Built-in Substitution Strings

APP_ALIAS

APP_ALIAS is an alphanumeric name for the current application. APP_ALIAS is different from the APP_ID in that the APP_ID must be unique over all workspaces (or database user accounts) and all applications hosted in one database. In contrast, APP_ALIAS must be unique within a workspace. For example, by using the same APP_ALIAS you can create the application, ABC, in two different database user accounts. You can use APP_ALIAS almost anywhere APP_ID can be used. For example, f?p syntax can use an APP_ALIAS or an application ID as demonstrated in this example:

f?p=ABC:1:&SESSION.

This example runs application ABC, page 1 using the current session.

Table: APP_ALIAS Syntax describes the supported syntax for referencing APP_ALIAS.

The following is an HTML example:

Click me to go to page 1 <a href="f?p=&APP_ALIAS.:1:&SESSION."> of the current application</a>

APP_ID

APP_ID identifies the application ID of the currently executing application. Table: APP_ID Syntax describes the supported syntax for referencing APP_ID.

The following is an example of a substitution string reference:

f?p=&APP_ID.:40:&SESSION.

APP_IMAGES

Use this substitution string to reference uploaded images, JavaScript, and cascading style sheets that are specific to a given application and are not shared over many applications. If you upload a file and make it specific to an application, then you must use this substitution string, or bind variable. Table: APP_IMAGES Syntax describes the supported syntax for referencing APP_IMAGES.

APP_PAGE_ID

APP_PAGE_ID is the current application ID. For example, if your application was on page 3, then the result would be 3. Using this syntax is useful when writing application components that need to work generically in multiple applications. Table: APP_PAGE_ID Syntax describes the supported syntax for referencing APP_PAGE_ID.

The following is an example of a substitution string reference:

f?p=&APP_ID.:&APP_PAGE_ID.:&SESSION.

APP_SESSION

APP_SESSION is one of the most commonly used built-in substitution strings. You can use this substitution string to create hypertext links between application pages that maintain a session state by passing the session number. Table: APP_SESSION Syntax describes the supported syntax for referencing APP_SESSION.

Consider the following examples:

• From within an HTML region:

  <a href="f?p=100:5:&SESSION.">click me</a> 
  
  

• Using PL/SQL:

  htf.anchor('f?p=100:5:'||V('SESSION'),'click me');
  
  

• Using a SQL query:

  SELECT htf.anchor('f?p=100:5:'||:app_session,'clickme') FROM DUAL;
  
  

APP_UNIQUE_PAGE_ID

APP_UNIQUE_PAGE_ID is an integer generated from an Oracle sequence which is unique for each page view. This number is used by applications to prevent duplicate page submissions and can be used for other purposes. For example, if you want to make a unique URL to avoid browser caching issues, you can embed this number in the request or debug column in calls to the f procedure. Table: APP_UNIQUE_PAGE_ID Syntax describes the supported syntax for referencing APP_UNIQUE_PAGE_ID.

The following is an HTML example:

SELECT 'f?p=100:1:'||:APP_SESSION||':'||:APP_UNIQUE_PAGE_ID||
    ':::P1_EMPNO:'||empno,
   ename,
    job
FROM emp

Note the use of the APP_UNIQUE_PAGE_ID in the request column. This makes this URL unique and may avoid excessive browser caching problems.

APP_USER

APP_USER is the current user running the application. Depending upon your authentication model, the value of the user is set differently. If the application is running using database authentication, then the value of the user is the same as the database pseudo column USER. If the application uses an authentication scheme that requires the user to authenticate, the value of APP_USER is set by the authentication scheme, usually to the user name used during authentication. Table: APP_USER Syntax describes the supported syntax for referencing APP_USER.

Consider the following examples:

• From within an HTML region:

  Hello you are logged in as &USER.
  
  

• Using PL/SQL:

  htp.p('Hello you are logged in as'||V('USER')); 
  
  

• As a bind variable:

  SELECT * FROM some_table WHERE user_id = :app_user
  
  

  
  

  See Also: "Authentication" for information about the Public User attribute

  
  

AUTHENTICATED_URL_PREFIX

This application-level attribute identifies a valid authenticated prefix (that is, a logged in URL prefix). You can use a relative path or a full path beginning with http. This item is useful if your application can be run in both authenticated (logged in) and public (not logged in) modes. You can use AUTHENTICATED_URL_PREFIX to construct a link to an authenticated page. This item is most useful when using basic database authentication because changes to the URL can require authentication. Table: AUTHENTICATED_URL_PREFIX Syntax describes the supported syntax for referencing AUTHENTICATED_URL_PREFIX.

BROWSER_LANGUAGE

BROWSER_LANGUAGE refers to the Web browser's current language preference. Table: BROWSER_LANGUAGE Syntax describes the spported syntax for referencing BROWSER_LANGUAGE.

