asp.net session 19

7/30/2019 ASP.net Session 19

1/35

Slide 1 of 35Ver. 1.0

Developing Web Applications Using ASP.NET

In this session, you will learn to:

Configure a Web server for deployment

Deploy a Web application

Implement tracing in Web applications

Objectives


2/35



Web servers accept requests from Web browsers and

respond accordingly.

To enable a Web server to respond to a browser, you need

to configure it.

The configuration of a Web server involves performing thefollowing tasks:

Creating a virtual directory

Defining Web application URLs

Registering ASP.NET file mappings

Configuring a Web Server for Deployment


3/35



A virtual directory is created so that the user does not get

direct access to the Web application folder residing on the

host computer.

A virtual directory exposes the components of a Web

application to the remote clients and allows them to accessyour Web application through Web browsers.

The Virtual Directory

Let us see how to deploy a website by creating a virtual

directory


4/35



After creating the virtual directory, you can configure the

application pool for your application.

An Application pool can contain one or more applications

and allows you to configure the level of isolation between

different Web applications.You can configure application pools for your Web

applications by using the IIS manager.

For this, you need to right-click the virtual directory that is

created for the Web application and select the Properties

option.You can set the isolation for your application by selecting

the appropriate option from the Application Protection

drop-down list.

The Virtual Directory (Contd.)


5/35



The Properties dialog box provides the following application

protection options:

Low (IIS Process)

Medium (Pooled)

High (Isolated)

The Virtual Directory (Contd.)


6/35



Users access a Web application by using an

easy-to-remember address in the address bar of a Web

browser known as the Uniform Resource Locator (URL).

A URL is the location of a file on the Web and is unique for

every application.To access a Web application, users type the URL for that

application in the address bar of a Web browser.

The Web browser sends this request to the Web server.

The Web server then searches for the application mapped

to that URL and sends it back to the browser.

Web Application URLs


7/35Slide 7 of 35Ver. 1.0


When multiple versions of .NET Framework are installed on

the same computer, each version installs an ASP.NET

Internet Server Application Programming Interface (ISAPI)

extension version associated with it.

The ISAPI extension version determines which version ofthe Common Language Runtime (CLR) will be used by a

particular Web application.

To configure a Web application to use a particular version,

you need to register a script map in the Internet Information

Services (IIS).

Registering ASP.NET File Mappings




A script map is a path to the ASP.NET ISAPI version used

by the application.

When a user requests for a particular Web page, the script

map for the application directs IIS to forward the requested

file to the appropriate version of the ASP.NET ISAPI forprocessing.

To use a particular version of the .NET Framework, you

need to update the script maps so that the request for a

Web page is forwarded to the appropriate version of the

ASP.NET ISAPI for processing.

To update the script map, you need to use the ASP.NET

registration tool called aspnet_regiis.exe.

Registering ASP.NET File Mappings (Contd.)




The process of installing a Web application on a Web server

is known as deployment.

The most basic technique for deployment is to copy the

application components to the hard drive of the Web server.

This type of deployment has the following issues:The application is deployed even if it contains compilationerrors.

The source code of the application is exposed.

The application loads slowly initially because it is compiled

when it is accessed for the first time.

These problems can be resolved by precompiling an

application before deploying it to a Web server.

Deploying a Web Application


10/35Slide 10 of 35Ver. 1.0


Precompilation involves compilation of the source code of

the Web application into DLL assemblies before

deployment.

Advantages of precompiling a Web application are:

Provides faster response timeHelps in identifying the bugs that can occur when a Web page

is requested

Hides and secures the source code of a Web application from

users accessing the application

You can precompile a Web application by using the

aspnet_compiler.exe command-line tool.

Precompiling a Web Application


11/35Slide 11 of 35Ver. 1.0


To compile a website, you need to execute the

aspnet_complier command, as shown in the following

figure.

Precompiling a Web Application (Contd.)


12/35Slide 12 of 35Ver. 1.0


The following table lists some options that can be used with

aspnet_compiler.exe tool.

Precompiling a Web Application (Contd.)

