There are many ways to implement a Web-enabled Oracle database using complex tools such as
XML and PHP. However, these are not easy tools for deploying complex Oracle Web systems,
and Oracle Application Express (HTML-DB) opens up a whole new world for Rapid Application
Development (RAD).
This book excerpt provides step-by-step examples for getting started building Web-enabled applications.
Oracle Application Express (Apex, or HTML-DB) is Oracle's latest tool for fast deployment of Web-based Oracle
systems, and this excerpt will get you started, fast.
This is an excerpt from the bestselling book Easy HTML-DB Oracle Application Express:
Create Dynamic Web Pages with OAE by Michael Cunningham and Kent Crotty. Click here to download the full chapter.
Introduction to Apex (HTML-DB)
This chapter serves two main purposes. The first is to introduce the HTML DB development
environment, and the second is to provide a reference for topics that are not specifically
mentioned in other chapters.
The Application Builder is complex, and this book will not cover it all. The book is written for
the beginning to intermediate-level HTML DB developer, so the most common things any user
should know when starting out will be covered.
Instead of taking up space in the individual chapters describing the HTML DB pages used to edit
the attributes of various components, they will be included in this chapter. When applicable,
more detailed explanations will be included in the other chapters.
Access to the Application Builder is gained from the Workspace home page. While on the
workspace home page, click on the Application Builder icon. This will bring up the Application
Builder home page.
Editing an application
From the Application Builder home page, click on the Conference RSVP application. This will
bring up the Application's home page.
There are several options available from the Application's home page. The Pages region shows a
list of the pages in the application as well as some key attributes of each page, such as page id, the
last time and by whom it was updated, and whether the page is locked for development. The
application can be run by clicking on the Run Application icon or run a single page by clicking on
the run stoplight icon.
Run Application
This icon can be used to run the application just as if it were being entered in the browser as a
URL. This simulates what a visitor to the web application would encounter upon entering the
application.
Edit Attributes
This is used to modify global Application Attributes and is described in greater detail in the
Application Attributes section later in this chapter.
Shared Components
Shared Components are parts of an application intended for use on many pages of an application.
They are reusable components. Many of the shared components can participate in what is called
Publish and Subscribe. For example, a List of Values (LOV) such as Products could be defined
in one application and published to other applications. If the LOV were to be modified, the
changes can be published to all the subscribing applications. There is also more detail for this
option later in the Shared Components section.
Export/Import
This function is used to export the entire application making it easy to deploy to another HTML-
DB database, or to export various pieces of the application such as Themes, Pages and User
Interface Defaults.
Standard attributes
The Application Attributes are where the global properties are set for the application. Navigate
to the Edit Application Attributes page by clicking on the down arrow in the Edit Attributes icon
and then click on the Edit Definition menu item. The standard attributes are explained in the
following sections.
Name
This is where the name of the application is set. It is also the name displayed in the Application
Builder home page.
Application Alias
The text entered here can be used in the URL to the application. The application alias can be
used in lieu of the application id. For example: if the application id is 102 as in the Conference
RSVP application, the application alias can be set to HELLOWORLD. Either of the following
can be used on the URL's to get to the application.
http://localhost:7777/pls/hdb20/f?p=102
http://localhost:7777/pls/hdb20/f?p=helloworld
NOTE: Use the Application Alias cautiously. These should be unique in the HTML DB engine. If the same
alias name is used more than once, it may confuse the HTML DB engine.
Version
The version field provides a place to set a version that can be used in page templates to indicate
the version on every page of the application if the user chooses. To add the version to a page
template, use the #APP_VERSION# substitution string in the templates.
Image Prefix
This is set to /i/ by default and represents the same setting as is in the dads.conf file as presented
in the section of this book on Database Access Descriptor (DAD). The value here must be the
same as in the DAD file.
Logging
This allows the activity to be recorded in activity logs. Each page view will be logged allowing the
workspace administrators to monitor the application activity. The activity reports will be covered
in the chapter on advanced HTML DB administration.
Parsing Schema
The parsing schema is very important to the application. All SQL statements and PL/SQL are
executed as a specific database user known as the parsing schema. This is also the schema that
will own the tables, indexes, PL/SQL, etc. that will be created through the SQL Workshop.
Although this can be modified for the application, EASYHDB will be used for the parsing
schema throughout the book. The EASYHDB parsing schema was created when the easy
workspace was created earlier in this book.
Status
This option is used to set the current status and availability of the application. This can be handy
when in a development mode for an application or when it is necessary to make an application
unavailable during maintenance.
Click here to read the rest of this chapter.
