The REQUEST feature

      The REQUEST scope

      Referencing REQUEST

      Condition by REQUEST

      Using JavaScript with among this region's items buttons

      Re-visit the Buttons section

      Summary

      7. APEX Computations

      Create a page level computation

      Compute item

      Sequence

      Computation point

      Page Rendering computation points

      Page Processing computation point

      Computation type

      Computation

      Condition

      Create an application level computation

      Computation item

      Frequency

      Edit computations

      Computations and Session State

      Summary

      8. APEX Validations

      Data validation

      How APEX validation works?

      Creating a new validation

      Validation level

      Create multiple not null validations

      Item

      Validation method

      SQL

      Exists

      Not Exists

      SQL Expression

      PL/SQL

      PL/SQL Expression

      PL/SQL Error

      Function Returning Boolean

      Function Returning Error Text

      Multi-lingual support for error messages

      Item Not Null

      Item string comparison

      Item specified is a valid date

      Regular Expression

      Sequence and Name

      Sequence and Validation Name

      Error Display Location

      On Error Page

      Inline

      Validation

      Conditions

      Page level validation

      Edit validations

      Client-side validation

      Implementing client-side validation

      Client-side versus server-side validations

      Summary

      9. APEX Processes

      Application Processes

      Creating a new Application Process

      Name

      Sequence

      Point

      Source

      Error message

      Conditionality

      Edit Application Processes

      Localization and Application Processes

      Page level processes

      Creating a new page level process

      Process Type

      PL/SQL

      Reset Pagination

      On Demand

      Session State

      Data manipulation

      Automatic Row Fetch

      Automatic Row Processing (DML)

      Multi Row Update, Multi Row Delete, and Add rows to tabular form

      Web Services

      Form Pagination

      Close pop-up window

      Edit page level process

      Source: Automatic Row Processing (DML)

      On Demand processes

      Summary

      10. APEX Branches

      Application flow

      Creating a new branch

      Branch point

      Branch type

      Branch to Function Returning a Page

      Branch to Function Returning a URL

      Branch to PL/SQL procedure

      Branch to page

      Branch to page accept processing (not common)

      Branch to Page Identified by Item (Use item name)

      Branch to page or URL

      Save state before branching

      Branches URL and JavaScript

      Branch to URL identified by item (Use item name)

      Sequence and branch conditioning

      Edit branch

      Other ways to control the application flow

      Branch with Buttons

      Branch with PL/SQL

      Branch with JavaScript

      Branch with an item

      Navigational aids

      Summary

      11. APEX SQL Workshop

      Navigating around the SQL workshop

      Object Browser

      Exploring the database with the Object Browser

      Creating new database objects

      UI defaults

      Creating a package

      SQL Commands

      The SQL Commands code area

      The SQL Commands results area (Display Pane)

      SQL Scripts

      Query Builder

      The Query Builder working area (Design Pane)

      The Query Builder results area (Output Pane)

      Summary

      12. APEX Forms

      Sources for creating a form

      Creating a new form

      The form primary key

      The form items

      The form DML options

      The form branches

      A new form has been created

      The Page Rendering phase

      The items section

      The Page Rendering Processes section

      The Page Processing phase

      The Validations section

      The Page Processing Processes section

      The Branches section

      Manually creating an APEX form

      Summary

      13. APEX Reports

      Report regions

      Creating a simple report using a wizard

      Start the report region wizard

      Region type

      Report implementation

      Display attributes

      SQL source

      Query Builder

      Report attributes

      Conditional display

      Wizard completion

      Modifying a report manually

      Editing a Region Definition

      The identification section

      The user interface section

      The source section

      The caching section

      The header and footer section

      Editing Report Attributes

      The column attributes section

      The layout and pagination section

      The messages section

      The report export section

      The break formatting section

      The external processing section

      Editing Column attributes

      The column definition section

      The column formatting section

      The tabular form element section

      The column link section

      Conditional display

      Editing print attributes

      The printing section

      The page attributes section

      The page header section

      The column heading section

      The report columns section

      The page footer section

      Enabling PDF printing

      Building a custom report row layout template

      Building a parameterized report

      Charts

      Summary

      14. Tabular Forms

      What is a Tabular Form?

      Using a wizard to create a Tabular Form

      Start the Report Region Wizard

      Region type

      Form implementation

      Identify Table/View Owner

      Identify Table/View Name

      Identify columns to display

      Identify Primary Key

      Primary key source

      Updateable columns

      Page and region attributes

      Button labels

      Branching

      Confirmation

      Wizard completion

      Show me the Tabular Form

      What does the Tabular Form wizard add to my page?

