It does not assume any prior knowledge of ASP, and starts from the ground up. The chapters are organized according to the increasing. What is this book about? ASP is the future of the web. If you're looking for a way to create attractive, intelligent web pages or, if you're just looking for a way to. Beginning Active Server Pages [David Buser, John Kauffman, Juan T. Llibre, Brian Francis, Dave Sussman, Chris Ullman, Jon Duckett] on rattribillvordo.ga
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1. Active Server Pages. 2. Web sites --Design. 3. Web publishing I. Title. .. team of ASP developers that contains some beginning developers. Active Server Pages rattribillvordo.ga - Ebook download as PDF File .pdf), Text File .txt ) A server-side script begins to run when a browser requests rattribillvordo.ga file from Dim intItem 'Repeat the loop until the value of counter is equal to 3. to list the . December , beginning with Version Microsoft officially defines ASP as: “ Active Server Pages is an open, compile-free application environment in which.
Uninstall the entire product' to remove all Sun Java System ASP components and all files and directories under the installation directory. Perform a stage-based uninstall' to select the components to uninstall. Cancel the uninstall' to stop the uninstall without removing any files.
If you chose option '2. Perform a stage-based uninstall,' you are prompted to select the components to uninstall. At the prompts, enter the number of the component s you want removed.
Respond to the prompts as desired, choosing to either proceed with or cancel the uninstall. The guide also provides reference information about using scripting languages, connecting to databases, and developing and using components.
This launches the complete HTML version of guide. Note that the Search box is not functional when the document is accessed in this manner. You can also access the documentation in other ways: From the Administration Console following installation by clicking the 'Documentation' link in the left navigation pane UNIX and Linux only. The index. For more information, see Sending Content to the Browser. Error Handling ASP now has a new error-handling capability so that you can trap errors in a custom error message.
You can use the new Server. GetLastError method to display useful information, such as an error description or the line number where the error occurred. Scriptless ASP Because static content is usually processed more quickly than server-side content it was previously better to assign an. Whenever you needed to add ASP functionality to your static. With this latest release of ASP, however,.
So, if you are creating an evolving Web application in which files may eventually require ASP functionality, you can now conveniently assign those files.
Performance Enhanced Objects Active Server Pages now provides performance enhanced versions of its popular installable components. These objects will scale reliably in a wide range of Web publishing environments. You will be able to share this information across a variety of applications, clients, and servers. Now you can turn your business logic script procedures into reusable COM components that you can use in your Web applications, as well as in other COM compliant programs.
For more information, see Using Components and Objects. When a browser sends a cookie describing its capabilities such a cookie can be installed by using a simple client-side script you can create an instance of the Browser Capabilities Component that retrieves the browser's properties as returned by the cookie.
You can use this feature to discover a browser's capabilities and adjust your application accordingly.
For more information, see Retrieving Browser Capabilities from a Cookie. ASP Self-Tuning ASP now detects when executing requests are blocked by external resources and automatically provides more threads to simultaneously execute additional requests and to continue normal processing.
If the CPU becomes overburdened, ASP curtails the number of threads in order to reduce the constant switching that occurs when too many nonblocking requests are executing simultaneously. For more information, see the metabase property reference for AspThreadGateEnabled.
For more information, see Including Files. Encoded ASP Scripts Traditionally, Web developers have been unable to prevent others from viewing the logic behind their scripts. Web developers can apply an encoding scheme to both client and serverside scripts that makes unreadable the programmatic logic using standard ASCII characters. Encoded scripts are decoded at run time by the script engine, so there's no need for a separate utility. Although this feature is not intended as a secure, encrypted solution, it can prevent most casual users from browsing or copying scripts.
ASP has undergone several important changes and enhancements. If you are updating your application from a previous version of ASP, you should be aware of these changes. In IIS 5. This means that the final output will be sent to the client at the completion of processing or when the script calls the Response. Flush method. For more information, see IsClientConnected. For example, the URLs http: Transaction Flags IIS 4.
