Glossary

Glossary

A

abstract class A class that can t be instantiated but that is used as a base from which other classes can be derived. In Microsoft Visual Basic .NET, abstract classes are declared using the MustInherit keyword. In Microsoft Visual C#, abstract classes are declared using the abstract keyword.

abstract member A member of a base class that can t be invoked, but instead provides a template for members of a derived class. In Microsoft Visual Basic .NET, abstract members are declared using the MustOverride keyword. In Visual C#, abstract members are declared using the abstract keyword.

ad hoc testing Testing that relies on the uncoordinated efforts of developers or testers to ensure that code works. This type of testing contrasts with automated testing, which uses test scripts or programs to systematically check that all parts of an application work correctly.

addition The process of combining two or more things.

alias The name you use to identify resources on the Web. Aliases represent physical resources on the Web server, such as a Web form, an HTML page, or a graphic.

application domain The process space within which an ASP.NET Web Forms application runs.

ASP.NET The portion of the Microsoft .NET Framework used to create Web applications and XML Web services. ASP.NET is an evolution of Microsoft Active Server Pages (ASP).

assembly The executable component of an application created using the Microsoft .NET Framework. Web applications, as well as other types of .NET applications, compile their executable code into an assembly file with a .dll file extension. The compiled code consists of IL assembly language (ILAsm), which is then compiled into its final state at run time by the common language runtime (CLR).

authentication The process of determining the identity of a user. In effect, authentication validates that the user is who he or she claims to be.

authorization The process of granting access privileges to resources or tasks within an application. Applications typically authenticate users and then authorize them based on their identities or roles within an organization.

automated testing A type of testing that uses tests written in a scripting or programming language to systematically check that all parts of an application work as expected. Automated testing checks that an application s components work separately (called unit testing), that all components work together (called integration testing), and that changes haven t broken existing features (called regression testing).

B

base class A class that provides properties and methods as a foundation for a derived class. In object-oriented programming, one class can be based on another through inheritance. Using this technique, the base class provides characteristics (such as properties and methods) to a derived class. The derived class can reuse, modify, or add to the base class s members.

behaviors Components that encapsulate specific functionality or actions on a Web form or an HTML page. When applied to a standard HTML element on a page, a behavior modifies that element s default behavior. Behaviors are implemented as styles.

C

caching The technique of storing frequently used items in memory so that they can be accessed more quickly.

cascading See cascading style sheets (CSS).

cascading style sheets (CSS) Web application project files (.css) that collect and organize all of the formatting information applied to elements on a Web form or an HTML page. Because they keep this information in a single location, cascading style sheets make it easy to adjust the appearance of Web applications. Web applications can have multiple style sheets and can switch style sheets at run time to dynamically change the appearance of a Web application.

certificate authority An independent third party that provides server certificates to enable secure communications across the Web through the Secure Sockets Layer (SSL). These server certificates must be purchased and installed on your Web server to use SSL and the HTTPS protocol.

character encoding The method of representing alphanumeric characters as numbers so that a computer can handle strings.

class A data structure that groups properties and methods used to perform tasks in programs. Classes are the fundamental building blocks of object-oriented programs. Objects are instances of classes.

context-sensitive Help A type of Help system in which the topic displayed depends on the current context (or task) within the application.

cookie A small file that a Web application can write to the client s computer. Cookies are used to identify a user in a future session or to store and retrieve information about the user s current session.

CSS See cascading style sheets (CSS).

D

data binding A way to link data (such as a data set) in your application to the properties of a control.

default page A page that Internet Information Services (IIS) displays if the user navigates to the Web application directory without specifying a page to view. IIS uses the name Default.htm and Default.aspx as the default page unless you change it using the IIS property settings for the application.

delegation A programming technique by which a member of one class uses a member from another class to perform some task. Delegation differs from inheritance in that the first class implements a property or method and then calls (or delegates to) the other class s property or method. The two classes do not have to be related to each other in other words, the first class does not have to be derived from the second class.

delegates Types used to invoke one or more methods where the actual method invoked is determined at run time.

deploying Installing an application on the computer where it will run.

derived class A class that is based on another class (called a base class) through inheritance. A derived class inherits the members of its base class and can override or shadow those members.