      Advanced note on the Update process

      How does the Tabular Form wizard organize the data on a page?

      The client side

      The server side

      Report regions revisited

      Validating the Tabular Form

      Enhancing Validation Errors Messages

      Changing the default error message phrase

      Add row number column

      Using Page Error for the Validation error message(s)

      Using JavaScript and AJAX

      Manually building a Tabular Form

      Displaying the Tabular Form

      APEX_ITEM API

      Rendering the Tabular Form

      Referencing and validating Tabular Form items

      Using checkboxes

      DML on the Tabular Form

      Delete

      Update

      Insert

      Summary

      15. Calendars

      Calendar region

      Using a wizard to create a calendar

      Start the calendar region wizard

      Region type

      Calendar implementation

      Region attributes

      Calendar source

      Define columns

      Viewing the calendar

      Modifying a calendar manually

      Region Definition

      Region Source

      Calendar Attributes

      The Calendar Display section

      The Display Attributes section

      The Column Link section

      The Day Link section

      Summary

      16. Interactive Reports

      Interactive Report Regions

      Select Columns

      Filter

      Sort

      Control break

      Highlight

      Compute

      Aggregate

      Chart

      Flashback

      Save report

      Reset

      Download

      Converting an Existing Report Region

      Create an Interactive Report using a wizard

      Start the Interactive Report Region Wizard

      Region Type

      Report Implementation

      Display attributes

      Source

      Conditional Display

      Wizard completion

      Manually modifying an Interactive Report

      Report Attributes

      Column Attributes

      Column Groups

      Default Report Settings

      Pagination

      Search Bar

      Download

      Link Column

      Advanced Attributes

      Column attributes

      Column Definition

      List of Values

      Column Link

      Linking to Interactive Reports

      Summary

      17. AJAX with APEX

      The AJAX technology

      The XMLHttpRequest object

      Communication

      Data format

      AJAX implementation in APEX

      AJAX support on the client side

      The htmldb_Get object

      1—obj

      2—flow

      3—req

      4—page

      5—instance

      6—proc

      7—queryString

      Code examples

      The htmldb_Get methods

      .Add(name,val)

      .AddParam(name,val)

      General remarks

      .get(mode, startTag, endTag)

      The mode parameter

      The startTag and endTag parameters

      Code examples

      Restrictions with AJAX pulling content

      Pulling report with pagination

      .GetAsync(pVar)

      The pVar function

      Namespace for the APEX AJAX framework

      AJAX support on the server side

      Application on-demand PL/SQL process

      Stored (packaged) procedure

      Handling errors in the AJAX process

      Debugging a failed AJAX process

      Examples of using AJAX in APEX

      Multiple calendars on a single application page

      The calendar main page (page xx)

      The 'Previous/Next Month' region

      The 'Main Calendar' region

      The small calendars page (page yy)

      Checkbox persistence in Tabular Forms (Reports)

      Report on CUSTOMERS

      The report SQL query

      The report headers

      The AJAX client-side JavaScript functions

      The updateCB() JavaScript function

      The toggleAllCB() JavaScript function

      The header_CB_Status() JavaScript function

      The AJAX server-side processes

      update_CB

      updateCB_all

      Summary

      18. Globalization and Localization With APEX Applications

      A brief introduction to Globalization and Localization

      Globalization

      Localization

      Native IDE support of multiple languages

      Loading another language into APEX IDE

      Unloading the APEX IDE translated language

      Loading another language into APEX Runtime Environment

      Multi-language support

      How do we start Globalization support?

      Setting the APEX application language

      Date format

      Using the APEX Date Picker

      Adding or editing Globalization

      Load Data—Localization

      Translating Text Messages

      The Text Messages translation wizard

      Manage the Text Messages repository

      Using APEX Shortcut with Text Messages

      Dynamic Translations

      Using the Dynamic Translations repository

      Using the APEX_LANG APIs

      APEX_LANG.MESSAGE

      APEX_LANG.LANG

      Multi-lingual applications

      The translation mechanism home page

      1—Application Language Mapping

      2—Seed and export

      3—Translating the text

      4—Import and publish the translation

      Editing the Translatable Text repository

      Running translated applications

      Deploying translated applications

      Summary

      19. Right-To-Left Support in APEX

      Why we need special Right-To-Left support

      Basic Right-To-Left scenarios

      Right-To-Left as a single language

      Right-To-Left as a translation language

      APEX templates with Right-To-Left support

      Page templates

      The Header section

      Right-To-Left as a single language

      Right-To-Left as a translation language

      The Body and Footer sections

      Tab attributes sections

      Button templates

      Popup List of Values Template

      All the other template types

      The APEX Shuttle item

      Labels and input fields alignment

      Date and time

      Summary

      20. Deploying APEX Applications

      What do we need to deploy?

