Coding - Passion
This blog will act as a repository of my day to day technical issues, findings, learnings and solutions. Will cover any/all technology I get to work with including Microsoft .Net, XML, JavaScript, Microsoft AJAX, SQL, Sybase to name a few. It will occassionally contain a few of my musings and rantings too.
Sunday, June 2, 2013
Infosys brings back Narayanamurthy - my take
Sunday, April 28, 2013
System cannot log you on now as the domain is not available - Fix
Since I did have the admin rights on the machine, I was able to regedit myself the next day after I consulted with a nice gentleman from the tech support team
Step1:
1. Start --> Run --> RegEdit and hit enter
2. Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
3. Look for the key cachedlogonscount
4. Set the value to a 3 or a 5
5. Log off and log on while you are on the network for a couple of times to get the credentials cached
That is it. With your credentials cached, you would be able to log on to your system even while you are NOT connected to the network domain.
Sunday, September 30, 2012
How to remove ad.yieldmanager, ad.doubleclick.net, ad.xtendmedia adware/spyware
Sunday, November 21, 2010
Scrolling to the Top of an Aspx page conditionally
I tried registering a javascript to scroll the window to co-ords 0,0 - which did not work.
If I made the page to always scroll to the top, then on EACH callback, the page would go right up - which is wrong again. So had to flag it and follow up and on a conditional basis.
For which I had to make the below code changes to get the page to scroll correctly:
Add the following to the markup:
<script language="javascript" type="text/javascript"> var errorEncountered; errorEncountered = 0; function scrollTop() { if (errorEncountered == 1) { Sys.WebForms.PageRequestManager.getInstance().add_endRequest(scrollTop2); }; } function scrollTop2() { if (errorEncountered == 1) { scrollTo(0, 0); errorEncountered = 0; }; } </script>
Add the following to the code behind at the catch of an exception on save:
System.Web.UI.ScriptManager.RegisterClientScriptBlock(Me, Me.GetType(), "Script", "errorEncountered=1;scrollTop();", True)
Wednesday, June 2, 2010
Flex Glass Headers
When i first started to work in Flex almost a year back, I was so eagerly looking to grab as much goodies as possible and make my application look spiffy. I remember staying all night long at work so many times, just to explore options by visiting many sites and applications built using Flex, primarily to get sources of inspiration.
One such application was the Flex Style Explorer. The one thing that I loved the most was the mild glossy look it had on its title; Luckily it had the view source enabled and I went on to see how the guys had done that.
It was a mere reference to a transparent flash sprite compiled into a swiff file and was referred from inside the CSS - set as the backgroundImage of the panel.
I went on to build my own header using flash in the next few minutes and added my own version of the glossy look to my application.
Click here to see the image of my app title before and after.
It was such a mild difference, people could hardly notice it; but it hugely enhanced the overall aesthetics of my application. People LOVED the look and feel but no one guessed it. I went on to use this header smartly across the application onto different controls wherever possible.
Flex Renderer Recycling
Often this could burn your time if not handled properly at the time of building your application.
The Problem:
When you scroll through a list control which has a huge list of items and is bound with an itemRenderer, the items in the list control tend to shift its positions randomly, as you scroll.
The Reason:
Flex by default tries to reuse the item renderers. In other words lets say your list control has about 40 items. It is not necessary that Flex would generate 40 itemRenderers to display the list.
Instead, based on the display area available, it would generate a few itemRenderers, just enough to handle the current display area and probably a few more for buffering.
As the users scroll through the same itemRenderers get reused and the contents that need to be displayed, in other words the next item data will be rewritten onto that itemRenderer.
So in total the creationComplete event on the item renderer would just fire once and it is not necessary that it would fire for every item added to the list again because of this reusing concept.
The Solution:
Override the set data function on your itemRenderer which would give you access to the actual item that is being bound to the itemRenderer at that point in time, and in this function you could take care of binding the item the way you want.
The set data is bound to get called many times during the process of creation/change resize etc...
For an example of overcoming the renderer recycling issue and how to override the set data function, check the example here.
Flex TileList ItemRenderer with Drag and Drop Sample
This one is a simple but nice - drag and drop example from one of the modules I had built. It is not the entire application of course; just a stripped down to basics version that just explains a few
The example handles issues like renderer recycling and explains how a custom item renderer can be used which in turn could have its own set of child controls.
The source for this can be found here and a live example here.
P.S.: When viewing the demo, just click on Open if your browser prompts you about handling the file.
Monday, March 1, 2010
Flex Expand Collapse Panel - Custom Component
It is a simple component extending the Panel and just adds a small Maximize/Minimize toggle button on the top right corner that resizes the panel based on the dimensions specified in the markup.