However, if an. Execute or Server. Transfer methods, then the transaction flag state is maintained for the second. If the second. Both-Modeled components must aggregate the FreeThreaded Marshaller to be stored in Application state. For IIS 5. In previous versions, the identity assigned to the local server COM object depended on the identity of the user who created the object instance.
CreateObject method. ASP provides a powerful and extensible framework for creating server-side scripts with any COM compliant scripting or programming language. This section is intended to teach the fundamentals of using a scripting language to create an.
You will learn how to accomplish a wide range of basic programming tasks, from creating a loop to manipulating a database and processing transactions. Whether you are a beginning or experienced scripter, you can envision the topics in this section as development goals, that is, as demonstrations intended to encourage you by suggesting more sophisticated ways in which you can utilize ASP.
This can lead to applications that perform better and are more maintainable. Although these topics introduce some scripting and programming concepts, they are not intended to teach you a scripting language. Microsoft scripting languages Microsoft VBScript and Microsoft JScript provide their own documentation, and many additional scripting books are available from your local bookseller.
So, if you are new to scripting, take advantage of the many books, classes, and Internet resources which can help you to master these languages. This section includes:.
Creating an ASP Page: Describes an ASP file and explains how to add script commands to a page. Working with Scripting Languages: Using Variables and Constants: Provides an introduction to using variables in ASP scripts and explains how to access constant definitions. Interacting with Client-Side Scripts: Shows how to write server-side scripts that create and interact with client-side scripts.
Writing Procedures: Describes how to define procedures functions and subroutines and call them from server-side scripts. Working with Collections: Describes how to access items in a built-in object's collections, including access by iterating through a collection. Processing User Input: Explains how to collect and process information gathered from an HTML form.
Using Components and Objects: Explains how to create an instance of an object provided by a COM component, how to use the ASP builtin objects, and how to use the methods and properties of any object. Setting Object Scope: Demonstrates the scope, or extent, of an object and describes how to create session and application scoped objects.
Sending Content to the Browser: Describes how to control the ways in which pages are sent to a browser. Including Files: Explains how to use the include statement to insert the contents of a file into an. Managing Sessions: Describes how to preserve information about a user. Accessing a Data Source: Understanding Transactions: Demonstrates how to run a script under a transaction context. Business and credit card applications often need to the ability to run scripts and components within transactions.
Debugging ASP Scripts: Describes how to use the Microsoft Script Debugger to find and eliminate errors in your scripts. Built-in ASP Objects: Provides a quick overview of the ASP built-in objects, and links to more detailed information. Contains quick reference information about ASP built-in objects.
Developing programmatically advanced collections of scripts called applications; see Developing Web Applications. Designing Web applications; see Design Decisions. A quick way to create an. If your file does not contain any ASP functionality, then the server dispenses with the ASP script processing and efficiently sends the file to the client.
As a Web developer, this affords you tremendous flexibility because you can assign your files. To publish an. Next, request the file with your browser by typing in the file's URL.
Remember, ASP pages must be served, so you cannot request an. After the file loads in your browser, you will notice that the server has returned an HTML page.
This may seem strange at first, but remember that the server parses and executes all ASP server-side scripts prior to sending the file. The user will always receive standard HTML. You can use any text editor to create. Adding Server-Side Script Commands A server-side script is a series of instructions used to sequentially issue commands to the Web server.
If you have previously developed Web sites, than you are probably familiar with client-side scripts, which are used to instruct the Web browser. A delimiter is a character or sequence of characters that marks the beginning or end of a unit.
You can include within the delimiters any command that is valid for the scripting language you are using. The following example shows a simple HTML page that contains a script command: The VBScript function Now returns the current date and time. Commands enclosed by delimiters are called primary script commands. These commands are processed using the primary scripting language.
Any command that you use within script delimiters must be valid for the primary scripting language. By default, the primary scripting language is VBScript. You can also set a different default language. See Working with Scripting Languages. For more information, see Working with Scripting Languages. A statement , in VBScript and other scripting languages, is a syntactically complete unit that expresses one kind of action, declaration, or definition. The conditional If Else statement that appears below is a common VBScript statement.