      Supporting Objects

      Messages

      Prerequisites

      Substitutions

      Build Options

      Validations

      Create/Update a Validation

      Install

      Create Script

      Script Attributes

      Define Script

      Create Scripts to Install Files

      Upgrade

      Deinstallation

      Export

      Exporting an Application

      Exporting a page

      Exporting components

      Components

      Components by Page

      Application Attributes

      Build Option Status

      Export Components

      Importing an application

      Start the Import Wizard

      Specify File

      File Import Confirmation

      Install

      Supporting Objects installation

      Command line export utility

      Summary

      21. The APEX Runtime Environment

      What is the APEX Runtime Environment?

      Setting up a Runtime Environment

      Managing the APEX Runtime Environment

      Installing applications

      APEX_INSTANCE_ADMIN API

      Viewing APEX reports

      Oracle SQL Developer

      Summary

      22. Security

      APEX security features overview

      Authentication Schemes

      Adding an Authentication Scheme

      Creation method

      Selecting a pre-built Authentication Scheme

      Adding a login page

      Specifying LDAP settings

      Authentication Scheme name

      Changing the current Authentication Scheme

      Custom Authentication Scheme

      Authentication reports

      Authorization Schemes

      Create an Authorization Scheme

      Creation method

      Authorization Scheme details

      Assigning Authorization Scheme to pages, regions, and items

      Resetting Authorization Scheme results

      Authorization Reports

      Session state protection

      Security Attributes

      Authentication

      Authorization

      Database Schema

      Session Timeout

      Session State Protection

      Virtual Private Database

      Summary

      23. Application Conversion

      APEX application conversion

      Planning and understanding the application

      APEX Application Migrations

      Creating an APEX workspace

      Converting Microsoft Access applications

      Exporting Microsoft Access metadata

      Migrating the Access database to Oracle

      Creating a repository

      Capturing Microsoft Access exported XML

      Converting to an Oracle Model

      Generating schema

      Creating an Oracle database

      Creating a Migration Project

      The Migration Project page

      Generating the application

      Select Application Objects

      Page Definition

      User Interface

      Confirmation

      Converting Oracle Forms applications

      Converting Oracle Forms to XML

      Database

      APEX Migration Project

      Reviewing and editing application metadata

      Annotations

      Including objects in conversion

      Generating the application

      Application name

      Create Pages

      Page Definition

      User Interface

      Confirmation

      What's left to do?

      Summary

      24. APEX Best Practices

      Don't re-invent the wheel

      Be innovative when necessary

      Learn the APEX IDE

      The Drag and Drop Layout wizard

      The Action Bar

      The Page Definition view options

      Setting up workspaces

      Application ID

      Page numbering and page groups

      Use Oracle naming conventions

      Use bind variables

      Don't hardcode, use Substitution Strings

      Use PL/SQL packages

      Protect your business logic secrets

      Re-useable code

      Shared Components

      Page Zero

      Pre-defined and built-in resources

      User Interface Defaults

      Never change the provided APEX resources

      Themes and Templates

      JavaScript and CSS

      Never trust the end user

      Client-side validation

      Don't rely on database constraints

      Create your own restore point

      Multi-user environment

      Multi-lingual environment

      Team development

      Lock your pages

      Version control

      Document development standards

      Thou shall enter comments

      APEX views (APEX dictionary)

      APEX Application Reports

      APEX Runtime-only version

      Backup, backup, and more backup

      Summary

      A. APEX Installation, Upgrade, and Configuration Tips

      Obtaining APEX

      Reading the relevant documentation

      Back up your database and APEX applications

      Use AL32UTF8 in your DAD

      PL/SQL Web Toolkit

      EPG—Embbeded PL/SQL Gateway

      Enabling FTP on EPG

      Enabling remote access to EPG

      EPG versus OHS

      Utilizing static files caching

      Obfuscate your DAD file

      Upgrading an APEX Instance

      Copy the new images directory

      Themes and Templates in the Upgrade process

      Summary

      Index

      Oracle Application Express 3.2

      Arie Geller

      Matthew Lyon

      Oracle Application Express 3.2

      The Essentials and More

      Copyright © 2010 Packt Publishing

      All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

      Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the authors, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.

      Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.

