Transcript About the Presentations - School of Information Technology

About the Presentations
• The presentations cover the objectives found in
the opening of each chapter.
• All chapter objectives are listed in the beginning
of each presentation.
• You may customize the presentations to fit your
class needs.
• Some figures from the chapters are included. A
complete set of images from the book can be
found on the Instructor Resources disc.
ASP.NET Programming
with C# and SQL Server
First Edition
Chapter 1
Introduction to Web
Development
Objectives
In this chapter, you will:
• Study the history of the World Wide Web
• Learn about Web development
• Learn about Microsoft Visual Web Developer 2008
Express Edition
• Work with well-formed Web pages
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Introduction to Web Development
• Original purpose of the World Wide Web was to
locate and display information
• With increasing commercial usage came demand
for more interactive and visually appealing Web
sites
• Initial response was JavaScript, but it has some
disadvantages:
– Runs on the client’s system
– Works only within a Web browser
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Introduction to Web Development
(cont’d.)
• For a fully interactive Web site that accesses a
database on a server, you must use a server-side
scripting tool such as ASP.NET
– Combined with C#, ASP.NET is one of today’s most
popular Web site development technologies
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Introduction to the World Wide Web
• Internet: a vast network that connects computers
all over the world
• Originally developed in the 1960s by the Advanced
Research Projects Agency (ARPA) of the U.S.
Dept. of Defense (later known as DARPA)
– Goal: to interconnect the main computer systems of
various universities and research institutions funded
by ARPA
– First implementation was called ARPANET
– Access was restricted to academic researchers,
scientists, and the military
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Introduction to the World Wide Web
(cont’d.)
• At the end of the 1980s, commercial access to the
Internet was granted
• World Wide Web (or Web): created by Tim
Berners-Lee in 1990-91 at the European
Laboratory for Particle Physics (CERN) in Geneva,
Switzerland
– Purpose: to easily access cross-referenced
documents, through a method called hypertext
linking
• Hypertext link (hyperlink): contains a reference to
a Web page that can be accessed by a click
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Introduction to the World Wide Web
(cont’d.)
• Web page: a document on the Web
• Uniform Resource Locator (URL): a unique
address on the Web
• Uniform Resource Identifier (URI): a generic term
for many types of names and addresses on the
Web
• Web site: refers to a location on the Internet of
Web pages and related files that belong to a
company, organization, or individual
• Web browser: a program for displaying Web pages
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Introduction to the World Wide Web
(cont’d.)
• Request: when the user’s browser asks a Web
server for a Web page
• Web server: a computer that delivers Web pages
• Response: what the Web server returns to the
Web browser
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Understanding Web Browsers
• Microsoft Internet Explorer: currently the most
popular browser on the market
• NCSA Mosaic: first browser, created in 1993
• Netscape Navigator: created in 1994, and
controlled 75% of the market until Internet Explorer
was released, starting the “browser wars”
• Incompatibilities among browsers for DHTML
elements resulted in creation of a set of industry
standards
• World Wide Web Consortium (W3C) oversees
development of standards for the Web
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Understanding Web Browsers (cont’d.)
• A benefit of the browser wars was rapid
development and adoption of advanced Web page
standards, including JavaScript, CSS, and DHTML
• Mozilla Firefox: a new open source software
browser that has gained significant market share
• Open source: software for which the source code
can be freely used and modified
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Using HTML
• Hypertext Markup Language (HTML): a markup
language used to create Web pages (HTML
pages)
• Markup language: a set of characters or symbols
that define a document’s logical structure – how it
should be printed or displayed
• HTML is based on Standard Generalized Markup
Language (SGML)
• HTML documents are text documents that contain
formatting instructions called tags
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Basic HTML Syntax
• HTML tags: determine how data is displayed on a
Web page
–
–
–
–
Are enclosed in brackets (< >)
Usually occur as an opening and closing pair of tags
Closing tag starts with a / to define it as a closing tag
Data may be placed within the tag pair
• Element: a tag pair and any data it contains
• Content: the information contained within an
opening and closing tag
• Empty element: an element that does not require
a closing tag
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Basic HTML Syntax (cont’d.)
Table 1-1: Common HTML elements
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Basic HTML Syntax (cont’d.)
