ASP.NET Page Execution

  ASP.NET Page Execution  

 When we create an ASP.NET page, we are actually creating the source code for a .NET class. We are creating a new instance of the System.Web.UI.Page class. The entire contents of an ASP.NET page, including all script and HTML content, are compiled into a .NET class.

 When we request an ASP.NET page, ASP.NET Framework checks for a .NET class that corresponds to the page. If a corresponding class does not exist, the Framework automatically compiles the page into a new class and stores the compiled class (the assembly) in the Temporary ASP.NET Files folder located at the following path:

  Web.config 

 \WINDOWS\Microsoft.NET\Framework\v4.0.30128\Temporary ASP.NET Files 

 The next time anyone requests the same page in the future, the page is not compiled again. The previously compiled class is executed, and the results are returned to the browser.Client Web browser request ASPX pages The Web server executes the ASPX page and produce XHTML + CSS + JavaScript response.

STEP 1: Web Client User sends request for the required file to the IIS (Web Server).
STEP 2: IIS will locate the requested file.
STEP 3: If requested file is found, IIS will submit to ASPX Engine.
STEP 4: ASPX Engine will generate a Page Class file, by separating Client side code, Server side code & by adding required methods to execute the server side code.
STEP 5: This Page Class is submitted to Compilers (In case of pre-Compilation is not done).
STEP 6: Compilers will compile the Source Code & will generate MSIL code.
STEP 7: MSIL code will be submitted to CLR. CLR will perform 3 tasks here,
   1. Instantiation: Creates object to the respective Page Class
   2. Processing: Executes the Result/Code
   3. Rendering: Converts the Server side code into Client Understandable format (i.e., HTML and JAVASCRIPT).
STEP 8: CLR will generate complete Execution Result.
STEP 9: Execution Result will be delivered to IIS.
STEP 10: IIS will deliver the result to CLIENT.
Once the Result is delivered to the client, The Object at the Server will be destroyed.

What is a round trip?
 The trip of a Web page from the client to the server and then back to the client is known as a round trip.The complete request and response is called as round trip.