      First published: June 2010

      Production Reference: 1250510

      Published by Packt Publishing Ltd. 32 Lincoln Road Olton Birmingham, B27 6PA, UK.

      ISBN 978-1-847194-52-7

      www.packtpub.com

      Cover Image by Vinayak Chittar (<vinayak.chittar@gmail.com>)

      Credits

      Authors

      Arie Geller

      Matthew Lyon

      Reviewers

      Ashish Agarwal

      Ben Burrell

      Katie McLaughlin

      Penny Cookson

      Acquisition Editor

      James Lumsden

      Development Editors

      Dhiraj Chandiramani

      Rakesh Shejwal

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      Project Coordinator

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      Proofreaders

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      Graphics

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      Cover Work

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      About the Authors

      Arie Geller is an independent IT consultant, with more than 30 years of experience with systems analysis, software development, IT infrastructure, etc. He started to use HTML DB 1.6 (the former name of APEX) to develop data centric Web applications in the Oracle environment, and continue doing so, with all the following versions, until today.

      Arie has specialized in developing Right-To-Left-oriented applications, and he brings his expertise and experience in this field into the book. Arie is also an active member of the APEX community on OTN, where he assists other members and shares his knowledge and experience as much as he can.

      I would like to thank my surrounding family for their great patient and support, and also to my friends and customers for their understanding, during the very demanding period of writing this book.

      I would also like to thank Joel Kallman and Scott Spadafore (RIP) from the APEX development team, for their invaluable help and insight on APEX, over the years.

      Matthew Lyon is a Senior Consultant at SRA Information Technology in Adelaide, South Australia. His involvement in enterprise software development extends across analysis, design, development, architecture, and project management, giving him a deep appreciation of the effective use of software technology. He has experience with a wide variety of technologies but has a passion for Oracle APEX and Java. Matthew runs APEX training courses for clients and is active in the Oracle community as a presenter and as a committee member of the South Australian Oracle User Group. Matthew has more than 10 years experience in software development and has been using APEX since HTMLDB version 1.6.

      I would like to thank my lovely wife Zoe and beautiful baby girl Rose for their help and support while writing this book.

      About the Reviewers

      Ashish Agarwal has the distinct privilege of being one of the less than a few hundred Oracle Certified Masters in the world (http://www.oracle.com/technology/ocm/aagarwal.html). He is also a certified Project Management Professional from PMI, USA & Oracle Certified Professional in Oracle 10g, 9i, 8i, and 8. With a total industry experience of more than 12 years in Information Technology Field, exhaustive experience and Knowledge in Managing Oracle Databases and Oracle Applications (ERP and CRM Suites), administration is his expertise. Participating in the design of Infrastructure Architecture for Oracle Products and managing data centre kind of environment with multiple databases and servers are some of his other experience areas.

      Ashish has worked with companies like Panasonic, Oracle, Sapient, and Mercer across the geographies of India, Singapore, Malaysia, Canada, and the UK, and is now currently running DBCON - a Database & Oracle APEX consulting company based in Singapore. DBCON leverages on the power of the Internet to provide live online training, application development, management and maintenance, support, and troubleshooting in Oracle technologies to anyone in the world. DBCON also leverages on the power of the Internet to engage the best people in their respective areas from across the globe.

      Attracted to Oracle Application Express because of its simplicity and productivity, Ashish regularly conducts live online training in Oracle Application Express through his company DBCON. Anyone from anywhere in the world can attend this training with just a PC and internet connection. To learn more about live online training in Oracle Application Express please visit http://www.dbcon.com or e-mail at .

      Ben Burell is an Oracle developer currently based in the Isle of Man. He is an active contributor to the Oracle APEX forum as 'Munky' and sporadically blogs about APEX related tips and tricks at http://munkyben.wordpress.com.

      He enjoys problem solving while listening to music, meaning that he quite enjoys his job!

      Katie McLaughlin is a software developer and consultant who has been working with Oracle Apex for many years, developing enterprise applications as well as for smaller business requirements. She currently works for an international software house, developing financial applications for some of the largest companies in the world.

      I'd like to thank my partner, Karl, for all his kindness and for bringing many a cup of tea during the time I worked on this book.

      Penny Cookson has been working with Oracle products since 1987. Penny is the Managing Director and Principal Consultant for SAGE Computing Services, an Australian company which specializes in providing Oracle education and consulting services. She has written and conducted training courses and provided expert advice in a wide range of products, including Application Express, and is a regular presenter at Oracle and User Group conferences. She was Oracle Magazine's Educator of the Year in 2004 and is an Oracle ACE.