Depending on the hour, this script assigns either the value "Good Morning! Thus, a user viewing this script before Good Morning! You can include HTML text between the sections of a statement. Else statement, produces the same result as the script in the previous example: Else statement around several lines of HTML text.
The previous example is more useful if you want to display a greeting in several places on your Web page. You can set the value of the variable once and then display it repeatedly. Write "Good Morning! Write "Hello! HTML text with script commands, you can return from within a script command. To return text to built-in object Response. The following example as the previous scripts:. Write sends the text that follows it to the browser.
Use Response. Write from within a statement when you want to dynamically construct the text returned to the browser. For example, you might want to build a string that contains the values of several variables. You will learn more about the Response object, and objects in general, in Using Components and Objects and Sending Content to the Browser.
For now, simply note that you have several ways to insert script commands into an HTML page. You can include procedures written in your default primary scripting language within ASP delimiters. Refer to Working with Scripting Languages file: If you are working with JScript commands, you can insert the curly braces that indicate a block of statements directly into your ASP commands even if they are interspersed with HTML tags and text.
For example: Write "This is the text version of a page. Write "This is the multimedia version of a page. These directives are the output directive and the processing directives. This output directive is equivalent to using Response. Write to display information.
For example, the following directive sets VBScript as the primary scripting language for the page: The processing directive must appear on the first line of an. To add more than one directive to a page, the directive must be within the same delimiter. Do not put the processing directive in a file included with the include statement. You must use a space between the at sign and the keyword. The processing. See Managing Sessions. The LCID keyword sets the locale identifier for the file. See Understanding Transactions.
Important You can include more than one keyword in a single directive. The following example sets both the scripting language and the code page: For all other scripting languages, ASP preserves white space so that languages that depend on position or indentation, are correctly interpreted. White space includes spaces, tabs, returns, and line feeds.
For VBScript and JScript, you can use white space after the opening delimiter and before the closing delimiter to make commands easier to read. All of the following statements are all valid: ASP removes white space between the closing delimiter of a statement and the opening delimiter of the following statement. However, it is good practice to use spaces to improve readability.
Active Server Pages comes with two scripting engines: In addition. If you are already a Visual Basic programmer. Programming languages such as Visual Basic. You can use any scripting language for which the appropriate scripting engine is installed on your Web server. You can set the primary scripting language on a page-by-page basis. In fact. By default. Unlike more complex programming languages.
While interpretation reduces execution efficiency. If you are familiar with another scripting language. A scripting engine is a program that processes commands written in a particular language. You can use any scripting language for which you have a script engine as the primary scripting language. Active Server Pages makes it possible for Web developers to write scripts that execute on the server in variety of scripting languages. You can install and use engines for other scripting languages.
Scripting languages. If you are a Java. Note To use a language that does not support the Object. Active Server Pages Guide Page 15 of Setting the Language for an Application To set the primary scripting language for all pages in an application.
All ASP commands are processed before content is sent to the file: For more information. Follow the guidelines for using an ASP directive. Because scripts written with Active Server Pages are executed on the server. Method syntax as the primary scripting language. Setting the Language for a Page To set the primary scripting language for a single page. The setting for a page overrides the global setting for all pages in the application. The syntax for this directive is: Use Server.
InputBox and MsgBox. CreateObject instead so that ASP can track the object instance. For example. Active Server Pages Guide Page 16 of browser. Write x.
Using Variables and Constants file: When you use JScript keywords in scripts. One consequence of caseinsensitivity is that you cannot distinguish variable names by case. JScript is case sensitive. These characters should be used on each comment line. This script will work. Unlike HTML comments. This script will fail. Declaring and Naming Variables Follow the rules and guidelines of your scripting language for naming and declaring variables.
Even if you are not required to declare a variable before using it. To declare a variable. To declare a variable in VBScript. Declaring a variable means telling the script engine that a variable with a particular name exists so that you can use references to the variable throughout a script.
A variable is a named storage location in the computer's memory that contains data. JScript Although JScript does not usually require variable declarations. The data contained in a variable is called the variable's value. For more information on these commands. Variables give you a way to store. JScript will assume that that you referring exclusively to the global variable. For more information on the var statement. A variable declared outside a procedure has global scope. It cannot be accessed by anything outside the procedure.
