Getting Started Building ColdFusion MX Applications
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CONTENTS ABOUT THIS BOOK . . . . . . . . . . . . . . . . . . . . . . . . . . . VII Developer resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii About Macromedia ColdFusion MX documentation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix Printed and online documentation set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix Viewing online documentation. . . . . . . . . . . . . . . . . . . . .
Processing form data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 Form processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 Commenting your code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28 CHAPTER 3 Database Fundamentals . . . . . . . . . . . . . . . . . . . . . . . 29 Understanding database basics . . . . . .
LESSON 3 Creating a Main Application Page . . . . . . . . . . . . . . . . 81 Enhancing the Trip Maintenance application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .82 Showing additional trip details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84 Avoiding the potential security risk when using dynamic SQL . . . . . . . . . . . . . . . . . . . . .88 Linking the Search Results page to the Trip Detail page . . . . . . . . . . . . . . . . .
vi Contents
ABOUT THIS BOOK Getting Started Building ColdFusion MX Applications is intended for anyone who wants to learn how to use ColdFusion MX to create web applications. This book consists of two parts: • Part I introduces related web technologies and explains how ColdFusion works. This part also introduces the ColdFusion Markup Language (CFML), basic database concepts, and information about how to configure your development environment for the tutorial in Part II of this book.
Developer resources Macromedia, Inc. is committed to setting the standard for customer support in developer education, documentation, technical support, and professional services. The Macromedia website is designed to give you quick access to the entire range of online resources. The following table shows the locations of these resources: Resource Description URL Macromedia website General information about Macromedia products and services http://www.macromedia.
About Macromedia ColdFusion MX documentation The ColdFusion documentation is designed to provide support for the complete spectrum of participants. The print and online versions are organized to let you quickly locate the information that you need. The ColdFusion online documentation is provided in HTML and Adobe Acrobat formats.
Viewing online documentation All ColdFusion documentation is available online in HTML and Adobe Acrobat Portable Document Format (PDF) files. To view the HTML documentation, open the following URL on the web server running ColdFusion: http://web_root/cfdocs/dochome.htm. ColdFusion documentation in Acrobat format is available on the ColdFusion product CD-ROM.
PART I Welcome to ColdFusion Part I provides an introduction to ColdFusion. It defines ColdFusion and provides an overview of the ColdFusion Markup Language (CFML) . It also provides generic database concepts, and information about how to prepare your development environment for using the tutorial in Part II of this book. Introducing ColdFusion MX ........................................................................................3 CFML Basics.............................................................
CHAPTER 1 Introducing ColdFusion MX This chapter introduces the core technologies that are the foundation for Macromedia ColdFusion MX. It provides a basic understanding of the Internet, web servers, URLs, HTML, and JavaScript. In addition, it introduces the basic concepts about ColdFusion MX, how it works, and the various components that comprise it. Contents • The Internet and related technologies ...................................................................... 4 • What is ColdFusion MX? ..........
The Internet and related technologies ColdFusion MX is tightly integrated with the Internet and the World Wide Web. For a better understanding of ColdFusion MX, the following sections provide a basic description about the Internet and its related technologies. The Internet One way to think of the Internet is to picture it as a wide-area network that spans multiple geographic locations.
Intranet applications An intranet is a private LAN (Local Area Network) or WAN (Wide Area Network) that lets you use and interact with your Internet-based applications in a secure environment. These private networks exist in large corporations, small companies, and even home offices. Private networks let companies and organizations determine who can share their information and who can access it. An intranet application is an application that works on a private intranet (network).
Web browsers A web browser is a software program residing on a computer that you use to view pages on and navigate the World Wide Web. When you use a browser to request a page on a website, that browser is making a web connection to a web server. As mentioned previously, the web browser processes the web pages that it receives from a web server and displays the pages to the user.
