ASP.Net - Ajax - Sample

Ajax was a technology added to ASP.Net Web Pages. Basicially it allowed you to add Javascript to your web page that would make a call to your server, to send and or retrieve data, without causing the web page to perform a postback.

JavaScript

This function is activated when I press the generate button

function GenerateHistoryInitialize(dbCode, tableName) {
    var chkManageDdTable = $('#<%= chkManageDdTable.ClientID %>').is(':checked');
    var ddlDatabaseType = $('#<%= ddlDatabaseType.ClientID %>').val();

    var params = new Object();
    params.dbCode=dbCode;
    params.manageDdTable = chkManageDdTable;
    params.tableName = tableName;
    params.outputDatabaseType = ddlDatabaseType;
    
    //alert  (JSON.stringify(params));
    $.ajax({
        type: 'POST',
        url: 'ajax.aspx/GenerateHistoryInitialize',
        data: JSON.stringify(params),
        contentType: "application/json; charset=utf-8",
        success: function (msg) {
            //
            // good. It succeeded
            //
            $('#txtBlocksDone').val(parseInt($('#txtBlocksDone').val()) + 1);
            $('#<% =txtOutput.ClientID %>').val($('#<% =txtOutput.ClientID %>').val() + msg.d);
        },
        failure: function (msg) {
            alert('Failure in CreateTriggers - ' + msg.d);
            $('#txtBlocksDone').val(parseInt($('#txtBlocksDone').val()) + 1);
        }
    })
}

It ends up calling the following server side code contained in ajax.aspx.vb

<System.Web.Services.WebMethod()>
<Script.Services.ScriptMethod(ResponseFormat:=Script.Services.ResponseFormat.Json)>
Public Shared Function GenerateHistoryInitialize(
        ByVal dbCode As String,
        ByVal manageDdTable As Boolean,
        ByVal tableName As String,
        ByVal outputDatabaseType As String
        ) As String

    Dim sz As String = ""

    Console.WriteLine("***")
    Dim dbId As String _
        = dbCls.GetDbIdByDbCode(dbCode)

    Dim aDb As dbCls _
        = dbCls.GetOneByDbId(dbId)

    Dim connectionString As String _
        = aDb.StructureConnectionString

    Dim databaseName As String _
        = aDb.DatabaseName

    Dim aTable As New si.aTable(tableName)
    Dim al As System.Collections.ArrayList _
        = aTable.getColumns(aDb.SampleDataDriverTypeEnum, connectionString, "", 0, "", "", "")
    Dim pk As String _
        = aTable.getPrimaryKeyColumnName(connectionString, tableName, aDb.SampleDataDriverTypeEnum)

    Return si.CodeGenHistory.GenerateHistoryInitialize(
         manageDdTable, tableName, pk,
         si.Structures.ComputeDatabaseType(outputDatabaseType))

End Function