If you do not declare variables. A variable declared inside a procedure has local scope. When the procedure call sets Y to 2. Note Limiting variable scope to a procedure will enhance performance. In this case. Variable Scope The scope. If you declare variables. Modifying the value of one will not modify the value of the other.
Application-scoped variables are available to all pages in one ASP application that are requested by any user.
It is easy to forget that you must use different names for variables used in the main script and in the included script unless you declare the variables. To make a variable accessible beyond a single page. Session-scoped variables are available to all pages in one ASP application that are requested by one user. The included script is contained in a separate file but is treated as though it were part of the including file.
The following example uses the output directive to display the current value of Session "FirstName": This is particularly important if you use the include statement to include files into your. Session Scope To give a variable session scope. You can also create object instances with session or application scope.
ASP provides two built-in objects into which you can store variables: Session variables are a good way to store information for a single user. Application variables are a good way to store information for all users of a particular application.
Using Constants A constant is a name that takes the place of a number or string. To declare a type library. Active Server Pages Guide Page 20 of those preferences to determine what page to return to the user. A component can declare constants in a component type library. Once you have declared a type library in your.
The following example uses the output directive to display the value of Application "Greeting": Some of the base components provided with ASP. Application Scope To give a variable application scope.
Write to access the named entry from any subsequent page in the application. In previous versions of ASP.
The use of the include directive to include constant definitions is still supported. Components might not provide constant definition files in future releases of ASP. Recordset" rstCustomerList.
In the following example. If you want to use your constants on more than one. ASP's effectiveness can be extended by using it to generate or manipulate client-side scripts. In VBScript. In JScript. Defining Procedures file: You can define your own procedures and call them repeatedly in your scripts. You can place procedure definitions in the same.
Innovative use of this technique can also reduce round-trips and server processing. A procedure is a group of script commands that performs a specific task and can return a value. Calling Procedures To call procedures. Commands that are not part of a procedure may cause unpredictable results because these commands may be executed in an uncertain order.
Write "You called MyFunction. The commands in the script block must form one or more complete procedures in the chosen scripting language. You can specify any language for which you have the scripting engine installed with the server. If you do not set this attribute. To specify JScript.
To specify VBScript. Write to send content to the browser. The following example illustrates creating and calling procedures by using two different scripting languages VBScript and JScript. If you use Call syntax to call any built-in or user-defined function. If you omit the Call keyword. Indexed access is generally used to iterate through a collection. You can access an item in a collection by its unique string key.
If an item with a particular name appears only once in an object's collections. The position of an item will also move as the collection is modified. Collections are data structures similar to arrays that store strings. ASP searches the collections associated with an object in a particular order. It can also hold any objects instantiated by calling Server.
Suppose you have stored the following user information in the Session object: Most of the ASP built-in objects provide collections. Accessing an Item by Name or Index You can access a specific item in a collection by referencing its unique string key. The index associated with an item might change as items are added to or removed from the collection. You can also use a shorthand notation to access items by name.
Unlike arrays. Next statement. Contents Response. Write Session. Iterating through a Collection You can iterate through all the items in a collection to see what is stored in the collection or to modify the items. For the Request object. Dim strItem 'For each item in the collection.
You use the Count property to specify the end value of the counter. For Each strItem In Session. Active Server Pages Guide performance: Count 'Repeat this loop until the counter equals the number of items 'in the collection. Dim intItem 'Repeat the loop until the value of counter is equal to Each statement to access the items you stored in the Session object: You must supply the collection name when you iterate through a collection.. ASP supports the Count property for a collection.
Dim lngItem. The moveNext method moves to the next item in the collection. For greater efficiency when using the Count property with a JScript for statement.
The Cookies collection of the Request and Response objects can thus hold multiple values in a single item. Cookies collections. The following example demonstrates this technique: Subkeys are supported only by the Request. These subitems. Cookies supports only read operations. The following creates a regular cookie and a cookie with a subkeys: Cookies and Response. Cookies supports only write operations. The atEnd method indicates whether there are any more items in the collection.
