2. How it works?

Main engine is in masser.fcgi file, which must be installed in such a place to be accessible by web server. Applications themselves can be placed anywhere, but I recommend to store them outside of DOCUMENT_ROOT of web server not to be viewed using web server due to error or bad configuration.

It's fast-cgi application, so main program is started by web server (at start or at first request - regarding configuration).

2.1 Startup initialization

Immediately after start program will read configuration:

• if environment variable MASSER_CONFIG is set, configuration file is read from file set in this variable
• otherwise configuration is read from masser.conf file
• if this setting is not absolute path, masser is trying to find the file in these directories:
  • current directory
  • directory /usr/etc
  • directory /etc

2.2 Request processing

When a request is received, system processes parameters, first of all from request URL, then from request itself (GET or POST type).

1. after URL part leading to script masser one or two (or three in debug mode) parts are processed:
   • if the first argument is _source, program will show source code of the page
   • first part is supposed to be application code
   • second part is assumed to be (list of) page(s) requested to be shown
   Examples:

   /path_to_masser/masser/TEST

   will show (default) page of TEST application

   /path_to_masser/masser/_source/TEST/page1

   will show source code of page page1 from TEST application

2. next following variables are worked out (if they are not set from previous point):

   APP

   application name (uppercase is recommended), default is APP

   PG

   list of pages to be shown (comma separated), default is default

   OP

   list of operations to be done (comma separated), default is none (empty)

   LANG

   language code, default is CZ

   SCH

   schema code, to be used by application

   SID

   Session Identification, to be used by application

Next application is initialized (if not used before):

• read and parse configuration according to masser settings, filename is assumed to be in this form: application name converted to lowercase with .conf suffix
• database connect initialization (regarding configuration)
• read and parse files with labels in languages according to configuration, filenames are assumed in <app>_lang.<lang_code> form (app always in lowercase) and masser tries to find it for every path from masser.conf and app.conf this way:
  • directory / app_name / lang / file
  • directory / app_name / file
  • directory / lang / file
  • directory / file
• application initialization: masser tries to find file <app>.init (app converted to lowercase) like this:
  • directory / app_name / init / file
  • directory / app_name / file
  • directory / init / file
  • directory / file
  If this file is found, it's compiled and run only once (for every masser instance).

  This is not true for debug mode, in this mode init action is run every request.

  This code is intended to actions to be performed only once in "application life" (for example read some specific configuration, setting some special database parameters etc.). Persistent variable %p can be used - read more in some next chapter.

Action or page is processed this way:

• compilation if not compiled yet

  always in debug mode

• check or connect required databases
• prepare SQL statements if they are not prepared yet

  always in debug mode

• set correct values to %txt hash (according to LANG variable)
• write source (compiled) code, if write_code_dir is set
• set persistent hash %p values
• run the code
• check pending transactions, write error if there are any and rollback them (regard pending_transaction_rollback setting)