PHP and Codeigniter - How do you check if a model exists and/or not throw an error?

You can see if the file exists in the models folder.

$model = 'my_model';if(file_exists(APPPATH."models/$model.php")){   $this->load->model($model);   $this->my_model->my_fcn($prams);}else{  // model doesn't exist}

Maybe this helper function will help you to check if a model is loaded or not.

function is_model_loaded($model){    $ci =& get_instance();          $load_arr = (array) $ci->load;    $mod_arr = array();    foreach ($load_arr as $key => $value)    {        if (substr(trim($key), 2, 50) == "_ci_models")            $mod_arr = $value;    }    //print_r($mod_arr);die;    if (in_array($model, $mod_arr))        return TRUE;    return FALSE;}

source reference

Don't foget that your application may use pakages. This helper function look through all models (even in packages included in your CI app).

if ( ! function_exists('model_exists')){    function model_exists($name){        $CI = &get_instance();        foreach($CI->config->_config_paths as $config_path)if(file_exists(FCPATH . $config_path . 'models/' . $name . '.php'))return true;        return false;    }}

Cheers