Monday, May 30, 2011

Scenario management for .ashx handlers.

    /// <summary>
    /// Scenario has three parts
    /// 1. A test that returns true or false
    /// 2. A method to run if the test is true.
    /// 3. A response object that has some details such as error messages.
    /// Benefits, your main entry point to the application is clean.
    /// The scenarios should be of a relatively similar type, this is not a service locator.
    /// For example the file up loader has three different save types, so there are three different scenarios.
    /// </summary>
    public class ScenarioHttpContext
        public Func<HttpContextbool> Test { getset; }
        public Func<HttpContextScenarioResponse> DoWork { getset; }
        public ScenarioHttpContext(Func<HttpContextbool> test, Func<HttpContextScenarioResponse> doWork)
            Test = test;
            DoWork = doWork;
        public static List<ScenarioResponse> RunActions(List<ScenarioHttpContext> scenarios, HttpContext context,bool runAll = false)
            Contract.Requires<ArgumentNullException>(context != null);
            Contract.Requires<ArgumentNullException>( scenarios != null);
            Contract.Requires<ArgumentOutOfRangeException>(scenarios != null || scenarios.Count > 0, "Cannot be null or have zero list items.");
            Trace.WriteLine("Starting ->" + MethodBase.GetCurrentMethod().Name); 
            var resp = new List<ScenarioResponse>();
            //if the test returns true then run the method
            foreach (var scenario in scenarios.Where(scenario => scenario.Test(context)))
                Trace.WriteLine(scenario + "Was called.");
                var a = scenario.DoWork(context);
                a.Name = scenario.ToString();
                if (!runAll) { break; }
            Trace.WriteLine(string.Format("A total of {0} scenarios evaluated true and ran.", resp.Count.ToString()));
            Trace.WriteLine("Ending ->" + MethodBase.GetCurrentMethod().Name);
            return resp;
    public class ScenarioResponse
        public string Name { getset; }
        public bool Success { getset; }
        public string ErrorMsg { getset; }
    public static class ScenarioHttpContextExtensions
       /// <summary>
       /// </summary>
       /// <param name="scenario">Unit of work</param>
       /// <param name="test">If statement to determine if this scenario should be run.</param>
       /// <param name="workToDo">The work to do if the scenario test is true</param>
        public static void AddNew(this List<ScenarioHttpContext> scenario ,Func<HttpContextbool> test, Func<HttpContext,ScenarioResponse > workToDo)
            Contract.Requires<ArgumentNullException>(scenario != null);
            scenario.Add(new ScenarioHttpContext(test, workToDo));

Saturday, May 21, 2011

jquery Autocomplete with previous dropdown

The html is simple we have a  dropdown box, ddlist and a textbox called textbox.
Please double check the names, I changed them in notepad.

This solution also fixes the issue where the dropdown list item is cashing the selected value from page load.

The first function erases the value of the textbox when the dropdown list changes.

$("#ddlist").change(function () {
    alert($('#ddlist option:selected').text());
This function kicks off the autocomplete process when the user clicks in the box.
If the value of the ddl is not good, then throw up a hint. 
$("#textbox").live("focus"function () {
    var marketVal = $('#ddlist option:selected').text();
    if (marketVal != '') {
        var sourceUrl = 'mypage.ashx?action=dosomething&ddlistName=' + $('#ddlist option:selected').text();
            source: sourceUrl,
            minLength: 2
            //select: function (event, ui) { $("#SubMarket").val(; }
    } else {
        alert("Please choose a Market item first");

Tuesday, May 3, 2011


Such a simple, but commonly over looked function.  When writing inline sql, (yes, it still happens), try to use string.format(...) vs. "text" + "text" + someVar.

I wish I had time to post samples of both, so you can see the readablity difference.