4 APEX_APPLICATION

Referencing Arrays

Items are typically HTML form elements such as text fields, select lists, and check boxes. When you create a new form item using a wizard, the wizard uses a standard naming format. The naming format provides a handle so you can retrieve the value of the item later on.

If you need to create your own items, you can access them after a page is submitted by referencing APEX_APPLICATION.G_F01 to APEX_APPLICATION.G_F50 arrays. You can create your own HTML form fields by providing the input parameters using the format F01, F02, F03 and so on. You can create up to 50 input parameters ranging from F01 to F50, for example:

<INPUT TYPE="text" NAME="F01" SIZE="32" MAXLENGTH="32" VALUE="some value">
 
<TEXTAREA NAME="F02" ROWS=4 COLS=90 WRAP="VIRTUAL">this is the example of a text area.</TEXTAREA>
 
<SELECT NAME="F03" SIZE="1">
<OPTION VALUE="abc">abc
<OPTION VALUE="123">123
</SELECT> 

Because the F01 to F50 input items are declared as PL/SQL arrays, you can have multiple items named the same value. For example:

<INPUT TYPE="text" NAME="F01" SIZE="32" MAXLENGTH="32" VALUE="array element 1">
<INPUT TYPE="text" NAME="F01" SIZE="32" MAXLENGTH="32" VALUE="array element 2">
<INPUT TYPE="text" NAME="F01" SIZE="32" MAXLENGTH="32" VALUE="array element 3">

Note that following PL/SQL code produces the same HTML as show in the previous example.

FOR i IN 1..3 LOOP
APEX_ITEM.TEXT(P_IDX        => 1,
   p_value      =>'array element '||i ,
   p_size       =>32,
   p_maxlength  =>32);
END LOOP;

Referencing Values Within an On Submit Process

You can reference the values posted by an HTML form using the PL/SQL variable APEX_APPLICATION.G_F01 to APEX_APPLICATION.G_F50. Because this element is an array, you can reference values directly, for example:

FOR i IN 1..APEX_APPLICATION.G_F01.COUNT LOOP 
    htp.p('element '||I||' has a value of '||APEX_APPLICATION.G_F01(i)); 
END LOOP;

Note that check boxes displayed using APEX_ITEM.CHECKBOX will only contain values in the APEX_APPLICATION arrays for those rows which are checked. Unlike other items (TEXT, TEXTAREA, and DATE_POPUP) which can contain an entry in the corresponding APEX_APPLICATION array for every row submitted, a check box will only have an entry in the APEX_APPLICATION array if it is selected.

Converting an Array to a Single Value

You can also use Oracle Application Express public utility functions to convert an array into a single value. The resulting string value is a colon-separated list of the array element values. For example:

htp.p(APEX_UTIL.TABLE_TO_STRING(APEX_APPLICATION.G_F01));

This function enables you to reference G_F01 to G_F50 values in an application process that performs actions on data. The following sample process demonstrates how values are inserted into a table:

INSERT INTO my_table (my_column) VALUES 
APEX_UTIL.TABLE_TO_STRING(APEX_APPLICATION.G_F01)

HELP Procedure

This function outputs page and item level help text as formatted HTML and can be used to customize how help information is displayed in your application.

Syntax

APEX_APPLICATION.HELP (
    p_request        IN VARCHAR2 DEFAULT NULL,
    p_flow_id        IN VARCHAR2 DEFAULT NULL,
    p_flow_step_id   IN VARCHAR2 DEFAULT NULL,
    p_show_item_help IN VARCHAR2 DEFAULT 'YES',
    p_show_regions   IN VARCHAR2 DEFAULT 'YES',
    p_before_page_html     IN VARCHAR2 DEFAULT '<p>',
    p_after_page_html      IN VARCHAR2 DEFAULT NULL,
    p_before_region_html   IN VARCHAR2 DEFAULT NULL,
    p_after_region_html    IN VARCHAR2 DEFAULT '</td></tr></table></p>',
    p_before_prompt_html   IN VARCHAR2 DEFAULT '<p><b>',
    p_after_prompt_html    IN VARCHAR2 DEFAULT '</b></p>:&nbsp;',
    p_before_item_html     IN VARCHAR2 DEFAULT NULL,
    p_after_item_html      IN VARCHAR2 DEFAULT NULL);

Parameters

Table 4-2 describes the parameters available in the HELP procedure.

Example

The following example shows how to use the APEX_APPLICATION.HELP procedure to customize how help information is displayed.

In this example, the p_flow_step_id parameter is set to :REQUEST, which means that a page ID specified in the REQUEST section of the URL will be used to control which page's help information to display (see note after example for full details on how this can be achieved).

Also, the help display has been customized so that the region sub-header now has a different color (through the p_before_region_html parameter) and also the ':' has been removed that appeared by default after every item prompt (through the p_after_prompt_html parameter).

APEX_APPLICATION.HELP(
    p_flow_id => :APP_ID,
    p_flow_step_id => :REQUEST,
    p_before_region_html => '<p><br/><table bgcolor="#A3BED8" width="100%"><tr><td><b>',
    p_after_prompt_html  => '</b></p>&nbsp;&nbsp;');

In order to implement this type of call in your application, you can do the following:

1. Create a page that will be your application help page.

2. Create a region of type 'PL/SQL Dynamic Content' and add the APEX_APPLICATION.HELP call as PL/SQL Source.

3. Then you can add a 'Navigation Bar' link to this page, ensuring that the REQUEST value set in the link is &APP_PAGE_ID.