      Preface

      Oracle Application Express — APEX for short, or by its former name, HTML DB, is a declarative, Web-based RAD (Rapid Application Development) tool. APEX runs inside an Oracle database, tightly integrated with its internal resources, and utilize them optimally. Using a Web browser, it allows us to develop, test, and deploy a Web based, data-centric application in a declarative manner, but on the same time it doesn't limit our abilities to manually enter specific and tailored code, both on the client and server side, that will answer our most specific needs and demands.

      Developing data centric Web applications can be a real challenge as it's a multi-disciplinary process. There are many technologies involved in the client side (HTML, CSS, JavaScript, etc.); the interaction with the database, in the server side; the typless nature of the Web environment; and above all, the need to put it all together, in a manner that will allow the end users to do their job, in the simplest and most efficient way, while enriching their user experience. If you are working in the Oracle environment, APEX can be your best solution.

      What is the aim of the book

      With this book, you'll learn how to easily develop data centric Web applications for the Oracle environment, using the APEX RAD tool.

      This book is not a recipes book, although it includes many working examples. You will learn to understand the basic principles behind the APEX building blocks, and how they operate. It will allow you to take advantage of existing APEX recipes but more importantly to create your own.

      The book covers the development cycle of an APEX application. It starts with the design phase, including building your necessary database objects infrastructure; continue with ways to implement the application logic (on the server side) and the User Interface (on the client side), whilst showing you how to enhance your applications features and functionality, according to your specific needs; and it ends with application deployment.

      The book includes dedicated chapters that deal with the Globalization and Localization aspects of developing APEX applications, with dedicated chapter for developing Right-To-Left oriented applications.

      Who this book is for

      This book is for developers, in general, and web developers, in particular, who wish to learn how to develop data-centric web applications in the Oracle environment. It is also for novice APEX developers, who wish to learn how to use and best utilize the APEX environment, as well as for more experience APEX developers who wish to improve their knowledge and understanding of APEX and its capabilities and learn from the experiences of others.

      Developers who work in a multi-lingual environment, in general, and in a Right-To-Left environment, in particular, will be most beneficial from the dedicated chapters on these subjects, which include issues that we believe are documented for the first time.

      The book assumes basic knowledge of HTML, SQL, and PL/SQL. Basic JavaScript understanding is an advantage, and in general, can make your life much easier as an APEX developer. The book includes a dedicated chapter which gives a general review of these issues.

      What this book covers

      Chapter 1, An Introduction to APEX gives an introduction of APEX architecture and technology, while explains some of the above-mentioned terms in the APEX context.

      Chapter 2, What we need to know to effectively use APEX reviews. Some of the basic skills we should have in order to better utilize the Web development aspects of APEX. It talks about HTML, the DOM, CSS, and JavaScript.

      Chapter 3, APEX Basic Concepts discusses some of the major APEX concepts and explains how they can help us in our developmental efforts.

      Chapter 4, The Application Builder Basic Concepts and Building Blocks explains the major building blocks of the APEX application, and how to create them using the APEX Application Builder.

      Chapter 5, APEX Items discusses the major building blocks of the application page — the application items. We'll review application items and page items and learn how they can serve us in our applications.

      Chapter 6, APEX Buttons explains different types of buttons that a developer can place on an APEX page, creating/editing them, assigning attributes and using the REQUEST feature

      Chapter 7, APEX Computations reviews the computation mechanism and sees how we can use it in our applications.

      Chapter 8, APEX Validations discusses APEX validations, which help us to maintain the integrity and consistency of our data by making sure that only correct and consistent data will be used and saved into the database.

      Chapter 9, APEX Processes reviews the main concepts of APEX processes and how they can help us to implement our application logic. It includes discussions on application level processes (including on-demand processes), page level processes, and the various types and options APEX provides us with to implement them.

      Chapter 10, APEX Branches discusses APEX Branches, which are responsible for the flow of the application.

      Chapter 11, APEX SQL Workshop reviews some APEX IDE built-in utilities that will help us define our application database infrastructure, either declaratively or by using DDL commands and scripts.

      Chapter 12, APEX Forms reviews the various sources that we can use to create an APEX form. How to use the APEX Create Form wizard to generate a new form and manually create an APEX form.

      Chapter 13, APEX Reports discusses how we can create and modify reports in APEX applications.

      Chapter 14, Tabular Forms describe the APEX tabular form concept, with a very detailed discussion on how to generate one using an APEX wizard, or in more complex scenarios, doing it manually, using specific APEX APIs.

      Chapter 15, Calendars looks at how we can use calendar components in our applications.

