error：在非对象上调用成员函数startTrans（）

Question

I am using pOWL to build a content management system of OWL files. I want to be able to query the OWL files as well as add new instances and classes. However I am stuck. I need to load the OWL file into an OWLModel using pOWL. So I tried:

$base="wine.owl";
$store = new DefaultPOWLStore(ADODB_DB_DRIVER, "localhost", "powl", "root", "password");

$model = ModelFactory::getOntModel('DBModel','RDFS_VOCABULARY', $base);
$model = new OWLModel($store, $base);
$model->load('wine.owl');

$model -> __construct($store, $base);

But I am getting the error:

Fatal error: Call to a member function startTrans() on a non-object in C:\Users\xxx\xxx\powldfapi-php\api\model\DbModel.php on line 878

The code with the error is:

    if (is_a($model, 'MemModel')) {
            if (is_object($model)){
            echo "<pre>";
            print_r("!!!!!!!");
            echo "</pre>";
        }

        $this->dbConn->startTrans();

I added the second if clause in an attempt to check if $model is an object, and it passed the clause. But I am not sure if that is the correct way to check if a variable is an object.

UPDATE: The issue seems to be with dbConn variable, need to find a way to load the model into the DB for dbConn to be defined. Will look tomorrow.

Answer 1

got around this as I was trying to load the OWL file into the model. I should have loaded the file using$store. Here is the code:

$modelURI = "http://www.w3.org/TR/2003/PR-owl-guide-20031209/wine#";
$base="wine.owl";
$filename ="wine.owl";
$store = new DefaultPOWLStore(ADODB_DB_DRIVER, "localhost", "powl", "root", "password");

if(!$store->modelExists($modelURI)) {
    $store->loadModel($modelURI, $base);
}

$model = new OWLModel($store, $modelURI);
$store-> putModel($store, $modelURI);