• Root element: contains all other elements in a
document
• <html> element: the root element for an HTML
document
• <head> element: contains information used by the
browser
– Occurs at the beginning of an HTML document after
the opening <html> tag
• <title> element: contains text that appears in the
browser’s title bar
– <head> element must contain a <title> element
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Basic HTML Syntax (cont’d.)
• Document head: the <head> element and its
contents
• <body> element: contains the document body
• Parsing (or rendering): the process by which a
Web browser assembles and formats an HTML
document
• HTML is not case sensitive, but it is recommended
to use lowercase letters for all elements
• Attributes: parameters used to configure some
HTML elements
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Basic HTML Syntax (cont’d.)
• Attributes are placed in the opening tag, prior to the
closing bracket
– Syntax: attribute = “value”
• Only recognized HTML elements and text are
processed by a browser
– Nonprinting characters such as tabs and line breaks
are ignored
• <p> element: creates a paragraph with a line break
before and after its contents
• <br> element: creates a line break
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Creating a Web Page
• HTML documents are text files
– Can be created with any text editor, such as
Notepad or WordPad
– Cannot view the final result until the document is
opened in a browser
• HTML editor: an application designed for creating
HTML documents
• Examples: Macromedia Dreamweaver, Microsoft
FrontPage
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Web Communication Protocols
• Hypertext Transfer Protocol (HTTP): manages
the hypertext links used to navigate the Web
• Host: a computer system that is being accessed by
a remote computer
• Domain name: a unique address for identifying a
Web server on the Internet
• Domain identifier: last part of a domain name that
identifies the type of organization
• URL may also contain directory and file names
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Web Communication Protocols
(cont’d.)
Figure 1-3 Sample URL
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Web Communication Protocols
(cont’d.)
• Transmission Control Protocol/Internet
Protocol (TCP/IP): a large collection of
communication protocols used on the Internet
– HTTP is a component of TCP/IP
• Hypertext Transfer Protocol Secure (HTTPS):
provides secure Internet connections
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Introduction to Web Page
Development
• Web page design (Web design): refers to the
visual design and creation of documents on the
Web
– Quality Web design plays an important role in
attracting first-time and repeat visitors to a Web site
• Web page authoring (Web authoring): refers to
the creation and assembly of tags, attributes, and
data that make up a Web page
• Web development (Web programming): refers to
the design of software applications for a Web site
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Understanding Client/Server
Architecture
• Server: usually refers to some sort of database
from which a client requests information
• Two-tier system: a system consisting of a client
and a server
• Client (front-end):
– Handles the presentation of the interface to the user
– Receives, formats, and presents the results returned
from the server
• Server (back-end): performs the heavy processing
such as calculations
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Understanding Client/Server
Architecture (cont’d.)
Figure 1-4 The design of a two-tier client/server system
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Understanding Client/Server
Architecture (cont’d.)
• Three-tier (multitier) client/server system:
contains three distinct pieces:
– Client tier: the Web browser
– Processing tier: handles the interaction between
the Web browser client and the data storage tier
– Data storage tier: stores data in a database and
handles requests from the processing tier
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Understanding Client/Server
Architecture (cont’d.)
Figure 1.5 The design of a three-tier client/server system
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Client-Side Scripting and JavaScript
• Static Web pages: pages that cannot change after
the browser renders them
• JavaScript: client-side scripting language used to
develop interactive Web pages
• Client-side scripting: refers to a scripting
language that runs on the user’s browser (on the
client tier)
• Scripting language: refers to any type of language
capable of programmatically controlling a Web
page
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Client-Side Scripting and JavaScript
(cont’d.)
• Scripting engine: part of the browser that
executes scripting language code
• Interpreter: any program that executes scripting
language code
• Scripting host: a Web browser that contains a
scripting engine
• JavaScript allows creation of:
–
–
–
–
Web pages with interactive games
Dynamic modification of Web pages after rendering
Visual effects such as animation
Control of the Web browser window
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Client-Side Scripting and JavaScript
(cont’d.)
• For security reasons, client-side JavaScript:
– Cannot be used outside of a Web browser
– Does not allow file manipulation
– Does not include mechanisms for creating network
connections or accessing databases
– Cannot run system commands or execute programs
on a client
– Cannot interact directly with Web servers operating
at the processing tier
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Server-Side Scripting and ASP.NET
• Server-side scripting: a technology that
processes a request by executing a script on a
server
– Primarily used for communication between the client
tier and the data storage tier
– Common uses include shopping carts, search
engines, message boards, Web-based e-mail, blogs,
games, etc.
