I wanted every time to have a page where I can “clear” / delete those – and not found. So it’s the Clearer project.

It consists of :

1. ClearerController with 2 Actions:   Index and DeleteItem
2. 2 Views : Index.cshtml and EditAppData.cshtml
3. Different Models:
   • SourceData  – enum  – can be  :  None ,        Application ,        Cache ,        Session ,        Cookies
   • AppData -  maintains Key/Value and SourceData pairs
   • ListAppData – loads data from Application , Cache , Session , Cookies  – and deletes.

To make an example, I have put in the Application_Start and Session_Start different values. So the screen is the following:

What I learn from the code:

1. The Cookies, Applications, Session , Cache items can be easily converted to an DictionaryEntry and the code can be like this:

    DictionaryEntry de = new DictionaryEntry(item, sess[item.ToString()]);
    AddNew(de, SourceData.Session);
   

2. Code must be error prone – what if some item in Session is null ? So , if I have the Key, all is good:

   private void AddNew(DictionaryEntry de, SourceData sd)
           {
               AppData ap = new AppData() { source = sd, Key = de.Key.ToString() };
               try
               {
                   var obj = de.Value;
                   ap.Value = (obj == null) ? Null : obj.ToString();
               }
               catch (Exception ex)
               {
   
                   ap.Value = string.Format(ErrorToString, ex.Message);
               }
               this.Add(ap);
           }
   

3. The dog-food is good: I have followed my advice from msprogrammer.serviciipeweb… and it works ( used for Remove )

      [HttpPost]
           public JsonResult DeleteItem(string TheKey, int Source)
           {
               try
               {
                   var lad = new ListAppData();
                   lad.DeleteItem(TheKey, (SourceData)Source);
                   return Json(new { ok = true, message = "" });
               }
               catch (Exception ex)
               {
                   return Json(new { ok = false, message = ex.Message });
               }
   
           }
   

4. When you pass strings in Javascript, there is a simple way to encode: HttpUtility.JavaScriptStringEncode

   <a href="javascript:removeItem('@HttpUtility.JavaScriptStringEncode(Model.Key)','@((int)Model.source)','@id')">Remove</a>
   

Possible uses:

1. For developers -  when they want to see what happens when a cache item no longer exists
2. For developers – to put to site admins some simple tool to reload data from Cache/Application . Just edit the LoadAll function to load only Cache/Application
3. For developers  – to test easily the session. Just delete ASP.NET_SessionId  cookie – you will get another one when you refresh the page.

You can view online at http://clearer.apphb.com/Clearer
The project could be found at http://clearer.codeplex.com and have all – source code, downloadable project .

Next week it will be a Nuget item.

For more features , please leave me a comment here or on codeplex at issues

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This is an MVC add-on to add a messaging system to any MVC application. It costs me 0$ to make this program ( not yet finished, but free source at http://messagemvc.codeplex.com/  and the related posts are at http://msprogrammer.serviciipeweb.ro/category/howto/asp-net-mvc/mvc-4/mvc-messaging-system-mvc-4-asp-net-mvc-howto/ )

Home Computer – already done for browsing the internet.

Download Visual Studio Express – free .

Download Sql Server Express – free.

Download latest bits of EF 4.2 – to work with SqlServer Compact too – free.

(Connection to internet : 25 $ – but was already done for browsing the internet)

Installing and configuring software on my PC – 0 $.

All I have done is to sit on my home desk and tapping into the keyboard. But this is does not costs , right?

Making, Planning, testing, deploying – 0$.

[quote from=http://www.petapixel.com/2012/01/10/this-photograph-is-not-free/ ]

So if you’re a magazine, website, corporation, sports team, or advertiser developer who wishes to use this photo  software , please don’t   come and ask to use it for free, or in exchange for credit or “exposure”.

[/quote]

Do not give feedback . Just rant about how bad code smells ,about how OOP and SOLID and Design Patterns are not made clear and how Testing is not properly handled. After all, it is free , right?

www.ariel.com.au/jokes/The_Evolution_of_a_Programmer.html

And Haskell

http://www.willamette.edu/~fruehr/haskell/evolution.html

Hope you understand Haskell

And books for you:

http://www.codinghorror.com/blog/2004/02/recommended-reading-for-developers.html

In ASP.NET ( like in PHP and other Web frameworks) there are 2 clear entities: Server ( code on the WebServer ) and Client( the HTML interpreted by the browser and javascript).

Server and Client shares same cookies – means Client and Client both can read and write cookies.

Transfer from the Client to Server happens when

a) you click a link : the information to transfer is query string . That means, http://…/a?x=y&a=b will send information y ( associated to key x) and b( associated to key a). This is called a GET

b) you press a submit button to send a FORM : the information is values of select and input. This is called a POST.

c) you send information via javascript ( including AJAX) . Usually this can involve a PUT, a GET, or other ( see REST ).

d) Creating/Modifying and send cookies. The sending happens automatically by the browser .

Transfer from the Server to Client

a)sending text(HTML)/binary data. . The interpretation is done by the browser( how to display html, how to display send file …)

b) Creating/Modifying and send cookies . Browser will do automatically this.

ASP.NET WebForms way:

For ASP.NET Webforms the modalities to transfer are detailed by Peter Bromberg , http://www.eggheadcafe.com/tutorials/asp-net/e653f028-01fb-4d0e-843b-058deae562a2/eight-different-ways-to-transfer-data-from-one-page-to-another-page.aspx .

ASP.NET MVC way:

I want to discuss from ASP.NET MVC perspective. In MVC we have 2 distinct objects: VIEW and ACTION. Both happens to run on the Server .

• The ACTION can return a VIEW or ( or a redirect to) another ACTION or simply a FILE
• The VIEW processes a Model ( and a ViewBag/ViewData) and sends the text( HTML) data to the Client .

