public function set_display_name($model_classname, $field_expression)
	{
	    $model_instance = $this->get_model_instance($model_classname);
	    
	    $schema = $model_instance->schema();
	    
	    if(array_key_exists($field_expression, $schema)
	        ||
	       array_key_exists(str_replace($model_classname . '.', '', $field_expression), $schema)
	        ||
	       array_key_exists($field_expression, $model_instance->virtualFields))
	    {
	        /*
	         * The field does not need to be created as it already exists in the model
	         * as a datatable field, or a virtual field configured in the model
	         */
	        
	        /*
	         * Eventually remove the model name
	         */
	        if(strpos($field_expression, $model_classname . '.') === 0)
	        {
	            $field_expression = str_replace($model_classname . '.', '', $field_expression);
	        }
	        
	        return $field_expression;
	    }
	    else
	    {
	        /*
	         * The field does not exist in the model
	         * -> create a virtual field with the given expression
	         */
	        
	        $this->controller->{$model_classname}->virtualFields['alaxos_acl_display_name'] = $field_expression;
	        
	        return 'alaxos_acl_display_name';
	    }
	}
public function set_display_name($model_classname, $field_expression)
	{
	    $model_instance = $this->get_model_instance($model_classname);
	    
	    $schema = $model_instance->schema();
	    
	    if(array_key_exists($field_expression, $schema)
	        ||
	       array_key_exists(str_replace($model_classname . '.', '', $field_expression), $schema)
	        ||
	       array_key_exists($field_expression, $model_instance->virtualFields))
	    {
	        /*
	         * The field does not need to be created as it already exists in the model
	         * as a datatable field, or a virtual field configured in the model
	         */
	        
	        /*
	         * Eventually remove the model name
	         */
	        if(strpos($field_expression, $model_classname . '.') === 0)
	        {
	            $field_expression = str_replace($model_classname . '.', '', $field_expression);
	        }
	        
	        return $field_expression;
	    }
	    else
	    {
	        /*
	         * The field does not exist in the model
	         * -> create a virtual field with the given expression
	         */
	        
	        $this->controller->{$model_classname}->virtualFields['alaxos_acl_display_name'] = $field_expression;
	        
	        return 'alaxos_acl_display_name';
	    }
	}
public function set_display_name ( $ model_classname , $ field_expression ) { $ model_instance = $ this -> get_model_instance ( $ model_classname ) ; $ schema = $ model_instance -> schema ( ) ; if ( array_key_exists ( $ field_expression , $ schema ) || array_key_exists ( str_replace ( $ model_classname . '.' , '' , $ field_expression ) , $ schema ) || array_key_exists ( $ field_expression , $ model_instance -> virtualFields ) ) { /*
	         * The field does not need to be created as it already exists in the model
	         * as a datatable field, or a virtual field configured in the model
	         */ /*
	         * Eventually remove the model name
	         */ if ( strpos ( $ field_expression , $ model_classname . '.' ) === 0 ) { $ field_expression = str_replace ( $ model_classname . '.' , '' , $ field_expression ) ; } return $ field_expression ; } else { /*
	         * The field does not exist in the model
	         * -> create a virtual field with the given expression
	         */ $ this -> controller -> { $ model_classname } -> virtualFields [ 'alaxos_acl_display_name' ] = $ field_expression ; return 'alaxos_acl_display_name' ; } }
Check if a given field_expression is an existing fieldname for the given model

If it doesn't exist, a virtual field called 'alaxos_acl_display_name' is created with the given expression

@param string $model_classname
@param string $field_expression
@return string The name of the field to use as display name
Check if a given field_expression is an existing fieldname for the given model