Primarily parameters capture the data that accompany events.

However, the usage of parameters could be general in nature.  For example, for platforms that have dynamic object creation and life cycle management, these parameters could be used to represent dependant object as well as data keys.

For dynamic segment composition schemes, these parameters could be used to customize included segments at runtime.

The point here is that apart from event parameters, the general implementation implications of parameters would differ from platforms to platforms.

For events the id for the parameters descriptors would be registered against the event. For page composition, the parameters would have a parent, which would the segment that represents the included page.

The parameters descriptor could describe 1) an object that hold the properties that would be used as parameters, 2) or map object, or collection of objects that hold the key and value parameter pairs. 3) In addition, it could be a parent to one or more parameter descriptors.  The latter "parameter" singular descriptor, affords a finer grain parameter binding of individual key and value pair; whereas the "parameters" are bound to collection, or whole object.

Link or GET Request Parameters

The implementation code would be as shown below.

<asp:hyperlink id="AssocLink" runat="server" navigateurl=
'<%# String.Format("http://associates.com.aspx?referer=yourassoc.com&custemerId={0}}",
 Eval("CustemerId")) %>' text='Legal Associates'/>

The hyperlink control that could be used within a GridView, provide a more elegant means of implementing the parameters associated. The specification is shown below.

Whereas the implementation is as shown below.

  <asp:HyperLinkField runat="server"
         DataTextField="CustomerName"
         DataNavigateUrlFields="CustomerID,City"
         DataNavigateUrlFormatString=
           "http://yoursite.com/showcustomer.aspx?id={0}&city={1}" />

Data Model Parameters

Normally, the parameters that are used to determine columns to select, insert, primary keys, or where clause parameters are defined in the model. On the ASP.NET these parameters are shown and implemented as part of page. This scheme is more amenable to dragging data and dropping unto components in the IDE. With complex and large projects, such scheme might become intractable. The LINQ data source provides option for abstracting such details into the model.

dWebSpec is meant to capture specification and not to enforce programming patterns or styles. If model parameters are needed, they could be captured. The parameters descriptors are general enough in nature that they could capture certain aspects of the model parameters.

An example of this is specification for where parameters used to narrow down the selection of rows; this is illustrated below.

The implementation would be as shown below.

  <asp:LinqDataSource ID="CategoryDataSource"
     ContextTypeName="NorthwindDataContext"
     TableName="Products"
     AutoGenerateWhereClause="true"
     Runat="Server">
    <WhereParameters>
      <asp:ControlParameter
      Name="CategoryID"
      PropertyName="SelectedValue"
      Type="Int32" />
    </WhereParameters>
   </asp:LinqDataSource>   
  

The asp:XXXParameter used depends on the value specified. This is shown in the table below.

The value could be from form input element, cookie, query string, or session.