WebGrid API changes - Migration Guide

Overview

ALVAO version 26.3 introduced breaking changes to the WebGrid base class to support async/await patterns and improve code organization. All classes that inherit from WebGrid need to be updated.

Summary of Changes

1. InitialSelect() → InitialSelectAsync()

   • Changed from synchronous to asynchronous
   • Now returns Task<SelectCallbackResponse> instead of SelectCallbackResponse
   • No longer needs to be overridden in derived classes

2. New virtual method: OnInitialSelect(SelectCallbackResponse response)

   • Optional override for setting up initial parameters
   • Called automatically by InitialSelectAsync() before executing the response

3. GetSelCallRes() → GetSelectCallbackResponse()

   • Method renamed for clarity
   • Signature remains the same: SelectCallbackResponse GetSelectCallbackResponse(CallbackModel model)

Required Changes in Derived Classes

✅ Change 1: Rename GetSelCallRes to GetSelectCallbackResponse

Before:

public override SelectCallbackResponse GetSelCallRes(CallbackModel model)
{
    return new MySelectResponse(model, this);
}

After:

public override SelectCallbackResponse GetSelectCallbackResponse(CallbackModel model)
{
    return model != null 
        ? new MySelectResponse(model, this)
        : new MySelectResponse(this);
}

✅ Change 2: Remove InitialSelect() override and use OnInitialSelect() instead

Before:

public override SelectCallbackResponse InitialSelect()
{
    SelectCallbackResponse resp = new MySelectResponse(this);
    resp.Execute();
    resp.AdditionalParameters["MyParam"] = MyValue.ToString();
    return resp;
}

After:

public override void OnInitialSelect(SelectCallbackResponse response)
{
    // Set up any initial parameters on the response if needed
    response.AdditionalParameters["MyParam"] = MyValue.ToString();
}

note

If you didn't override InitialSelect() in your grid, you don't need to add OnInitialSelect() either. The base implementation handles everything.

✅ Change 3: Update HandleCallbackAsync method

Before:

public override async Task<CallbackResponse> HandleCallbackAsync(CallbackModel model)
{
    CallbackResponse resp = null;
    switch (model.callback)
    {
        case "select":
            resp = GetSelCallRes(model);
            await resp.ExecuteAsync();
            break;
    }
    return resp;
}

After:

public override async Task<CallbackResponse> HandleCallbackAsync(CallbackModel model)
{
    CallbackResponse resp = null;
    switch (model.callback)
    {
        case "select":
            resp = GetSelectCallbackResponse(model);
            await resp.ExecuteAsync();
            break;
    }
    return resp;
}

note

If you didn't override HandleCallbackAsync() in your grid, you don't need to change anything.

Complete Example

Old Implementation:

public class MyCustomGrid : WebGrid
{
    public int EntityId { get; set; }

    public override SelectCallbackResponse InitialSelect()
    {
        SelectCallbackResponse resp = new MySelectResponse(this);
        resp.Execute();
        resp.AdditionalParameters["EntityId"] = EntityId.ToString();
        return resp;
    }

    public override SelectCallbackResponse GetSelCallRes(CallbackModel model)
    {
        return new MySelectResponse(model, this);
    }
}

New Implementation:

public class MyCustomGrid : WebGrid
{
    public int EntityId { get; set; }

    public override void OnInitialSelect(SelectCallbackResponse response)
    {
        response.AdditionalParameters["EntityId"] = EntityId.ToString();
    }

    public override SelectCallbackResponse GetSelectCallbackResponse(CallbackModel model)
    {
        return model != null 
            ? new MySelectResponse(model, this)
            : new MySelectResponse(this);
    }
}

Key Points

• InitialSelectAsync() is now in the base class - don't override it unless you have a very specific reason
• Use OnInitialSelect() for setup - set additional parameters or perform initialization before the query executes
• The base class handles async execution - you no longer need to call Execute() or ExecuteAsync() in InitialSelect()