Introducing asp
- 1. • Communication process between browser and server • Web Server / Web Browser’s Role • Understanding the role of HTTP • Creating File System , FTP, Local, Remote HTTP based websites • Anatomy of an ASPX Page • Single-File vs. Code Behind Pages • Website Compilation • Working with Web Configuration Files
- 2. 1. A user uses his or her Web browser to initiate a request for a Web server resource. 2. HTTP is used to send a GET request to the Web server. 3. The Web server processes the GET request on the server (typically locating the requested code and running it). 4. The Web server then sends a response back to the Web browser. The HTTP protocol is used to send the HTTP response back to the Web browser. 5. The user’s Web browser then processes the response (typically HTML and JavaScript) and renders the Web page for display to the user.
- 3. 6. The user may then enter data and perform an action such as clicking a submit button that causes his or her data to be sent back to the Web server for processing. 7. HTTP is used to POST the data back to the Web server. 8. The Web server then processes the POST request (again, calling your code in the process). 9. The Web server then sends a response back to the Web browser. HTTP is used to send the HTTP response to the Web browser. 10. The Web browser again processes the response and displays the Web page to the user.
- 5. • HTTP is a text based communication protocol that is used to request Web pages from Web Server and send the response back to browser • HTTP messages are sent between port 80 or 443 • A typical command looks like this GET /default.aspx HTTP 1.1 Host www.microsoft.com
- 7. • The communication from browser to server is known as REQUEST and that from server to browser is RESPONSE • A Response looks like this : HTTP/1.1 200 OK Server : Microsoft-IIS /7.5 Content-Type: text/html Content-Length: 38 <html><body>Hello </body></html>
- 10. There are two HTTP methods that can be used to submit the form data back to the Web server: GET and POST. When the GET verb is used, the form data is appended to the URL as part of the query string. GET /getCustomer.aspx?Id=123&color=blue HTTP/1.1 Host: www.northwindtraders.com When the POST verb is used, the data is placed into the message body of the request as follows: POST /getCustomer.aspx HTTP/1.1 Host: www.northwindtraders.com Id=123&color=blue
- 12. The typical .aspx page includes three sections: page directives, code, and page layout. Page directives This section is used to set up the environment, specifying how the page should be processed. For example, this is where you can indicate an associated code file, development language, transaction, and more. Code This section contains code to handle events that execute on the server based on the ASP.NET page processing model. Page Layout The Page layout is written using HTML. This includes body, markups and style information
- 13. In the single-file model, the compiler generates a new class for your page. This class inherits from the base Page class. It is typically named with the format ASP.pagename_aspx. This class contains control declarations, event handlers, and related code you have written for your page. The code-behind programming model physically separates your user interface layout markup and your server-side code into two distinct files. In this case the .aspx page contains your layout markup and the related .aspx.cs or .aspx.vb file contains the associated code.
- 14. Most of the Web Applications are not pre-compiled. Instead, pages and codes are typically copied to a Web Server and then dynamically compiled the first time they are requested by a user. Web applications can also be pre-compiled using Build- >Publish Website option in Visual Studio. In this case the entire website is compiled, error checked and only layout code and associated assemblies are copied to the server
- 15. Pro: The entire application need not be recompiled. Only the changed web page is replaced. Con: The first request will be slower and source code is to be deployed to the server
- 16. Pro: Since entire application is compiled and error checked it provides verification that all the pages and their dependencies can be compiled. Performance for the first user request is improved Con: Simply copying the code files is simpler as compared to pre-compilation.
- 17. • Configuration files allow you to manage the many settings related to your Web site. • Each file is an XML file (with the extension .config) that contains a set of configuration elements. The elements define options such as security information, database connection strings, caching settings, and more. • A given site might actually be configured with multiple .config files.
- 18. • Configuration files are applied to an executing site based on a hierarchy. • There is a global configuration file for all sites on a given machine called Machine.config. This file is found in the • %SystemRoot%Microsoft.NETFramework<versionNum ber>CONFIG directory. • The next file in the hierarchy is root default Web.config file located in the same directory • The root directory of each website also contain a Web.config file. • Finally each subfolder can optionally contain its own config file
- 19. Because they are XML files, the configuration files can be opened and modified with any text editor or XML editor. Visual Studio 2008 also provides the Web Site Administration Tool (WSAT), which can be used to modify many of the configuration file settings.
- 20. The WSAT allows you to edit the following categories of the configuration files: Security This setting allows you to set up security for your Web site. In this category, you can add users, roles, and permissions for your Web site. Application Configuration This category is used to modify the application settings. Provider Configuration This configuration file contains settings that allow you to specify the database provider to use for maintaining membership and roles