URLs Every piece of information on the World Wide Web has a unique address. This address is called a Uniform Resource Locator, or URL. A URL is a pointer to some bit of data on the web. This information might include a web document, a file on a FTP site, a posting on Usenet, or even an e-mail address. URLs contain information about the following: • How to get the information (what protocol to use: FTP, HTTP, and so on) • The Internet host name to contact (for example, www.macromedia.
Web application servers process code in a page that a browser and web server cannot interpret. The web server recognizes these requested pages by the file extension and forwards it to the web application server for action. The web application server interprets the programming instructions in the page and generates output that a web browser can interpret. Then the web server returns the output to the browser.
The ColdFusion application server The ColdFusion application server is a software program that resides on the same computer as your web server software. It is the program that parses (reads and interprets) and processes supplied instructions. These instructions are passed to ColdFusion through ColdFusion pages, which use a CFM or CFC file extension. A ColdFusion page looks like an HTML page but contains special tags that instruct the ColdFusion server to perform specific operations.
Development tools While you can code your ColdFusion application with NotePad or any HTML editor, Macromedia recommends that you build your applications using Macromedia Dreamweaver MX. Dreamweaver MX offers features and wizards that enhance ColdFusion development. For more information about Dreamweaver MX, see Chapter 4, “Configuring Your Development Environment” on page 35. The ColdFusion MX Administrator You use the ColdFusion MX Administrator to configure and maintain the ColdFusion application server.
Using ColdFusion MX with Macromedia Flash MX Macromedia Flash MX is designed to overcome the many limitations of HTML and solve the problem of providing efficient, interactive, user interfaces for Internet applications. ColdFusion MX is designed to provide a fast efficient environment for developing and providing data-driven Internet applications. By using ColdFusion MX and Flash MX together, you can easily create complete visually interactive applications for the Internet.
12 Chapter 1 Introducing ColdFusion MX
CHAPTER 2 CFML Basics This chapter introduces the basic elements of CFML, including how to create ColdFusion pages, and use variables, functions, conditional processing, and form processing. Contents • Working with ColdFusion pages............................................................................ 14 • Understanding CFML elements............................................................................. 16 • Working with CFML expressions ..........................................................
Working with ColdFusion pages As discussed in Chapter 1, ColdFusion pages are plain text files that you use to create web applications. You can create your ColdFusion applications by writing all the code manually or by using wizards (provided with some editors) to generate the majority of the code for you.
To create a ColdFusion page: 1 Open your editor and create a blank file. 2 Enter the following code on the page:
A ColdFusion Page Hello world, this is a ColdFusion page.
Today’s date is #DateFormat(Now())# Saving your ColdFusion page In order for the ColdFusion server to process the page, you must save the ColdFusion page on a computer where the ColdFusion server is installed.The following figure shows the cfpage.cfm in the browser: 2 Do the following tasks: a View the source code that was returned to the browser. In most browsers, you can view the source by right-clicking on page then selecting View Source. b Compare the browser source code with the source code that appears in your editor. Notice that the CFML tags were processed on the page but did not appear in the source that was returned to your browser.
Most often the end tag encloses the tag name in brackets and includes a slash (/), like this: The information processed by ColdFusion is placed between the start and end tag, like this: info to be processed ... ColdFusion tags, for the most part, share these common characteristics: • All start with cf. • A start and end tag. • Use of attributes (like html tags), and most attributes have values. Some ColdFusion tags, such as cfset, omit the closing tag.
The DollarFormat function returns a value as a string and formats that value with two decimal places, thousand separator, and dollar sign. The pounds signs (#) around the function instruct ColdFusion to evaluate the content between the pound signs and display the value. Functions and parentheses All functions have parentheses, regardless of whether the function acts on data. Consider the following function: #Now()# If you put anything inside the parentheses of the Now() function, an error would occur.
If you did not include the pound signs around the DateFormat(Now(), "mm/ddyyy") function, the output for the previous example would display as follows: For more information about how to use pound signs with functions, see Developing ColdFusion MX Applications with CFML. Variables Variables let you store data in memory on the server. Variables always have a name and a value.