DHTML behaviors See behaviors.

dirty read The process of reading database records without locking the records being read. This means that an uncommitted change can be read and then rolled back by another client, resulting in a local copy of a record that is not consistent with what is stored in the database.

drivers In the context of testing, drivers are test components that make sure two or more components work together. Drivers are necessary to test components during development when an application is being developed from the bottom up.

E

error See exceptions.

exception handling The process of dealing with unusual occurrences within code so that they do not cause the program to crash or lose data.

exception log A record of exceptions that occurred while an application was running.

exceptions Unusual occurrences that happen within the logic of an application.

F

fragment caching The technique of caching part of a Web form or placing controls or other response items in a user control.

frames Regions of a Web page that you can use to display other Web pages. You use frames to display multiple regions that scroll and behave independently.

G

GAC See global assembly cache (GAC).

global assembly cache (GAC) A special subfolder within the Microsoft Windows folder that stores the shared .NET assemblies. Assemblies stored in the GAC are shared with all other applications installed on the computer.

globalization The process of creating an application that meets the needs of users from multiple cultures.

globally unique identifier (GUID) A 128-bit integer that serves as a unique identifier across networks. GUIDs are used throughout Windows and the .NET Framework to identify components.

GUID See globally unique identifier (GUID).

I

image map A graphic containing multiple regions that the user can click to cause different actions to occur.

impersonation The process of assigning one user identity to another user. ASP.NET uses impersonation to authorize anonymous users to access resources on the Web server. By default, anonymous users impersonate the ASPNET user account.

inheritance The process of basing one class on another. In this process, a base class provides class members to a derived class. The advantage of inheritance is that you can write and maintain code once in the base class and reuse it multiple times in the derived classes.

interfaces In the context of object-oriented programming, an interface is a contract that defines the members that a group of classes provides. Once you implement a particular interface in a class, instances of that class can be used for any argument or variable declared as that interface.

L

localization The process of accommodating cultural differences within an application. Localized applications can support multiple languages, currencies, writing direction, and calendars based on the cultures that they support.

M

managed code Code that runs under the common language runtime (CLR). The CLR takes care of many tasks that would have formerly been handled in the application s executable. Managed code solves the Windows programming problems of component registration and versioning (sometimes called DLL hell) because managed code contains all the versioning and type information that the CLR needs to run the application. The CLR handles registration dynamically at run time, rather than statically through the system registry, as is done with applications based on the Component Object Model (COM).

marshaling The process by which the CLR collects parameters and converts their types whenever a .NET assembly calls an unmanaged procedure.

merge modules Deployment projects for shared components that allow a server to manage the installation of those components so that they re not unnecessarily overwritten and so that they can be safely removed when no longer used.

multiple inheritance The programming technique of deriving a class from two or more base classes. Visual Basic .NET and Visual C# do not support multiple inheritance.

N

namespace collisions The problem that occurs when two items use the same name at a single level of the namespace hierarchy.

neutral cultures Cultures that map to a specific language but not to a specific region.

nodes See XML nodes.

O

One-Click Hosting A feature ASP.NET Web service providers offer that allows developers to upload completed Web applications directly from the Microsoft Visual Studio .NET Start Page s Web Hosting pane.

optimization Writing code in a way that executes more quickly or consumes fewer resources.

overloading In the context of object-oriented programming, the programming technique of providing versions of a method that takes different types of arguments. The ToString method is a good example of an overloaded method.

overriding In the context of object-oriented programming, the programming technique of replacing a member inherited from a base class with a different member in the derived class.

P

platform invoke (pinvoke) The process of executing native code from within a .NET assembly.

process recycling The technique of shutting down and restarting an ASP.NET worker process (aspnet_wp.exe) that has become inactive or is consuming excessive resources.

project The collection of Visual Studio .NET source files that make up an application.

R

regression A problem in which a new or modified component breaks some previously working component. Regression is uncovered during testing.

reproducibility The ability to produce the same result again and again.

S

satellite assembly An assembly file (.dll) that contains localized resources for an application. Each satellite assembly file contains the resources for one culture. An application can have many satellite assemblies, depending on how many cultures the application supports.

save point A point within a database transaction from which you can restore the database state.

scalability The ability to add capacity to an application as user demand increases.

Secure Sockets Layer (SSL) The standard means of ensuring that data sent over the Internet can t be read by others. When a user requests a secure Web page, the server generates an encryption key for the user s session and then encrypts the page s data before sending a response. On the client side, the browser uses that same encryption key to decrypt the requested Web page and to encrypt new requests sent from that page.