      Chapter 16, Interactive Reports looks at how we can use Interactive Reports in our applications.

      Chapter 17, AJAX with APEX looks at how we can utilize the APEX AJAX framework, both on the client and server side, to integrate and support this important technology in our APEX applications.

      Chapter 18, Globalization and Localization With APEX Applications deals with the Globalization and Localization aspects of APEX applications. It include detailed discussion about the APEX built-in translation mechanism and sees how we can develop multi-lingual APEX applications.

      Chapter 19, Right-To-Left Support in APEX review the specific actions we need to take in order to generate and support APEX Right-To-Left applications.

      Chapter 20, Deploying APEX Applications discuss the means APEX provides us to deploy our developed applications.

      Chapter 21, The APEX Runtime Environment explains what the APEX Runtime Environment is all about and how we can manage it.

      Chapter 22, Security looks at APEX Security and how it can be used in our applications.

      Chapter 23, Application Conversion looks at how we can convert Microsoft Access and Oracle Forms applications to APEX.

      Chapter 24, APEX Best Practices looks at the best practices for developing APEX applications.

      Appendix deals with APEX installation, upgradation, and configuration issues.

      Standards and assumptions

      This book assumes basic knowledge in the main technologies and programming languages that we are using while working in APEX. These include, for the client side, HTML/XHTML, CSS, and JavaScript; and for the server side SQL and PL/SQL.

      You can practice developing APEX application using the Oracle hosted site on apex.oracle.com. APEX is also included in the free ORACLE XE database version, which can be downloaded from the Oracle OTN site (http://otn.oracle.com). You can also download the latest version of APEX, and use it to upgrade the built-in version in the Oracle XE.

      Conventions

      In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.

      Code words in text are shown as follows: On a page level, we define the

      A block of code is set as follows:

      . . .

      stylesheet type=text/css href=myCSS.css />

      . . .

      When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

      select * from emp t

       

      where t.deptno = v('P1_DEPTNO')

      and t.hiredate = (select max(hiredate) hiredate

      from emp t1

      where deptno = v('P1_DEPTNO'))

      New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: APEX includes some wizards and tools, such as the Wizard Report and Query Builder.

      Note

      Warnings or important notes appear in a box like this.

      Tip

      Tips and tricks appear like this.

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      Chapter 1. An Introduction to APEX

      Oracle Application Express — APEX for short, or by its former name HTML DB is a declarative, Web-based RAD (Rapid Application development) tool. It is used to develop native Web-based, data centric applications.

      Let's clarify some of these terms, and understand what they mean in the APEX context.

      Web-based

      The term Web-based appears in the description of both the development tool and its product — the APEX application. We are using a Web browser to both develop and run our applications. The advantages are obvious. Web browsers are installed, almost by default, on most of the workstations we are using, independently of the workstation hardware or operating system. It means that on the client side, we don't need anything else to start developing with APEX, or to run APEX applications. Moreover, it means very easy access to our applications, both internally — using Intranet — or externally, using the Internet If we add all the modern smart phones and other PDAs on the market today, which include built-in Web browsers, we'll come to the conclusion that the range of options to access our APEX applications is very wide.

      Another important advantage when using a Web browser is the ability to free us from hardware and local operating system dependencies. As the APEX Application Builder actually generates HTML code, we (as developers) don't have to worry about the hardware specifications, or the local operating system our end users will be using, to run our APEX application. As long as they have access to an HTML supporting Web browser, we are covered.

      However, Web based application development can also be a drawback. Unfortunately, not all Web browser manufacturers have fully adopted all the international standards in this field. As a result, there are cases in which different Web browsers will display the same code page differently. The variety of Web browsers in the market today, like Internet Explorer, Firefox, Chrome, Opera and Safari, just to name a few, support and implement HTML, XHTML, CSS and JavaScript versions and levels, in different ways and styles. There are known cases where even the same Web browser brand, but in different versions, or across local operating systems, delivers different results with the same code. We need to be aware of this, and take actions to resolve it — if we want to ensure cross-browser compatibility code for our applications (which will apply to greater numbers of potential users). Sometimes we need to take hard decisions and waive the support of certain web browsers in order to keep our code simple and maintainable.

