The HTMLDB_APPLICATION package exposes several global variables used internally by the APEX engine.

• g_user:  This is the ID of the currently logged in user.

• g_flow_id:  This is the ID of the currently running application.

•  g_flow_step_id:  This is the page ID for the currently running application page.

• g_flow_owner:  This is the parsing schema for the current application.

• g_request:  This is the most recent REQUEST.  Requests are set by buttons in APEX.

The HTMLDB_APPLICATION package also exposes a global array which references values from certain page items.  The HTMLDB_ITEM package can be used to create items on an application page.  This means the developer creates them programmatically during page rendering instead of creating the page item with a wizard.  When items are created like this, they are provided a numeric value.  APEX then references the page item in an array.  Up to 50 items can be created using the HTMLDB_ITEM package and still be allowed to reference them using HTMLDB_APPLICATION package.  An example of this was provided during the checkbox explanation in an earlier chapter of this book.  There, the htmldb_item.checkbox procedure was used to add checkboxes to a report.  The arrays in the htmldb_application package were then used to reference the checkbox during page processing.

For the checkboxes shown in Figure 10.3, the HTML code that was rendered by using the htmldb_item.checkbox procedure looks like the following:

<input type="checkbox" name="f10" value="1" CHECKED />
<input type="checkbox" name="f10" value="2" CHECKED />
<input type="checkbox" name="f10" value="3" />
<input type="checkbox" name="f10" value="4" CHECKED />
<input type="checkbox" name="f10" value="5" />

When the page is submitted, only the checkboxes which are checked will appear in the arrays of the htmldb_application package.  For the example above, there will be three array elements in the array named g_f10.  Programmatically, it is possible to loop through the array in a page processing process and update the data in the database.  The following code shows an example of how the code to loop through the htmldb_application.g_f10 array would look:

begin
  for i in 1..htmldb_application.g_f10.count loop
    update class
    set    available_flag = 'Y'
    where  class_id = htmldb_application.g_f10(i);
  end loop;
end;

While looping through the array and using the sample checkboxes from above, the values one, two, and four would appear in the array.

The above book excerpt is from:

Easy HTML-DB Oracle Application Express

Create Dynamic Web Pages with OAE

ISBN 0-9761573-1-4   

Michael Cunningham & Kent Crotty

http://www.rampant-books.com/book_2005_2_html_db.htm