Opt ion Descr ipt ion

-v Specifies the virtual path of the application to be compiled.

-p Specifies the physical path of the application to becompiled.

-u Specifies that aspnet_compiler.exe should create a

precompiled application that allows subsequent updates of

contents such as .aspx pages.

-c Specifies that the application to be compiled should be fully

rebuilt.


13/35Slide 13 of 35Ver. 1.0


The compilation tool of ASP.NET, aspnet_compiler.exe,

compiles the source files and creates separate assemblies

for each source file.

The assemblies are then combined and managed by using

the ASP.NET merge tool, aspnet_merge.exe.

The ASP.NET merge tool can be used to combine:

All assemblies in a precompiled website into a single

assembly.

All Web user interface content assemblies into a single

assembly.

All Web user interface content assemblies into an assembly

for each folder in the website.

Managing ASP.NET Precompiled Output for Deployment


14/35Slide 14 of 35Ver. 1.0


When you use the aspnet_merge tool, without any options,

and only specify the target folder name, as shown in the

following figure, output assemblies are created for each

Web user interface content folder.

Managing ASP.NET Precompiled Output for Deployment (Contd.)


15/35Slide 15 of 35Ver. 1.0


To create a single assembly that combines all Web user

interface content assemblies, you need to use the w switch

with the aspnet_merge tool and specify a name for the

merged assembly, as shown in the following figure.



16/35Slide 16 of 35Ver. 1.0


To create a single assembly that combines all assemblies in

a precompiled website, you need to use the o switch with

the aspnet_merge tool and specify a name for the merged

assembly, as shown in the following figure.



17/35Slide 17 of 35Ver. 1.0



Let us see how to deploy a website by using the Copy Web Site

utility

Let us see how to deploy a website by using the Publish Web Site

utility

Let us see how to deploy a setup project by using a Web Setup

project

Microsoft Visual Studio provides the following methods to

deploy a Web application:

Copy Web Site utility

Publish Web Site utility

Web Setup project


18/35Slide 18 of 35Ver. 1.0


Debugging a Deployed Application

Let us see how to debug a deployed application

You can debug an application even after it has been

deployed to a Web server.


19/35Slide 19 of 35Ver. 1.0


To ensure that the application is working properly and is not

giving unexpected results, you need to keep track of the

execution of your Web application.

ASP.NET provides you with the tracing feature that enables

you to track the program execution, thereby ensuring that

your Web application runs properly.

You can use tracing feature to:

View diagnostic information about a particular Web page.

Display custom tracing information about the execution of an

application.

Implementing Tracing in Web Applications


20/35Slide 20 of 35Ver. 1.0


Tracing can be implemented at any of the following levels:

Page level

Application level

Implementing Tracing


21/35Slide 21 of 35Ver. 1.0


Page-level tracing:

Page-level tracing is used to generate diagnostic information at

the end of page rendering.

The diagnostic information includes all the information about

the requests made to the page and their responses.

To enable page-level tracing, you need to perform the following

steps:

1. Include the following directive at the top of the page:

2. Include the TraceMode attribute in the @ Page directive to

specify the sort order for your trace messages.

Implementing Tracing (Contd.)


22/35Slide 22 of 35Ver. 1.0


The following information is displayed when page-level tracing

is enabled:

Request details

Trace information

Control tree

Session stateApplication state

Request Cookies Collection

Response Cookies Collection

Headers Collection

Response Headers Collection

Form Collection

Querystring Collection

Server Variables



23/35



Application-level tracing:

Application-level tracing is used to trace information for every

Web page in a Web application.

A special page named trace.axd is used to view this trace

information.

To use the trace.axd page, you have to first enable

application-level tracing within the Web.config file for your

application.

You can use the following attributes of the element to

change the tracing settings of your website:

enabledrequestLimit

pageOutput

traceMode

localOnly

mostRecent



24/35



When a Web application is in the development stage, youoften use several Response.Write statements in the

program code to display debugging information, which is

used to troubleshoot the application.

The messages displayed using Response.Write

statements are required for debugging and should not be

displayed to an end user.