      A list of supported Web browsers can be found in the APEX release notes. For version 3.2, which is the latest APEX version at the time of writing this book, it can be found at http://download.oracle.com/docs/cd/E14373_01/relnotes.32/e13365/toc.htm#BGBCEGBI

      Native Web based

      APEX, in all its previous forms, was always designed to operate in the Web environment. The final product of the APEX Application Builder is HTML code that can be run directly on any Web browser that supports the HTML 4.0 and above standard. APEX Application Builder also incorporates special features into generated applications, as a direct result of operating in the Web environment. Further on, we will discuss APEX architecture and its main features, but for now we will mention session state and Optimistic Locking, as distinguished Web environment features which help us overcome the stateless nature of this environment.

      The APEX Application Builder fully supports CSS (Cascading Style Sheets) and JavaScript, as integrated components of APEX applications. That includes built-in CSS files as part of a wider page layout and format mechanism, which we'll address later in the book, and a JavaScript library. The JavaScript library also includes, among a variety of general and APEX related functions, an AJAX (Asynchronous JavaScript and XML) framework. This allows even novice developers to utilize this advanced technology, and produce high quality applications, compatible with the latest trends in the market like Web 2.0, etc.

      Data Centric

      APEX was designed to produce applications that store, retrieve, manipulate, and display data, from Oracle Databases. This means that if your application's main logic doesn't revolve around data manipulation, it may be that APEX is not your optimal application development tool. However, if data manipulation is at the heart of your application, APEX could be your best bet.

      APEX is actually a collection of PL/SQL packages, which live inside the Oracle database. It means that APEX automatically inherits all the outstanding features, often mentioned with regards to the Oracle database environment: high performance, robustness, reliability, enhanced security, scalability, and more. In addition, APEX can natively utilize the very rich SQL and PL/SQL environment, including the built-in packages that the Oracle database has to offer, and use them to manipulate the data in the optimal ways a RDBMS can offer.

      Moreover, APEX can utilize special functionality features that are included in the various database versions and editions, like Oracle XML DB, Oracle Text, and Oracle Multimedia.

      Another advantage in this context is that, like the client side which relies on Web browsers to gain hardware independence, (alongside operating system independence), the APEX engine relies on the database platform for the same purpose. As long as we have a proper running version of an Oracle database, starting with Oracle database 9.2.0.3 and above (including the free version, Oracle XE), we can ignore the hardware and operating systems aspects of the server.

      A declarative development tool

      APEX is a declarative tool. It means that we, as developers, concentrate more on the What needs to be done, and less on the How to do it. Think, for example, about SQL. In a SELECT statement, when we are using the ORDER BY clause, we are actually telling the database what we need — a sorted data result set, but we don't tell it how to actually do the sorting. In fact, the entire SELECT statement, just like SQL itself, is a declarative statement. In APEX, we are telling the Application builder that we need to lay out an HTML item on the page, or retrieve certain records from the database, and the APEX engine generates the proper code for doing that, both on the server side and the client side.

      Working declaratively in APEX means that we are not generating traditional (3 GL) program code. Instead, we are working with a series of wizards and property sheets, which allows us to define all the metadata we need in order to generate an application page's code. APEX includes sets of pre-defined wizards, supported HTML objects, supported database objects and data types, page rendering options and procedures, after submit processes and DML options, navigation and branching options, and more. We can use all of these to declare our application page's forms, reports, charts, etc., with their layouts and application/business logic. The APEX engine translates it all into an HTML code for the client side, and SQL and PL/SQL code for the server side. Whenever the predefined options don't give us the exact solution we need, APEX allows us to use our own SQL and PL/SQL code for the server side, and HTML/XHTML, CSS, and JavaScript code, for the client side. As mentioned before, it also allows us the use of AJAX technology, within a built-in framework, to query the server side, while running on the client side without submitting the page.

      RAD tool

      APEX provides us with a full development environment, allowing us to develop, test, and deploy our applications. APEX includes three modules: Application Builder, SQL Workshop, and Utilities.

      Application Builder

      The Application Builder allows us to develop and test our applications, without leaving the development environment. While working in the Application Builder, it automatically adds a dedicated developer toolbar to every page in our application, making it very easy to toggle between the running page and its code within the Application Builder. The developer toolbar also provides the developer with more options to assist in the development process, like checking session state, running in debug mode, etc. Moreover, the Application Builder allows us to manage, monitor, and control all the application's shared components, supporting objects, and deployment scripts. In addition, the Application Builder includes tools for exporting and importing applications and application components.

      Note

      Some of these terms might be unfamiliar to you at this stage, but don't be alarmed as we'll cover them all further down this book.

      SQL Workshop

      The SQL Workshop includes a series of tools which allow us to create, manage, and inspect our application data infrastructure. This including wizards to create and manipulate database objects, scripts and queries, and the SQL Commands facility, which allows us to run SQL and PL/SQL code in the context of APEX. This can be very useful, as some of the APEX features and APIs are not available outside the APEX context (e.g. SQL*Plus) for security reasons.

