/**
* Perform commands to upgrade/downgrade the version of the class from $from_ver to $to_ver
*
* @param string $from_ver
* @param string $to_ver
* @return bool TRUE on success, FALSE on nothing to update
* @throws exception on command error
*/
function migrate($from_ver, $to_ver)
{
if (version_compare($from_ver, $to_ver) > 0) {
$this->output("Downgrading from {$from_ver} to {$to_ver}");
// $from_ver is bigger than to_ver - downgrade
// Start with the from_ver, and execute each command in reverse order untill
// reaching to_ver, but to execute any of the to_var commands
// Example: from_ver = 2.1, to_ver = 1.5
$prev_ver = false;
foreach (array_reverse($this->log) as $ver => $commands) {
if ($prev_ver) {
// yeald to the caller - we need to save the installed cache on each mirgated version
$this->install->installed[$this->class] = $prev_ver;
$this->install->saveInstalled();
}
if (version_compare($ver, $to_ver, '<=')) {
break;
}
// Stop at the "to_ver" w/out executing any of the commands
// Example - break if ver = 1.5, 1.2, 1.1, but not when ver = 1.8
if (version_compare($ver, $from_ver, '>')) {
continue;
}
// Skip commands in the version before entering the from_ver span
// Example - skip if ver = 2.5 or 3.0 or 2.1.1 BUT NOT IF ver is 2.1 or 2.0.1 or 1.6
$this->output("Undoing version {$ver}");
foreach (array_reverse($commands) as $cmd) {
if (isset($cmd['down'])) {
$this->output("Running {$cmd['callback']}");
call_user_func_array(array($this, $cmd['callback']), $cmd['down']);
}
}
$prev_ver = $ver;
}
return true;
} elseif (version_compare($from_ver, $to_ver) < 0) {
$this->output("Upgrading from {$from_ver} to {$to_ver}");
// $to_ver is bigger than from_ver - upgrad
// Start with the from_ver, but skip it (it is already executed) and move on untill
// reaching the last of the $to_ver commands
// Example: from_var = 1.5, to_var=1.9
foreach ($this->log as $ver => $commands) {
if (version_compare($ver, $to_ver, '>')) {
break;
}
// The to_ver must be the lastly exeuted command
// Example - break if ver = 2.0, 1.9.4, 3.1, but not when ver = 1.8 or 1.0 or 1.9
if (version_compare($ver, $from_ver, '<=')) {
continue;
}
// Skip commands in the version before entering the from_ver span, incl the from_ver
// Example - skip if ver = 1.1 or 1.0 or 1.5 BUT NOT IF ver is 1.5.1 or 2.0 or 1.9
foreach ($commands as $cmd) {
if (isset($cmd['up'])) {
$this->output("Running {$cmd['callback']}");
call_user_func_array(array($this, $cmd['callback']), $cmd['up']);
}
}
$this->output("Updated to version {$ver}");
$this->install->installed[$this->class] = $ver;
$this->install->saveInstalled();
}
return true;
} else {
// Versions are equal - nothing to upgrade
return false;
}
}
