Databases Reference
In-Depth Information
fetch is compared with the checksum of the displayed columns in the database. If the checksums match,
the update is allowed to go through. APEX also provides the same automatic protection of lost updates
for tabular forms.
Application Extensibility
APEX developers have significant declarative control of user interface. The primary control is templates.
Templates provide the HTML content for pages and page components. Templates are organized into
themes. You can use themes supplied as part of Oracle Application Express, you can create your own
themes, or you can import themes developed by others. When this doesn't provide what you need to get
the look or functionalty you're after, you have the following choices:
•
Create custom user interface templates.
•
Generate your own static HTML.
•
Generate dynamic HTML using PL/SQL.
•
Use plug-ins.
Customizing User Interface Templates
Templates are used to define the look, feel, and some of the functionality for page, region, item label, list,
breadcrumb, report, calendar and button components with Oracle Application Express. Each theme
contains several variations and alterantive templates of each type. You can create new templates or edit
exiting templates to achive a specific user interface. Figure 12-10 shows a button template. The button
template references the
#LABEL#
and
#LINK#
substitution strings. When buttons are created,
corresponding properties of the button are substituted. This makes the button template generic.
Figure 12-10
. APEX button template definition
Page templates are more powerful and more complex than button templates, but the functionality is
implemented in the same way. Structured content is used to replace substitution strings in reusable
components. An easy way to create a new template is to simply copy an existing template and customize
it.
