"page.access" trigger

Description

page.access trigger function is optional. if it is needed, must be in Code Behind File.

Whenever a Form File is requested, page.access function is called before procession file request. If the function does not exist, this means that requested file is public and all requests are granted. If page.access trigger function exists and;

• returns true, end users have been granted to access the page.

• returns false, the request has been refused.

Since it runs before page processing starts, page.access trigger function has the following restrictions:

• HTML elements defined in Form File (like data/control blocks, data lists) are not available/accessible in the trigger function code.

• Functions defined in Code Behind File are not available/accessible also.

What can be done in page.access trigger function:

• For authentication: Executing SQL statement in order to get user credentials from database tables.

• For authorization: Executing SQL statement in order to get user privileges.

• Logging: Executing SQL statement in order to insert/update log tables.

• Setting/getting session variables.

• Reading/writing files on disk.

Be careful: Usage of the page.access trigger function in "log on pages" must not block to accessing that page. In other words, the trigger function for log on page must always return true if exists. Otherwise nobody authenticate themselves to the application.

Declaration

bool page.access();

Example

bool page.access() {
    return :Session.authenticated;
}

See also