Instead of PAGES , we will discuss of VIEWS – because the VIEWS sends HTML data to the Client.

So, to transfer data between View1 to View2 in MVC is reduced to this:

a) Page1 transfer data to the server ACTION1( by a,b,c,d methods in the Preamble )

b) The Action receives the values as his parameters ( by binding) and can do this:

b1) Return a different View ( using some logic :

if( a )

return View1(Model1);

else

return View2(Model1);

b2) Returning a Redirect to ACTION2 ( that return View2) or simply return the result of this action

return RedirectToAction(Action2(<parameters>)); //Used in Post/Request/GET, http://en.wikipedia.org/wiki/Post/Redirect/Get

return Action2(<parameters>);

Resuming: Transfer betweem PAGE to PAGE in ASP.NET MVC is really transfering from ACTION to ACTION , besides the cookie that can be transferred directly by the browser.

9 Modalities to transfer data from Page to Page in ASP.NET MVC

Enough theory, let’s do some code. We have a Model to transfer named ModelTransfer

public class ModelTransfer
    {
        public int Age { get; set; }
        public string Name { get; set; }

    }

We have the first View1( Index) and a second View2(Transfer) that will server as an example. Also, we will have the more ACTIONS – one for each example of transfer – all are using the TRANSFER action as an ultimate resort do see the View.

Method1 : Transfer directly to the second View/Action .

<a href='@Url.Action("Transfer", new { Age = 42, Name = "Andrei Ignat" })'>click me</a>

public ActionResult Transfer(ModelTransfer m)

Method2 Index sends POST data to a [HttpPost] Index action, that performs some calculations and return a redirect.Usefull in PRG

@using (Html.BeginForm()) {
<input type="text" id="Age" name="Age" value="42" />
<input type="text" id="Name" name="Name"  value="Andrei Ignat"/>
<input type="submit" value="Click me" />
}

 [HttpPost]
        public ActionResult Index(ModelTransfer m)
        {
            //save to the database the data 

            //this is for transferring alert data - such an "Completed saving" message to the user
            TempData["displayalert"] = " this is from Index POST action!";
            //used in PRG
            return RedirectToAction("Transfer", new ModelTransfer() { Age = m.Age, Name = m.Name });
        }

Method3: No data send. The ServerAction just make some data to be transferred to the Transfer view, by TempData

<a href='@Url.Action("ServerAction")'>click me</a>

 public ActionResult ServerAction()
        {
            //You can put also into the Session / Application /Cache depending on your specifications
            TempData["MyModel"]=new ModelTransfer(){ Age = 42, Name = "Andrei Ignat"};
            TempData["displayalert"] = "this is from Server action!";

            return RedirectToAction("Transfer");
        }

Method4: No data send. The ServerAction just make some data to be transferred to the Transfer view, by Cache

Method5: No data send. The ServerAction just make some data to be transferred to the Transfer view, by Session

Method6: No data send. The ServerAction just make some data to be transferred to the Transfer view, by Application

Method7: No data send. The ServerAction just make some data to be transferred to the Transfer view, by HttpContext Items

Method8: By Cookies

<a href='@Url.Action("TransferCookies")'>click me</a>

 HttpCookie cook = new HttpCookie("Transfer");
            //usually you put here more , but now I do not want to interfere with other methods
            cook.Expires = DateTime.Now.AddSeconds(1);
            cook.Value = "from transfer cookies";
            Response.Cookies.Add(cook);
            return RedirectToAction("Transfer");

Method9: By Javascript /Ajax.
It is an entire post by itself and you can see here:
http://msprogrammer.serviciipeweb.ro/2011/12/05/jquery-ajax-request-and-mvcdetailed/

Summary

In this post you have seen 9 methods to transfer data in MVC. As a bonus, the page dispolays also a message with Javascript( usefull for messaging like “Data Saved to database” messages to the user.
The code source you will find here:

Transfer Data Page to Page
It is made with Razor and MVC3 – but you can replace Razor with aspx and MVC3 with MVC2 also.

If you think I can improve this post, please leave some comment.

_Notes:

_{I used here hard coding values. Please learn about T4MVC and Html.EditorFor !}

_{To learn more about ASP.NET MVC visit http://asp.net/mvc.}

_{Default TempDataProvider is based on Session. There is one more , based on cookies.}

_{Please do the exercises to gain self knowledge about MVC}

It can re-make an object by adding items of “property/value”

It comes in 2 flavors: .NET 2.0 ( reflection ) and .NET 4  ( expression).

Sample Usage:

Sample usage:
var Model = new HydrateGeneric<MyModel>();
Model.AddNewProperty("OneProp", "bb");
Model.AddNewProperty("newData.StartDate", DateTime.Now.AddDays(1).ToString());
Model.AddNewProperty("newData.SecondProp", "AB");
Model.AddNewProperty("newData.aOne.ThirdProp", "XXX");
var data = Model.NewObject();
Console.WriteLine(data.newData.SecondProp);
Console.WriteLine(data.newData.StartDate);
Console.WriteLine(data.newData.aOne.ThirdProp);

It comes from a Paulo Morgado idea from http://msmvps.com/blogs/paulomorgado/archive/tags/ExpressionTrees/default.aspx . However, his initialization does not specify property name – so it’s rather error prone if you do not specify properties + values in right order. I have somewhat improved by

Model. AddNewProperty("OneProp", "bb");

Enjoy!

http://hydrating.codeplex.com/

https://nuget.org/packages/Hydrate

And , if you have used some site intensively, return the favor: Donate back!

For myself it was Wikipedia:

Does not matter the site. Does not matter what they are doing with the money. Do it.

And , again:

Happy New Year And Merry Christmas