SEH See structured exception handling (SEH).

server certificate A file installed through IIS that provides an encryption key for use with the Secure Sockets Layer (SSL). Server certificates are obtained from a certificate authority, which licenses server certificates for a fee and acts as a clearinghouse to verify your server s identity over the Internet.

server controls Visual components used on a Web form to create the user interface of a Web application.

session The sum of interaction between an instance of a client browser and a Web application. A session begins when the browser first requests a resource from within the application. A session ends either when the browser closes on the client s machine or when the session times out after a period of inactivity. (The default is 20 minutes.)

shadowing The programming technique of replacing a member of a base class with a new member in a derived class. Shadowing differs from overriding in that the base class s shadowed member is no longer available from the derived class.

shared members Methods that can be called directly without first creating an instance of a class. These members are called static members in Visual C#.

signature The name, parameter list, parameter types, and return type of a member.

solution A group of Visual Studio .NET projects that make up a single functional unit.

SSL See Secure Sockets Layer (SSL).

Start Page The first Web form displayed when you run a Web application project from within Visual Studio .NET. The Start Page is also the first page the Visual Studio .NET development environment displays in the Document window. This Visual Studio .NET Start Page contains various panes to help simplify some common tasks, such as opening a recent file and making information easier to find.

start-up project The first project Visual Studio .NET starts when you run a multiple-project solution. The start-up project is shown in boldface within the Solution Explorer window.

static members Methods that you can call directly without first creating an instance of a class. These members are called shared members in Visual Basic .NET.

step in Moving from a calling procedure to a called procedure during debugging. Also used in reference to setting breakpoints to stop execution in a specific procedure during debugging.

step over Executing a procedure call as a single statement during debugging.

structured exception handling (SEH) The programming technique of using exception-handling blocks or exception events to handle unusual occurrences in an application.

stubs Nonfunctional components that provide the class, property, or method definition used by another component during testing. Stubs are necessary to test components during development when an application is being developed from the top down.

subweb A virtual folder that contains a Web site.

superclassing The programming technique of deriving a new class from an existing class using inheritance. Superclassing generally refers to a situation in which most of the derived class s behavior and members come directly from the base class.

T

template See XSL template.

testing interface A set of public properties and methods that you can use to control a component from an external testing program.

thread The basic unit to which the server allocates processor time. A single process can have multiple threads.

ToolTip A short, descriptive message that is displayed when a user places the mouse pointer over a control and leaves it there for a couple of seconds. These messages are used throughout Windows applications to provide helpful information about toolbar buttons and other graphical controls whose meaning might not otherwise be obvious.

tracing A programming technique for recording events, such as exceptions, in an application. Tracing is used during debugging and in the testing phase of application deployment.

transaction A group of commands (treated as a single unit) that change the data stored in a database. The transaction ensures that the commands are handled in an all-or-nothing fashion if one of the commands fails, all of the commands fail, and any data that was written to the database by the commands is backed out. In this way, transactions maintain the integrity of data in a database.

tuning The process of making adjustments to a deployed application that don t affect code.

U

unhandled exceptions Exceptions that have not been dealt with in code. Unhandled exceptions cause applications to stop executing and appear to the user as errors in the application.

unmanaged code Code in which the executable itself determines how memory is used. Unmanaged code contrasts with managed code, where memory is allocated and recovered by the CLR.

user control page A Web application project file with the .ascx file extension that combines one or more server controls into a single, visual component that can be used on Web forms.

V

view state The current property settings of server controls on a Web form. By default, ASP.NET automatically maintains view state between postback events.

virtual folder A shared resource identified by an alias that represents a physical location on a server.

W

Web farm A Web application running on multiple servers.

Web form The central user-interface component within a Web application.

Web garden A Web application running on a single server using multiple processors.

wiring an event The process of creating a connection between an object s event and the event procedure that responds to the event.

X

XML nodes Uniquely named elements within an XML file. XML nodes are organized hierarchically with parent-child relationships.

XML schema A description of the data elements contained in the XML file. The XML schema provides the names of the elements, their types, whether they are key fields, and other information.

XSL template An element within an XSL file that provides the information used to format an XML node during an XSL transformation.