That way. For Each Cookie In Request. HasKeys Then Response. Cookies "User" file: Write Cookie If Request. This technique is demonstrated in the following example. Cookies Cookie. You can avoid this situation by first checking to see whether a cookie has subkeys by using the HasKeys attribute of the Cookies collection. Cookies Response.
Dim Cookie. Cookies Cookie Response. You can also enumerate all the cookies in the Request. Cookies collection and all the subkeys in a cookie. For Each Subkey In Request. Subkey 'Display the entire cookie collection.
When you iterate through a collection that contains objects. Cookies "UserId". They do not support the Add method. For more information about instantiating objects in this manner.
StaticObjects Response. The QueryString collection was first to define the case of this key. Iterating through a Collection of Objects The Session and Application collections can hold either scalar variables or object instances.
Examine the following script: The Contents collection holds both scalar variables and object instances created by calling Server. Because references to collection values are independent of the case of the key name. QueryString "User" Page 30 of The case of the key name is set by the first collection to assign a value to the key.
You could iterate through the StaticObjects collection to retrieve object properties: When the user submits HTML information. Once again. Text boxes. COM components. In this topic you will not only learn how to create basic form processing scripts. The form also contains an hidden input tag not displayed by the Web browser that you can use to pass additional information to a Web server.
Using the ASP Request object you can create simple. Write "This is your first visit to this Web site! A static. You are 30 years old! This is your first visit to this Web site!
The QueryString collection also has an optional parameter that you can use to access one of multiple values that appear in the URL request using file: The first two methods operate in the same way as forms that interact with other Web server programs. The third method is a particularly useful and will be demonstrated in the Validating Form Input section.
Hello Clair Hector. Count To display the multiple values types. If you need to send a large amount of information from a form to a Web server. The Form collection stores values in a manner similar to the QueryString collection. QueryString "Food". Write Request. You can also use the Count property to count the number of times that a specific type of value appears.
Apples Olives Bread You can also display the entire list of values as a comma-delimited string by using the following: Some Web servers tend to restrict the size of the URL query string. The POST method. The following client-side script validates user—input in this case.
In general. Form "Food". Validation scripts can check for such things as whether the user entered a valid number or whether a text box was left empty. Imagine that your Web site includes a form that enables users to compute the rate of return on an investment. You will probably want to verify whether a user has actually entered numerical or text information in the appropriate form fields.
Beyond prompting users more quickly about input errors. A particularly advantageous way of carrying out server-side validation is to create a form that posts information to itself. Important If your are using JScript for server-side validation. That is. The input is returned to the same file. Users who do not immediately understand this information may become frustrated. Using this method of processing and validating user input can greatly enhance the usability and responsiveness of your Web based forms.
Web-based forms forward requests to a separate Web page containing error information. Transfer "Complete. Form "Password". The following script illustrates the correct way to assign variables with JScript: If you are new to scripting.
ASP comes with base components that you can use immediately. ASP also provides a set of base components that you can use to greatly enhance your scripts. Form "Name" 1. Components provide functionality that you use in your scripts to perform specialized tasks.
COM components are the key to building powerful. COM components execute common tasks so that you do not have to create your own code to perform these tasks.
Active Server Pages Guide Page 36 of local variable. Form "Name". Without parenthesis. Write "Your name and password are different. Write "Your name and password are the same. Components can be combined with other components even across networks to create a Web application. The Ad Rotator component provides one object. Additional components can also be obtained from thirdparty developers.
For the base components provided with ASP. Each object has methods programmed procedures and properties behavioral attributes. Components provide one or more objects. COM components are also known as Automation servers. If you are familiar with COM programming.
Because the verification is isolated from the order process. To use an object provided by a component. Use the ASP Server. To run on the Web server. Visual Basic. Once you have installed a component on your Web server. When you create the object instance. If you are a Web application developer. Microsoft's powerful scripting technology that you can use to create COM components.
The following is an example of a Windows Script Components. ASP cannot track your use of the object in your scripts. You must use the ASP Server.
