/**
* Allows a field's type, uniqueness, nullability, default, column, constraints etc. to be modified.
*
* Requires a copy of the old field as well so we can only perform changes that are required.
* If strict is true, raises errors if the old column does not match old_field precisely.
*
* @param Model $model
* @param Field $oldField
* @param Field $newField
* @param bool|false $strict
*
* @since 1.1.0
*
* @author Eddilbert Macharia (http://eddmash.com) <*****@*****.**>
*/
public function alterField($model, $oldField, $newField, $strict = false)
{
$oldType = $oldField->dbType($this->connection);
$newType = $newField->dbType($this->connection);
if ($oldType == null && $oldField->relation == null || $newType == null && $newField->relation == null) {
throw new ValueError(sprintf('Cannot alter field %s into %s - they do not properly define ' . 'db_type (are you using a badly-written custom field?)', $newField->name, $oldField->name));
} elseif ($oldType == null && $newType == null && ($oldField->relation->through != null && $newField->relation->through != null && $oldField->relation->through->meta->autoCreated && $newField->relation->through->meta->autoCreated)) {
$this->_alterManyToMany($model, $oldField, $newField, $strict);
} elseif ($oldType == null && $newType == null && ($oldField->relation->through != null && $newField->relation->through != null && !$oldField->relation->through->meta->autoCreated && !$newField->relation->through->meta->autoCreated)) {
return;
} else {
throw new ValueError(sprintf('Cannot alter field %s into %s - they are not compatible types ' . '(you cannot alter to or from M2M fields, or add or remove through= on M2M fields)', $oldField->name, $newField->name));
}
$this->_alterField($model, $oldField, $newField, $strict);
}
