ASP.NET: Dealing with object types as parameters when updating in ObjectDataSource

Question

How do you guys update let's say for example a FormView with an ObjectDataSource source. The DataObjectTypeName is a class which I have already marked with a DataObject attribute. Now, I want to customize the update process and add some custom data to the parameter. What do we need to do so?

Example: I have a BLL class which let's call it "ProductsBLL" and a data class "Product".

I declare the following ObjectDataSource control:

<asp:ObjectDataSource ID="ObjectDataSource1" runat="server" 
DataObjectTypeName="Product" OldValuesParameterFormatString="original_{0}"
SelectMethod="GetProduct" TypeName="Assembly.ProductsBLL" 
UpdateMethod="UpdateProduct">
  <UpdateParameters>
    <asp:Parameter Name="product" Type="Object" />
  </UpdateParameters>
  <SelectParameters>
    <asp:QueryStringParameter Name="productID" QueryStringField="ProdID" Type="Int32" />
  </SelectParameters>
</asp:ObjectDataSource>

Given that the Update method in the ProductsBLL class accepts a Product object as a parameter. Now, before the update takes place, I want to add a custom data to the Product parameter. How can I do that?

Answer 1

I'm not sure exactly what your question is (you need to be more specific), but the general flow is as follows:

• Your GridView is linked to an ObjectDataSource.

• Your ObjectDataSource is linked to a Biz Logic layer via the TypeName property - This is the class that will be instantiated for performing data operations. (call it ProductsBLL for example).

• It also uses an DataObjectTypeName property which is the type of object being retrieved/updated/deleted by the BLL. (say, Product)

• Also, it specifies the methods in the BLL to call whenever an action is invoked (UpdateMethod, SelectMethod, etc.) (say, ProductsBLL.UpdateProducts, ProductsBLL.DeleteProducts)

• Your BLL object then performs custom operations such as validation logic on the data received from the ObjectDataSource and calls your Datalayer to perform the actual updation/deletion from the database. (say, ProductsDataLayer.UpdateProduct())

If you need more information, please edit your question to be more specific.

Edit (after edit to original question):

---

Modifying the Product parameter before update would be as simple as:

// In Biz Logic Layer.
public int UpdateProduct(Product p)
{
  // Modify the ProductName and the Price properties of this Product.
  p.ProductName = "Product " + p.ProductName;
  p.Price = 0.95 * p.Price;

  // Call DataLayer.
  return ProductDL.UpdateProduct(p.ID, p.ProductName, p.Quantity, p.Price);
}

where the ProductDL.UpdateProduct might look like:

public int UpdateProduct(string productID, string productName, int productQty, float productPrice)

Answer 2

In the ObjectDataSource updating event, check the e.InputParameters collection, your Products object should be stored in e.InputParameters[0].