I blame the requirement for the simplicity of this component. It is just what they wanted. Nothing fancy about it.
It was quite simple to do. The only challenge was to deal with Flex as it does not know what to do when the component has its own set of child components declared internally and also when we try to add a few more, at the declaration…
The solution was pretty straightforward. The source code is available here and I tried to host an example here. When viewing the demo, just click on Open if your browser prompts you about handling the file.
Friday, August 14, 2009
Flex Time
Anyways, working late night continuously has helped me gain some decent level of fluency in coding with Flex. The Java Web Services were pretty straightforward.
Also, since I was at times given company by my colleague who is from Orissa, I have learnt how to swear in Orriya. I often swear at the Flex builder for being so shamelessly slow or at some of the insipid methods or definitions in ActionScript.
Somehow a few of the bigger challenges have been taken care of. There are a few more to go before we reach the comfort zone. Of course, when the testing phase is on it could all come down – but then that is a different story altogether.
Wednesday, July 8, 2009
Dynamic Menu using Flex
A dynamic menu - fully populated from data stored in MS SQL - fed via a web service.
It is important to mention that most of the functionality was pretty much handled in the web service (IMO, that is how it should be).
The only thing I learnt in flex through this project was to use the Menu control and to perform a simple WS call.
The database has a table 'tbl_menu' that stores all the menu details. It references itself via the field ParentMenu_id for sub menus.
The only input the Flex page needs is a cleanly formatted xml string. So that is what the WS is going to return:
[WebMethod]
public string GetMenuByClass(String usrclass)
{
StringBuilder sb = new StringBuilder();
Dictionary> dict = new Dictionary >();
dict = GetMenuDict(usrclass);
sb.Append("");
sb.Append("");
return sb.ToString();
}
It is just a plain method that uses StringBuilder to append the xml string. There are a hundred different ways to construct the xml, but that is not part of this sample.
Also you would notice soon that we are using a simple object class 'MenuInfo' that represents the actual DB entity which will be used that to pass around data.
Next, the GetMenuDict function takes care of populating a dictionary with all the menu data it pulled from the DB:
private Dictionary> GetMenuDict(string userAccessCode)
{
Dictionary> dict = new Dictionary >();
ListmenuItems = new List ();
menuItems = GetMenuFromDB(userAccessCode);
foreach (MenuInfo m in menuItems)
{
// root element - 0 or NULL
if (m.Parent_Link_id == 0)
{
if (dict.ContainsKey(m.Parent_Link_id))
{
dict[m.Parent_Link_id].Add(m);
}
else
{
Listlst = new List ();
lst.Add(m);
dict.Add(m.Parent_Link_id, lst);
}
}
else
{
// not a root element - parent exists. find it and add this guy to his list
MenuInfo mInfo = null;
foreach (int key in dict.Keys)
{
mInfo = FindMenuInfoRecursive(m.Parent_Link_id, dict[key]);
if (mInfo != null)
{
mInfo.menuList.Add(m);
}
}
}
}
return dict;
}
The GetmenuFromDB just reads the data from the Database using a datareader and returns a list of MenuInfo. The more inportant function is the FindMenuInfoRecursive, which takes care of handling the sub menus. With this method the sample supports infinite level of sub listing menu items, by just setting the appropriate ParentMenu_id.
private MenuInfo FindMenuInfoRecursive(int id, ListmenuList)
{
MenuInfo menu = null;
foreach (MenuInfo item in menuList)
{
if (item.Menu_id == id)
{
menu = item;
break;
}
else
{
menu = FindMenuInfoRecursive(id, item.menuList);
if (menu != null)
{
break;
}
else
{
continue;
}
}
}
//finally return the menu object
return menu;
}
The AddXmlString is the method we are going to see next:
private string AddXmlString(ListmenuList)
{
StringBuilder sb = new StringBuilder();
foreach (MenuInfo m in menuList)
{
if (m.menuList.Count > 0)
{
//should continue
sb.Append(String.Format("- ", m.Name, m.Name));
", m.Name, m.Name));
sb.Append(AddXmlString(m.menuList));
sb.Append(String.Format("
}
else
{
sb.Append(String.Format("- ", m.Name, m.Name));
}
}
return sb.ToString();
}
With all this done at the WS, it leaves us with very little to do at the Flex end. We would just be making the call to the WS and merely bind the results.
public function WSMenuSvcResultHandler(event:ResultEvent):void{
var dataXML:XML = new XML();
dataXML = XML(event.result.toString());
var myMenu:Menu = Menu.createMenu(null, dataXML, false);
myMenu.labelField="@label";
myMenu.show(10, 20);
}
The full C# source for this example is here and the Flex source is here.