componentlib.class.php File Reference

This library includes all the necessary stuff to use the one-click download and install feature of Moodle, used to keep updated some items like languages, pear, enviroment... i.e, components. More...

Classes
class	component_installer
	This class is used to check, download and install items from download.moodle.org to the moodledata directory. More...
class	lang_installer
	End of component_installer class. More...
class	lang_installer_exception
	Exception thrown by lang_installer. More...

Variables
global object	$CFG
	$CFG
const	COMPONENT_ERROR 0
const	COMPONENT_INSTALLED 3
const	COMPONENT_NEEDUPDATE 2
const	COMPONENT_UPTODATE 1

Detailed Description

This library includes all the necessary stuff to use the one-click download and install feature of Moodle, used to keep updated some items like languages, pear, enviroment... i.e, components.

It has been developed harcoding some important limits that are explained below:

• It only can check, download and install items under moodledata.
• Every downloadeable item must be one zip file.
• The zip file root content must be 1 directory, i.e, everything is stored under 1 directory.
• Zip file name and root directory must have the same name (but the .zip extension, of course).
• Every .zip file must be defined in one .md5 file that will be stored in the same remote directory than the .zip file.
• The name of such .md5 file is free, although it's recommended to use the same name than the .zip (that's the default assumption if no specified).
• Every remote .md5 file will be a comma separated (CVS) file where each line will follow this format:
  • Field 1: name of the zip file (without extension). Mandatory.
  • Field 2: md5 of the zip file. Mandatory.
  • Field 3: whatever you want (or need). Optional. -Every local .md5 file will:
  • Have the zip file name (without the extension) plus -md5
  • Will reside inside the expanded zip file dir
  • Will contain the md5 od the latest installed component With all these details present, the process will perform this tasks:
• Perform security checks. Only admins are allowed to use this for now.
• Read the .md5 file from source (1).
• Extract the correct line for the .zip being requested.
• Compare it with the local .md5 file (2).
• If different:
  • Download the newer .zip file from source.
  • Calculate its md5 (3).
  • Compare (1) and (3).
  • If equal:
    • Delete old directory.
    • Uunzip the newer .zip file.
    • Create the new local .md5 file.
    • Delete the .zip file.
  • If different:
    • ERROR. Old package won't be modified. We shouldn't reach here ever.
• If component download is not possible, a message text about how to do the process manually (remotedownloaderror) must be displayed to explain it.

General Usage:

To install one component: require_once($CFG->libdir.'/componentlib.class.php'); if ($cd = new component_installer('https://download.moodle.org', 'langpack/2.0', 'es.zip', 'languages.md5', 'lang')) { $status = $cd->install(); //returns COMPONENT_(ERROR | UPTODATE | INSTALLED) switch ($status) { case COMPONENT_ERROR: if ($cd->get_error() == 'remotedownloaderror') { $a = new stdClass(); $a->url = 'https://download.moodle.org/langpack/2.0/es.zip'; $a->dest= $CFG->dataroot.'/lang'; print_error($cd->get_error(), 'error', '', $a); } else { print_error($cd->get_error(), 'error'); } break; case COMPONENT_UPTODATE: //Print error string or whatever you want to do break; case COMPONENT_INSTALLED: //Print/do whatever you want break; default: //We shouldn't reach this point } } else { //We shouldn't reach this point }

To switch of component (maintaining the rest of settings): $status = $cd->change_zip_file('en.zip'); //returns boolean false on error

To retrieve all the components in one remote md5 file $components = $cd->get_all_components_md5(); //returns boolean false on error, array instead

To check if current component needs to be updated $status = $cd->need_upgrade(); //returns COMPONENT_(ERROR | UPTODATE | NEEDUPDATE)

To get the 3rd field of the md5 file (optional) $field = $cd->get_extra_md5_field(); //returns string (empty if not exists)

For all the error situations the $cd->get_error() method should return always the key of the error to be retrieved by one standard get_string() call against the error.php lang file.

That's all!

Copyright

(C) 2001-3001 Eloy Lafuente (stronk7)

License

http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later