      Utilities

      The Utilities module includes a number of tools to help us manage the APEX development-surrounding environment, especially regarding the database. It includes tools for the import and export of data into and out of the database, the APEX data dictionary, and several database monitoring and reporting tools.

      The APEX environment also includes a special administration module, which allows us to define the APEX working environment, developers, and users.

      All these modules include declarative, wizard-based tools, which makes the application development cycle a very rapid one. These development environment allows us to quickly define a prototype of our application, and then expand it with all the finer details.

      Globalization, localization, and NLS

      APEX was designed with globalization, localization, and NLS (National Language Support) in mind. To begin with, the APEX interface is translated into nine languages, other than English. The languages are German, Spanish, French, Italian, Japanese, Korean, Brazilian Portuguese, Simplified Chinese, and Traditional Chinese.

      APEX can utilize all the globalization, localization, and NLS features that the Oracle database has to offer, and add some of its own. The Application Builder Shared Components module includes a Globalization section, which allows us to define relevant parameters for globalization, localization, and NLS. It also includes a wizard to guide us through the process of translating our entire application into secondary languages.

      APEX takes into account the client side NLS settings when dealing with the import and export of data into and out of the database. It also takes into account the database NLS settings, in order to properly sort data, display dates, number format (e.g. decimal point or comma) and the local currency, among others.

      APEX supports the XLIFF (XML Localization Interchange File Format) standard, which allows us to translate an entire APEX application into any language we need, without re-writing the application code. APEX provides a built-in mechanism to simultaneously run the same application in multi language User Interfaces, giving us several options to determine the application language, including the option of matching the APEX application language to the end user's browser language preferences. Moreover, if we need to support a language which is not included in the native supported languages list, this mechanism will allow us to specifically translate the built-in APEX engine strings and messages into that language, allowing us to develop and support APEX application in any language that our database can support.

      Tip

      Since version 2.0, the client side communicates with the server side, using the AL32UTF8 character set, regardless of the database character set. Due to some of the advanced technologies APEX is using (like AJAX), this setting is mandatory. If you are going to work in a multi-language environment, it would be optimal to set your database character set to AL32UFT8. This will ensure a true multi-language environment, while eliminating the need to employ any character set conversions between the client and the server. Oracle is advising users to use AL32UTF8 as their default choice for the database character set.

      Throughout this book, we will devote special attention to globalization, localization, and NLS issues in the APEX environment, including RTL (Right-To-Left) support examples.

      APEX architecture

      The core of APEX is a collection of PL/SQL packages, written using the PL/SQL Web Toolkit, and several hundred database tables, in which all the metadata regarding developed applications are stored.

      The PL/SQL Web Toolkit is a collection of Oracle supplied database packages, which allow us to produce Web page code, directly in the database, using PL/SQL stored procedures. During run-time, and in real-time, the APEX engine queries the metadata tables and retrieves all the relevant information for a specific application page. Next, it uses the PL/SQL Web Toolkit to generate the application page's HTML code. This page's code also includes the proper linkage to the CSS and JavaScript resources that support proper page functionality, layout, and styles. Some internal tests run by the APEX development team, showed that the APEX engine performs all the real-time rendering processes, with an average overhead of less than 0.04 seconds per page. Pretty impressive in my opinion, and the APEX engine includes a server side caching mechanism, that can help us reduce that further.

      It is important to understand that although the final product of APEX Application Builder is an HTML page code, no static files with any related HTML file extensions, are stored on the server. Each page is created upon demand a specific URI request. That, of course, gives us considerable flexibility with constructing the pages, e.g. the same page can be displayed somewhat differently for various users, or include conditioned components, depending on the user's security privileges, or role in the company, etc.

      So, on one side we have the APEX engine, a collection of PL/SQL packages, running inside an Oracle database, and on the other side we have the application user, using a Web browser. How can we connect, and communicate between the sides? As we are in a Web environment, we are going to use the HTTP protocol, implemented in two technologies.

      The first way is by using the Oracle HTTP Server (OHS) technology. OHS is based on the well-known (open source) Apache HTTP server, in its 1.3 or 2.0 versions. What interests us, for the APEX environment, is the Oracle plug-in module for this HTTP server, called mod_plsql.

      OHS, with the mod_plsql module, is located between the client's Web browser and the Oracle database server. The mod_plsql module communicates with the database by mapping the Web browser request into PL/SQL stored procedures in the database.

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