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Server-Side Scripting and ASP.NET
(cont’d.)
Figure 1.6 How a Web server processes a server-side script
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Server-Side Scripting and ASP.NET
(cont’d.)
• Active Server Pages (ASP).NET: server-side
scripting technology; part of Visual Web Developer
– Can use two languages with ASP.NET: Visual Basic
or Visual C#
• C#: an object-oriented programming language
based on the C++ programming language
• Object-oriented programming (OOP): refers to
the creation of reusable software objects that can
be incorporated into other programs
• .NET Framework: Microsoft platform for developing
Web applications
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Should You Use Client-Side
or Server-Side Scripting?
• Use client-side scripting for:
– Controlling the Web browser
– Input data validation
– Light processing
• Use server-side scripting for:
– Accessing a database
– Performing intensive calculations
– Using data storage
• Web application: program that runs on a server but
is accessed by clients through a Web page on a
browser
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Introduction to
Microsoft Visual Studio 2008
• Visual Studio: a suite of development tools
including Visual C++, Visual C#, Visual Basic, and
Visual Web Developer
• Express Editions: free but limited editions of the
tools in Visual Studio
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Installing Microsoft Visual Web
Developer 2008 Express Edition
• Visual Developer can be used to create:
–
–
–
–
–
–
ASP.Net Web sites
HTML pages
Cascading Style Sheets
XML files
JavaScript code
Other types of files used on a Web site
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Managing Web Sites
in Visual Web Developer
• To create a new Web site, use File menu – New
Web Site, then select the type from the templates:
–
–
–
–
ASP.NET Web site
ASP.NET Web service
Empty Web site
WCF (Windows Communication Foundation) Web
service
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Managing Web Sites
in Visual Web Developer
• To add a new item to a Web site, use Website
menu – Add New Item
– Select item type from the list of installed
templates
• To add an existing item, use Website menu –
Add Existing Item
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Figure 1.7 Add New Item dialog box
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Managing Web Sites
in Visual Web Developer (cont’d.)
• Web site’s project settings are stored in two files:
– Visual Studio Solution file (.sln): contains settings
required by the project
– Solution User Options file (.suo): contains
customization options for the project
• These files are stored in the project folder
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Using the Visual Studio Integrated
Development Environment (IDE)
• Integrated development environment (IDE):
the Visual Studio workspace in which you
create projects
• Project: the program you are writing (or the
Web site you are developing)
• Solution: can contain multiple projects
• Start Page: contains links to recent projects,
tutorials, developer information, and recent
news about Visual Web Developer
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Figure 1.8 IDE Start Page
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Using the Visual Studio Integrated
Development Environment (cont’d.)
• Solution Explorer window: used to manage the
files associated with the Web site
– Provides a hierarchical list of the project files
• Code Editor: used to edit programming code
– Includes statement completion IntelliSense
technology to automate tasks
• Text Editor: used to edit text that is not associated
with a programming language
• CSS Editor: used to edit CSS files
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Figure 1.9 Solution Explorer window for the Cessna project
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Figure 1.10 Statement completion in the Code Editor
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Using the Visual Studio Integrated
Development Environment (cont’d.)
• Properties window: used to change
properties, attributes, and other settings
associated with a project
– Contains two columns: property column and value
column
• Certain types of windows in the IDE can be floating
or dockable
– Right-click the window’s title bar to change between
floating and dockable
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Figure 1.11 Properties of the <form> tag displayed in the Properties window
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Figure 1.12 Solution Explorer window with its dockable property turned on
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Figure 1.13 Solution Explorer window with its floating property turned on
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Building and Starting a Web Site
• Source code: original programming code
• Compile: to process and assemble the source
code into an executable format
• Use Build menu to compile source code
– Build page: compiles an individual file
– Build Web Site: compiles all source files
• Visual Web Developer automatically saves
changes to all open items during the build process
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Building and Starting a Web Site
(cont’d.)
