What does Html.HiddenFor do?

 Creates a hidden input on the form for the field (from your model) that you pass it.

It is useful for fields in your Model/ViewModel that you need to persist on the page and have passed back when another call is made but shouldn't be seen by the user.


Consider the following ViewModel class:

public class ViewModel
{
    public string Value { get; set; }
    public int Id { get; set; }
}

Now you want the edit page to store the ID but have it not be seen:

<% using(Html.BeginForm() { %>
    <%= Html.HiddenFor(model.Id) %><br />
    <%= Html.TextBoxFor(model.Value) %>
<% } %>

Which results in the equivalent of the following HTML:

<form name="form1">
    <input type="hidden" name="Id">2</input>
    <input type="text" name="Value" value="Some Text" />
</form> 

Expose .asmx Web Service to Third Party Clients consuming via Jquery Ajax

Imagine the Following Scenario:

1. http://domain1.com/webservice.asmx
    A .asmx WebService
 
2. http://domain2.com/client.html
    A Client consuming that WebService using Jquery Ajax

STEP 1

PROBLEM
This is a Cross-Domain Request and violates the Same origin Policy.
(which is a security concept for a number of browser-side programming languages)

SOLUTION
A work around is to use JSONP to make the Client Request.
IBM has a Great Article describing This.
Jquery Ajax is described here

STEP 2

PROBLEM
JSONP loads Javascript using <script src=""> element.

In ASP:net  Script files loaded via an HTML <script src=""> element within a browser can only be retrieved via HTTP GET verb requests.
By default ASP.NET  web services layer does not allow web methods to be invoked via the HTTP GET verb.

SOLUTION
To make an ASP.NET AJAX web-method callable via HTTP GET-access, a developer must explicitly attribute each method using ASP.NET's ScriptMethod attribute (and set the UseHttpGet property to true)
[ScriptMethod(UseHttpGet=true)]
Article 1

STEP 3

PROBLEM
The <script> element simply doesn't add content type "application/json; charset=utf-8"  to the request. Yet our JSON WebService is expecting this in the Header of the Request.

SOLUTION

Use a asp.net HTTPModule to filter all requests to the .asmx Webservice and Manually append the correct content type to the Request Header.
Article 1
Article 2


EXAMPLE CODE
Download
1. .asmx Web Service with HTTPModule
2. Jquery Ajax Client 

Setup
Set them both up as Websites in IIS or Apache
with the Client running on default port 80                 http://localhost/jquery-CrossDomainCall-Test.html
and the .asmx Service running on Port 83                http://localhost:83/Service4.asmx
Note you will also need to enable .Net4 for the .asmx Service Website



Same Origin Request
If the client is on the Same Domain as the Web Service
Then we can instead use simple $Jquery.Ajax()
as described in this Great Article

OAuth - Cross-Site Authentication

Nowadays its normal for users to PUSH/PULL data TO/FROM 3rd party Web Applications to your Website.
eg: Facebook LIKE button

USE CASE
1.     A User (or You on behalf of the User) wants to login to their account
        on a 3rd party Web Application and pass data to your Web Application?
eg:  Tweet from your website using their twittername
       Check their Gmail from your website

QUESTION:
Can a user submit their Login Credentials via your WebApp and expect you to securely handle their Sensitive Data?
How does your Web App Authorise & Store their Login Credentials?
How does your website make Requests based on Their Login Credentials?

ANSWER:
OAuth v1 or v2

WIth an OAuth Client connecting to an OAuth Server, we can solve the above USE CASE.

Study the above Diagram for an Overview of OAuth v1
When you're ready to connect to 3rd party Web Apps...read their DOcumentation of their implementation of OAuth since methods and names may change.

Client Side implementation of OAuth
With Browser side code you have no way of PREVENTING people from seeing your Secret 'oauth_consumer_key' and 'oauth_toke_secret'.
StackOverFlow.com Article  StackOverFlow Article 2
Read the following Very Interesting Article for some ideas to solve Client Side OAuth implementation Security Problems. http://derek.io/blog/2010/how-to-secure-oauth-in-javascript/

Note:
You should also understand
SAME-ORIGIN POLICY
SAME-OROGIN POLICY 2
JsonP

Memoization

Once an expensive function runs, it can rewrite itself with an optimized version.

Memoization is a technique similar to caching that takes advantage of

the fact that functions are just data.

var getElement = function() {



    console.log("creating element");

    var element = document.createElement("div");



    // ... Do a bunch of expensive operations



    // Now OVERWRITE this function with a SIMPLER VERSION

    getElement = function() {

        return element;

    };



    return element;

};

The first time getElement runs, it creates the element and runs a bunch
of code with it. Then it rewrites the getElement function to solely return the created element. This makes subsequent calls to getElement much quicker.

Source:  "The JavaScript PocketGuide" - Lenny Burdette 2010

Beautiful HTML - Example

Great Article

Source: http://css-tricks.com/examples/CleanCode/Beautiful-HTML.png

Zend Framework Overview

Here's a Great Diagram

OVERVIEW of ZEND FRAMEWORK 1.x

Research each term mentioned in the Diagram to get an even more in-depth look at the CLASSES and INTERFACES that make up the ZEND FRAMEWORK

Source: The Official Zend Framework Site

Inversion of Control / Dependency Injection

A simple way to decouple classes from what they depend on

"The Framework of Code Classes" calls me rather than me calling the Framework"
This phenomenon is Inversion of Control (also known as the Hollywood Principle - "Don't call us, we'll call you").

EXAMPLE:  Lets say we have a CD Player that takes CD's

One important characteristic of a framework is that the methods defined by the user to tailor the framework will often be called from within the framework itself, rather than from the user's application code. The framework often plays the role of the main program in coordinating and sequencing application activity. This inversion of control gives frameworks the power to serve as extensible skeletons. The methods supplied by the user tailor the generic algorithms defined in the framework for a particular application.

Inversion of Control is a key part of what makes a framework different to a library. A library is essentially a set of functions that you can call, these days usually organized into classes. Each call does some work and returns control to the client.

A framework embodies some abstract design, with more behavior built in. In order to use it you need to insert your behavior into various places in the framework either by subclassing or by plugging in your own classes. The framework's code then calls your code at these points.