File/program/modules/crew/crew_install.php

Description

/program/modules/crew/crew_install.php - installer of the crew module

This file contains the crew module installer. The interface consists of these functions:

    crew_install(&$messages,$module_id) crew_upgrade(&$messages,$module_id) crew_uninstall(&$messages,$module_id) crew_demodata(&$messages,$module_id,&$config,$manifest)

These functions can be called from the main installer and/or admin.php.

Note You cannot be sure about the environment from which these routines are called. If the caller is the Install Wizard, you do not have all subroutines available. However, it IS possible to manipulate the database via the db_*() routines and/or the global $DB object. Therefore you have to keep the install routine extremly simple. You also have no option to interact with the user; the install has to be a silent install; you can only indicate success (TRUE) or failure (FALSE) and maybe an error message in $messages[] but that's it. Good luck.

Functions
crew_demodata (line 179)

add demonstration data to the system

this routine goes through the motions to install a (demo) workshop. However, since configuration of the required websocket server is non-trivial, the demo is not complete. It does show that the module actually exists.

Note If the module is installed via the Install Wizard, this routine is called. However, if a module is installed as an additional module after installation, the {$mode}_demodata() routine is never called. This is because the only time you know that demodata is installed is when the Install Wizard runs. If we're called from admin.php, the webmaster may have already deleted existing (core) demodata so you never can be sure what to expect. To put it another way: it is hard to re-construct $config when we're NOT the Instal Wizard.

  • return: TRUE on success + output via $messages, FALSE otherwise
bool crew_demodata (array &$messages, int $module_id, array &$config, array $manifest)
  • array &$messages: collects the (error) messages
  • int $module_id: the key for this module in the modules table
  • array &$config: pertinent data for the new website + demodata foundation
  • array $manifest: a copy from the manifest for this module
crew_install (line 63)

install the module

this routine installs the module. For this module there are a few properties that need to be stored in the main modules_properties table. The specific table for this module is already created based on the tabledefs); see install/crew_tabledefs.php.

Note that the record for this module is already created in the modules table; the pkey is $module_id.

  • return: TRUE on success + output via $messages, FALSE otherwise
bool crew_install (array &$messages, int $module_id)
  • array &$messages: collects the (error) messages
  • int $module_id: the key for this module in the modules table
crew_uninstall (line 151)

uninstall the module

this is a hook for future extensions of Website@School. For now we simply return success. Any real code could look like this: DELETE FROM workshops; to delete all existing data (but who would want that). For now this is simply a nop.

Note that bluntly deleting from the workshops table might lead to nodes without a valid module. The better way to do it would be something like this:

    SELECT count(node_id) AS number_of_nodes FROM workshops; if ($number_of_nodes > 0) then     $messages[] = 'There are still $number_of_nodes nodes with a workshop';     return FALSE;
which in fact means that the table should already be empty before we can empty it. Oh well...

  • return: TRUE on success + output via $messages, FALSE otherwise
bool crew_uninstall (array &$messages, int $module_id)
  • array &$messages: collects the (error) messages
  • int $module_id: the key for this module in the modules table
crew_upgrade (line 121)

upgrade the module

this routine performs an upgrade to the installed module. Note that this module does not need any upgrade at all because there never was an earlier version.

However, if there was to be a newer version of this module, this routine is THE place to bring the database up to date compared with the existing version. For example, if an additional field 'crew_extension' was to be added to the crew-table, it could be added using a suitable (default) value, e.g. an empty string or whatever

Any existing crew records could then be updated here to fill the new field with data, e.g.

UPDATE workshops SET crew_extension = '';

etcetera. For now this routine is a nop.

  • return: TRUE on success + output via $messages, FALSE otherwise
bool crew_upgrade (array &$messages, int $module_id)
  • array &$messages: collects the (error) messages
  • int $module_id: the key for this module in the modules table

Documentation generated on Tue, 28 Jun 2016 19:09:01 +0200 by phpDocumentor 1.4.0