The process of tracing enables you to insert debugging

code within an application such that the debugging code

does not need to be removed at the time of deployment.

The Trace property of the Page class returns a Trace

object, which can be used to write custom trace statements.

Writing Trace Information


25/35



The Trace object:

Is an instance of the TraceContext class.

Provides a set of methods and properties that help you to trace

the execution of your application.

The properties of the Trace object are:

IsEnabled: Denotes whether tracing is enabled for the

current request.

TraceMode: Sets the trace modes such as sortByCategory

orsortByTime.

Some of the methods of the Trace object are:

Warn: Displays the trace information in red color.

Write: Displays the trace information in black color.

Writing Trace Information (Contd.)


26/35



Trace listeners are used to:

Collect, store, and route tracing messages.

Redirect the tracing information to logs, windows, or text files.

ASP.NET provides three types of predefined trace listeners:

TextWriterTraceListenerEventLogTraceListener

DefaultTraceListener

Using Trace Listeners


27/35



Adding a trace listener:

To add a trace listener in the web.config file, you need to

include the following markup in the web.config file:

Using Trace Listeners (Contd.)


28/35



To enable ASP.NET to route tracing information to aSystem.Diagnostics listener, you need to include the

following entry in the web.config file:



29/35



Removing a trace listener:

To remove a trace listener from the listeners collection, you

need to include the following markup in the web.config file:



30/35



You can control the tracing output by using trace switches.

Trace switches can be configured to provide filtered tracing

output.

You can also enable and disable certain tracing output using

trace switches.The two types of trace switches are:

BooleanSwitch

TraceSwitch

To initialize a TraceSwitch, you need to first create its object.

The following code snippet shows how you can create andinitialize a TraceSwitch:

System.Diagnostics.TraceSwitch MyTraceSwitch = new

System.Diagnostics.TraceSwitch("MySwitch", "Entire

application");

Trace Switches


31/35



Problem Statement:

Your team leader wants you to implement tracing on the

MusicMania website. You are instructed to display the trace

data for all the Web pages on the MusicMania website. The

trace data should not be displayed on individual Web pages. It

should be displayed on the host Web server for a maximum of50 recent requests. You also need to save the trace data in a

text file.

Activity 14.1: Implementing Tracing


32/35



Solution:

To implement tracing in the MusicMania website, you need to

perform the following tasks:

1. Modify the web.config file.

2. Verify the application.

Activity 14.1: Implementing Tracing (Contd.)


33/35



In this session, you learned that:

The configuration of a Web server involves performing the

following tasks:

Creating a virtual directory

Defining Web application URLs

Registering ASP.NET file mappings

A virtual directory is created so that the user does not get direct

access to the Web application folder residing on the host

computer.

A virtual directory exposes the components of a Web

application to the remote clients and allows them to accessyour Web application through Web browsers.

An Application pool can contain one or more applications and

allows you to configure the level of isolation between different

Web applications.

Summary


34/35



A URL is the location of a file on the Web. It is unique for every

application.

Precompilation involves compilation of the source code of the

Web application into DLL assemblies before deployment.

Precompiling a Web application provides the following

advantages:It provides faster response time because the Web application

does not need to be compiled the first time it is accessed.

It helps in identifying the bugs that can occur when a Web page is

requested. These bugs are rectified at the time of compiling the

Web application. Then the compiled and error-free Web

application is deployed on to the server and is rendered to a user.It hides and secures the source code of a Web application from

users accessing the application.

The compilation tool of ASP.NET, aspnet_compiler.exe,

compiles the source files and creates separate assemblies for

each source file.

Summary (Contd.)

l i b li i i S


35/35


Tracing can be implemented at any of the following levels:

Page level

Application Level

The properties of the Trace object are:

IsEnabled

TraceMode

Some of the methods of the Trace object are:

Warn

Write

ASP.NET provides three types of predefined trace listeners:

TextWriterTraceListenerEventLogTraceListener

DefaultTraceListener

Summary (Contd.)

asp.net session 19

Documents