Osama's Weblog

I had a requirement of automate a task which could run after every 5 minutes. After spending some time on research, I decided to make a windows service and automate it. Automating a windows service is a bit tricky and it gave me a little hard time. Hence, I am sharing what did I code to complete the task.

When a new service created, OnStart & OnStop methods are initialized by default. You need to play with timers to get the task done.

Below is the code snippet which shows how to automate the windows service.

public partial class Service1

      {
        public Timer tm;  //initialize a new timer instance
        public Service1()
        {
            InitializeComponent();
        }

        protected override void OnStart(string[] args)
        {
            tm = new Timer();
            tm.AutoReset = true; //timer will reset and call the event handler function itself
            tm.Interval = 60000;  // time interval in milliseconds
            tm.Elapsed += new ElapsedEventHandler(timer_start);  //event which needs to be fired

            //once the timer reaches its maximum value
            tm.Start(); //start the timer

        }

protected void timer_start(object sender, ElapsedEventArgs e)

{

    //Perform your task here

}

protected override void OnStop()
        {
            tm.Start(); //start the timer again and it will call the event hander function again
        }

The above mentioned code snippet is self explanatory. I hope it helps whoever reads the post.

Feel free to ask questions

I had a requirement of calling a web page which shows nothing but does some processing at the back end. But later on I decided to put a progress bar to make it attractive. I used JQuery UI to show the progress bar. The issue is JQuery is a javaScript library and it runs after the server side code is done processing. And my code was on the Page_Load method.

The solution which I found was to call the processing page within an iframe of the parent page. So that the progress bar will be shown on the parent page and will be loaded as soon as the page loads and the processing will be done within an iframe.

This is what I did to implement the above scenario:

///////////////Parent Page///////////////
<form id="form1" runat="server">
<iframe id="ifrm" frameborder="0"  runat="server" />
</form>

Code behind of the parent page:
protected void Page_Load(object sender, EventArgs e)
{
ifrm.Attributes["src"] = "Default2.aspx?id=" + Request["id"];
}

This will pass the id in the query string from the parent window the the iframe page. The iframe window will get the id from the query string and will do the desired processing.

Feel free to ask questions

Few days ago I wrote a blog post in which I mentioned that I wasn’t able to access apex:input field on a force.com site. With the help of a my blog reader, I figured out what was the problem. Its pretty straight forward.

You cannot give extra permissions to standard objects on a force.com site. But  you can give Modify All Data and View All Data permissions to a custom object . That means you can use apex:inputField on a force.com site which is bound to a custom object field. Make sure about field level security.

Thanks to Jason.

JQuery has always fascinates me. It makes the UI very attractive and user friendly. I had to implement a datepicker in a text field. I decided to use the JQuery UI datepicker. I am sharing the code that I did. Its easy to understand.

I made a static resource with the name slider and uploaded all the css and js files of JQuery UI that are available for download here .

1) Include the css files in your page

<link type="text/css" href="{!URLFOR($Resource.Slider, 'themes/ui-lightness/ui.all.css')}" rel="stylesheet" />
<script type="text/javascript" src="{!URLFOR($Resource.Slider, 'jquery-1.3.2.js')}"></script>
 <script type="text/javascript" src="{!URLFOR($Resource.Slider, 'ui/ui.core.js')}"></script>
 <script type="text/javascript" src="{!URLFOR($Resource.Slider, 'ui/ui.datepicker.js')}"></script>

2) Make a input text field and create the following JQuery function as below

 <input id="datepicker" type="textbox" />
<script type="text/javascript">
    $(function() {
        $("#datepicker").datepicker({ showOn: 'button', buttonImageOnly: true, buttonImage: '{!$Resource.calendar}' });
    });
    </script>;;

3)   $(“#datepicker”).datepicker({ showOn: ‘button’, buttonImageOnly: true, buttonImage: ‘{!$Resource.calendar}’ });
The datepicker pops up when you click on the image button that is created using the above statement. If  you want to pop it up by clicking the textbox only, replace the above statement with the below one:

  $(“#datepicker”).datepicker();

I hope it helps for you as it did for me. Feel free to ask questions