To use this Windows Script Component in a Web page. Method parameters file: CreateObject "ConvertTemp. The syntax for calling a method is: These objects are automatically created for you when the ASP request starts processing.
Unlike using the objects provided by a COM component. Calling an Object Method A method is an action you can perform on an object or with an object.
For a complete description of the built-in objects. See Working with Scripting Languages for more information. Properties define object characteristics. Property You can sometimes read and set the value of a property. If your language does not. CreateObject to create an instance of a Java class. To instantiate a class with monikers. You can then use Server.
Setting an Object Property A property is an attribute that describes the object. The syntax is: Method syntax. The following expression specifies no border: CreateObject can also access the ASP built-in objects and participate in a transaction.
The scope of an object determines which scripts can use that object. If you must create objects in a loop. Any script command in the same ASP page can use a page-scope object. You can change the scope of an object. To use Java monikers. Thus an object has the scope.
Creating Objects in Loops In general. This topic explains how to work with page scope objects and how to change the scope of objects. The recommended scope for most objects is page scope. The object is accessible to any script commands on that page. The following example creates a sessionscope instance of the Browser Type object of the Browser Capabilities component: Giving an Object Application Scope file: CreateObject method for session-scope objects.
CreateObject method to store an object in the Session built-in object. To give an object session scope. The following example stores an instance of the Browser Type object in the Session object.
Session scope is used for objects that are called from multiple scripts but affect one user session. CreateObject method instantiates the object immediately.
The Server. You should give objects session scope only when needed. If you do use session scope. In the Global. Active Server Pages Guide Page 42 of Giving an Object Session Scope A session-scope object is created for each new session in an application and released when the session ends. CreateObject method on an ASP page to create a session scope object instance. Performance Issues in this topic. Some utility objects. To give an object application scope.
This object is shared by all client requests. GetAdvertisement "CustomerAds. CreateObject method in an. In many cases. Active Server Pages Guide Page 43 of An application-scope object is a single instance of an object that is created when the application starts.
CreateObject to store an object instance in the Application built-in object. Session scope objects Objects marked Both will give you the best performance. User-defined JScript objects are supported in ASP server-side scripts and work well when they have page scope.
Page scope objects Objects marked Both or Apartment will give you the best performance. CreateObject method to store objects marked Both in the Application object. For more information about scoping variables. Using single-threaded or apartment-threaded objects will cause the Web server to lock the session down to one thread. Freethreaded objects do not lock down the session. Advanced Information: Performance Issues The threading model of a component may affect the performance of your Web site.
The object instance is created when your script uses the new operator to invoke the constructor. Because you may not always have control over the threading model of the objects you use.
In this way. CreateObject method to store objects in the Session object. User-Defined JScript Objects You can create your own JScript object by defining a constructor function that creates and initializes the properties and methods of the new object.
In particular. Application scope objects Objects marked Both. Active Server Pages Guide Page 44 of objects is to use session or application scope variables that pass information to objects created at the page level. You can. Write to send content back to the user. Active Server Pages Guide Page 45 of For more information on threading models and their implications for component performance. You can also explicitly send content to the browser by using the Response object. Content that is not within scripting delimiters is sent directly to the browser.
As a script in an ASP page is processed. Write when you do not want to break up a statement with delimiters or when you want to build the string that is returned to the browser. These file types may be used as a reference when you choose to manually set the content type with ASP. Redirecting the Browser Instead of sending content to a user. Setting the Content Type When the Web server returns a file to a browser.
Redirect "Register. This enables the browser to determine whether it can display the file itself or whether it has to call another application. To see the content types already defined by your Microsoft Web server. Redirect does not need to be followed by Response. Transfer to jump between the pages of an application depending on state information: ASP enables you to turn buffering on or off.
Place the Response. Transfer you can directly transfer requests for. Request information is then made available to the destination file when it begins execution. During execution. Redirect statement at the top of the page.
Redirect to redirect a browser requires a round-trip. Active Server Pages Guide Page 47 of server-side scripts which are processed before any content is sent to the user are said to be buffered. If you use Response. With Server. The server then adds this request to the request queue along with other client's requests that arrived in the meantime.