• Output window: displays status messages for
various IDE features, such as build progress
– Use View menu – Output to display the Output
window
• Error List window: lists any source file errors
found during the build process
– Use View menu – Error List to display this window
• Compiler error messages: show any syntax
errors in a source file
• Warning messages: occur for potential problems
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Figure 1.14 Output window after building the Cessna Web site
Figure 1.15 Error List window displaying errors found in ASP.NET source file
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Using the ASP.NET Development
Server
• ASP.NET Development Server: basic Web server
that can be used to test a Web site on your local
computer
– Designed to run under localhost, the name used by
a computer to refer to itself
– Use Debug menu – Start Without Debugging
• Port: represents the endpoint of a connection
between a client and a server
– Port 80 is reserved for HTTP communications
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Working with Well-Formed Web Pages
• Current version of HTML is 4.01, released in 1999
• Extensible Hypertext Markup Language
(XHTML): replaced HTML for Web pages
– Supports devices other than traditional Web
browsers
• User agent: an application capable of retrieving
and processing HTML and XHTML documents
– Includes mobile phones, PDAs, browsers, search
engine crawlers, etc.
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XHTML Document Type Declarations
(DTDs)
• Well-formed document: one that conforms to the
rules and regulations of XHTML
• Must include a <!DOCTYPE> declaration as the
first line of an XHTML document
• Document type declaration (DTD): defines the
elements and attributes that can be used in a
document
• Deprecated: term for elements and attributes that
are considered to be obsolete
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XHTML Document Type Declarations
(cont’d.)
Table 1.2 HTML elements that are deprecated in XHTML 1.0
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XHTML Document Type Declarations
(cont’d.)
• Three types of DTDs for XHTML documents:
– Transitional DTD: allows you to use deprecated
style elements
– Frameset DTD: identical to transitional DTD, but
also includes the <frameset> and <frame> elements
– Strict DTD: eliminates elements that were
deprecated in the transitional and frameset DTDs
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Writing Well-Formed Documents
• A well-formed document:
– Must include <!DOCTYPE> declaration and <html>,
<head>, and <body> elements
– Must use <html> as the root element
– Is case sensitive
– Must have closing tags for all XHTML elements
– Must close all empty elements with a space and
slash before the closing bracket
– Must properly nest XHTML elements (an element
must be totally contained within another element)
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Using Phrase Elements
• XHTML uses two types of inline elements for
formatting text:
– Formatting elements: provide specific instructions
about how their content should be displayed
– Phrase elements: primarily identify or describe their
content
• Recommended to use phrase elements to allow
compatibility with different user agents
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Using Phrase Elements (cont’d.)
Table 1.3 Phrase elements
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Working with Cascading Style Sheets
(CSS)
• Style: a single piece of CSS formatting information
• CSS information can be added directly to
documents or stored in separate documents
shared by multiple Web pages
• CSS design and formatting techniques are
independent of the content of a Web page
• Style declaration: creates a CSS style; consists
of:
– Property: refers to a specific CSS style
– Value: determines the style’s visual characteristics
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Working with Cascading Style Sheets
(cont’d.)
• Three locations for style declarations:
– Inline styles: add style information to an individual
HTML element, using a style attribute
– Internal style sheets: add style information to an
entire document, using <style> elements within the
document head
• Selector: the element to which a specific style rule
applies
– External style sheets: separate text documents
with style declarations that are used by multiple Web
documents in a Web site
• Have a file extension of .css
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Validating Web Pages
• Validating parser: program that checks whether
an XHTML document is well formed
• Validation: process of verifying that an XHTML
document is well formed and conforms to the
specified DTD
• W3C Markup Validation Service: free service to
validate both HTML and XHMTL
• Visual Web Developer automatically validates Web
pages
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Summary
• World Wide Web created by Tim Berners-Lee in
1990-91 at CERN
• W3C established in 1994 at MIT to develop Web
standards
• Two-tier system consists of client and server
• Three-tier system consists of client, processing,
and data storage tiers
• JavaScript is a client-side scripting language
• Active Server Pages (ASP).Net is a server-side
scripting technology
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Summary (cont’d.)
• Visual Studio is an integrated development
environment (IDE) including Visual C++, Visual C#,
Visual Basic, and Visual Web Developer
• Visual Web Developer includes the ASP.NET
Development Server for testing Web sites
• XHMTL is the current standard markup language
for Web pages
• A document type definition (DTD) defines the
elements and attributes that can be used in a
document
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Summary (cont’d.)
• Use CSS to design and format the display of Web
pages
• A validating parser is a program that checks
whether an XHTML document is well formed
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