Declarative Parameters: Step 3-Showing All Suppliers by Default
This step of the VIDEO TUTORIAL will demonstrate on how to show all the suppliers by default at runtime on the web page DelcarativeParms.aspx. In order to accomplish this, a check has to be made for null value in the business logic layer method GetSuppliersByCountry(string country). If the country parameter is NULL that means, the user has entered no value and clicked on ‘Show Suppliers’ button on the web page at run time. This triggers the button’s click event and passes a NULL value as parameter to the GetSuppliersByCountry method of business logic layer. In this method, we have to verify this value, if it is NULL, we have to invoke GetSuppliers( ) method instead of GetSuppliersByCountry method which expects a string value (country) as a parameter. Therefore, we display all the suppliers by default by modifying the GetSuppliersByCountry method in the SuppliersBLL class file.For detailed information and source code for this step, please refer to the original article.