How to set Component parameters in J2.5? - joomla

Question

I've created a J2.5 component with some config fields using config.xml in the admin folder of the component.
How can I set parameters in the config programatically?
I've tried the code bellow, but it obviously doesn't save the result to the DB:
$params = & JComponentHelper::getParams('com_mycomponent');
$params->set('myvar', $the_value);
Could anyone please show some examples of how to achieve this?

Answer 1

The safest way to do this would be to include com_config/models/component.php and use it to validate and save the params. However, if you can somehow validate the data params yourself I would stick with the following (much more simple solution):
// Get the params and set the new values
$params = JComponentHelper::getParams('com_mycomponent');
$params->set('myvar', $the_value);
// Get a new database query instance
$db = JFactory::getDBO();
$query = $db->getQuery(true);
// Build the query
$query->update('#__extensions AS a');
$query->set('a.params = ' . $db->quote((string)$params));
$query->where('a.element = "com_mycomponent"');
// Execute the query
$db->setQuery($query);
$db->query();
Notice how I cast the params to a string (when building the query), it will convert the JRegistry object to a JSON formatted string.
If you get any caching problems, you might want to run the following after editing the params:
From a model:
$this->cleanCache('_system');
Or, else where:
$conf = JFactory::getConfig();
$options = array(
'defaultgroup' => '_system',
'cachebase' => $conf->get('cache_path', JPATH_SITE . '/cache')
);
$cache = JCache::getInstance('callback', $options);
$cache->clean();

Answer 2

The solution is here...
http://www.webtechriser.com/tutorials/82-joomla-3-0/86-how-to-save-component-parameters-to-database-programmatically
You can replace in Joomla 2.5+ the
// check for error
if (!$table->check()) {
$this->setError('lastcreatedate: check: ' . $table->getError());
return false;
}
if (!$table->store()) {
$this->setError('lastcreatedate: store: ' . $table->getError());
return false;
}
with
if (!$table->save()) {
$this->setError('Save Error: ' . $table->getError());
return false;
}