CURRENT_PARENT_TAB_TEXT

CURRENT_PARENT_TAB_TEXT is most useful in page templates, but is only relevant for applications that use two-level tabs (that is, parent and standard tabs). Use this string to reference the parent tab label. This substitution string enables you to repeat the currently selected parent tab within the page template. Table: CURRENT_PARENT_TAB_TEXT Syntax describes the supported syntax for referencing CURRENT_PARENT_TAB_TEXT.

DEBUG

Valid values for the DEBUG flag are Yes or No. Turning debug on shows details about application processing. If you write your own custom code, you may want to generate debug information only if the debug mode is set to Yes. Table: DEBUG Syntax describes the supported syntax for referencing DEBUG.

The following is an example of a substitution string reference that preserves the current value of DEBUG:

f?p=100:1:&SESSION.::&DEBUG

HOME_LINK

HOME_LINK is the home page of an application. The Application Express engine will redirect to this location if no page is given and if no alternative page is dictated by the authentication scheme's logic. You define the Home Link on the Application Attributes page.

Table: HOME_LINK Syntax describes the supported syntax for referencing HOME_LINK.

LOGIN_URL

Use LOGIN_URL to display a link to a login page for users that are not currently logged in. Table: LOGIN_URL Syntax describes the supported syntax for LOGIN_URL.

IMAGE_PREFIX

The value of IMAGE_PREFIX determines the virtual path the Web server uses to point to the images directory distributed with Oracle Application Express. If you want to reference uploaded images, use WORKSPACE_IMAGES and APP_IMAGES. Table: IMAGE_PREFIX Syntax describes the supported syntax for referencing IMAGE_PREFIX.

Application Express SCHEMA OWNER

If you are generating calls to applications from within your PL/SQL code, you may need to reference the owner of the Oracle Application Express schema. The following describes the correct syntax for a direct PL/SQL reference:

HTMLDB_APPLICATION.G_FLOW_SCHEMA_OWNER

You may also use #FLOW_OWNER# to reference this value in SQL queries and PL/SQL (for example, in a region or a process).

PRINTER_FRIENDLY

The value of PRINTER_FRIENDLY determines if the Application Express engine is running in print view mode. This setting can be referenced in conditions to eliminate elements not desired in a printed document from a page. Table: PRINTER_FRIENDLY Syntax describes the supported syntax for referencing PRINTER_FRIENDLY.

LOGOUT_URL

LOGOUT_URL is an application-level attribute used to identify the logout URL. This is a URL that navigates the user to a logout page or optionally directly logs out a user. To create a logout navigation bar entry, add a trailing period to &LOGOUT_URL (&LOGOUT_URL.). If you are coding a page template, use #LOGOUT_URL#. Table: LOGOUT_URL Syntax describes the supported syntax for referencing LOGOUT_URL.

PROXY_SERVER

PROXY_SERVER is an application attribute. The attribute may be used by regions whose source comes from a URL. The following is the correct syntax for a direct PL/SQL reference used when you are writing PL/SQL to access remote Web servers from within the database (for example, when using the utl_http package shipped with the database).

HTMLDB_APPLICATION.G_PROXY_SERVER

PUBLIC_URL_PREFIX

PUBLIC_URL_PREFIX is an application-level attribute that identifies a URL to toggle out of a logged in mode to a public view. Table: PUBLIC_URL_PREFIX Syntax describes the supported syntax for referencing PUBLIC_URL_PREFIX.

REQUEST

Each application button sets the value of REQUEST to the name of the button or to the request value attribute associated with the button. This enables accept processing to reference the name of the button when a user clicks it. In the f?p syntax, REQUEST may be set using the fourth argument.

f?p=100:1:&SESSION.:GO

IF V ('REQUEST') = 'GO' THEN
   htp.p('hello');
END IF;

SQLERRM

SQLERRM is a template substitution only available in the Applications Region Error Message. The following describes the correct syntax for a region template substitution reference:

#SQLERRM#

SYSDATE_YYYYMMDD

SYSDATE_YYYYMMDD represents the current date on the database server, with the YYYYMMDD format mask applied. You may use this value instead of repeated calls to the SYSDATE() function. The following list describes the supported syntax for referencing SYSDATE_YYYYMMDD.

• Bind variable

  :SYSDATE_YYYYMMDD
  
  

• PL/SQL

  V('SYSDATE_YYYYMMDD')
  
  

• Direct PL/SQL

  HTMLDB_APPLICATION.G_SYSDATE (DATE DATATYPE)
  
  

WORKSPACE_IMAGES

Use this substitution string to reference uploaded images, JavaScript, and cascading style sheets that are shared over many applications within a workspace (or database user account). Table: WORKSPACE_IMAGES Syntax describes the supported syntax for referencing WORKSPACE_IMAGES.