In the next example, ColdFusion uses the values of the my_first_name and my_last_name variables to set the value for the my_full_name variable in the last line of code. The ampersand (&) string operator joins the variables, and the space surrounded by double quotation marks (" ") adds a space between the variables.
One of the tags that ColdFusion provides to display output is the cfoutput tag. The cfoutput tag instructs ColdFusion to process all the code between the cfoutput start and end tags. The syntax for the cfoutput tag looks like this: {normal html, text, and coldfusion processing instructions} To return the value of a variable, you must always surround the variable name with pound signs (#) and place the variable name between the cfoutput start and end tags.
As mentioned, it is important that elements are identified properly in your expression so ColdFusion processes them as expected, and you can avoid unnecessary errors. When writing expressions, consider the following coding practices: • Character case consistency • When to use the pound (#) sign • When quotation marks are needed Specifying a consistent character case Because the ColdFusion server is case-insensitive, you can write expressions using all uppercase, all lowercase, or mixed case.
Specifying quotation marks around values When assigning literal values to variables, you must surround the literal value with double quotation marks or single quotation marks. ColdFusion interprets the content between the quotation marks as a literal value and assigns that value to the variable; for example: ColdFusion instantiates the variable my_first_name to the string literal Kaleigh.
Nonsupported logical operator Equivalent ColdFusion decision operator Description > GT GREATER THAN Tests for greater than. >= GTE, GREATER THAN OR EQUAL TO Tests for greater than or equal to <> IS NOT, NEQ, NOT EQUAL Tests for nonequality. CONTAINS Tests whether a value is contained within a second value. DOES NOT CONTAIN Tests whether a value is not contained within a second value.
Understanding conditional processing To this point, all the coding examples shown are considered linear coding examples. Linear code is when ColdFusion executes code starting with the first line on the page, and processes every line in order. Although you will use linear code in your applications, you will often write code that performs various actions based on conditions, such as the following: • Determine if a user entered a value in a form field. • Display results based on user input.
Using cfelseif to evaluate multiple expressions To evaluate multiple expressions in a cfif statement, you can use cfelseif and cfelse in your statement, for example: HTML and CFML tags executed if expression 1 is True. HTML and CFML tags executed if expression 2 is True. HTML and CFML tags executed for expression(s) that is False. The following example shows you how you can evaluate multiple expressions using these tags.
When a user submits a form, the form values are stored in form variables and sent to the action page for processing. The following figure shows the relationship between the form page and action page: Form page Name E-mail Submit form.var1=value1 form.var2=value2 The action page contains the code for form processing and interaction with database.
Commenting your code As in other programming languages, it is important to include comments in the code. You should comment your code for the following reasons: • Commented code is easier to debug than code that is not commented. • If you describe the code on the page, it is easier to make modifications. • Commented code tends to be better organized.
CHAPTER 3 Database Fundamentals This chapter provides a quick overview of relational database concepts and terms. It describes what a database is and how it is organized. It also discusses the Structured Query Language (SQL) that you use to interact with databases. Contents • Understanding database basics ............................................................................... 30 • About SQL ............................................................................................................
Understanding database basics Even though you do not need a thorough understanding of database management systems to create ColdFusion applications, you must understand some basic concepts and techniques about databases. The information in this chapter will get you started with ColdFusion. What is a relational database? A relational database is a structured collection of information that is related to a particular subject or purpose, such as an inventory database or a human resources database.
Understanding relational tables In a database, you can organize data in multiple tables. For example, if you manage a database for the Human Resource department, you might have one table that lists all the employees information and another table that lists all the departments.
About SQL SQL Structured Query Language) is a language that lets you communicate with databases. For example, you can use SQL to retrieve data from a database, add data to a database, delete or update records in a database, change columns in multiple rows, add columns to tables, and add and delete tables. Using SQL to interact with a database Unlike other computer languages, SQL is made up of a small number of language elements that let you interact efficiently with a database.
Using SQL with ColdFusion ColdFusion communicates with your data source through a database interface called JDBC. JDBC is a standard application programming interface (API) for accessing information from different database systems and different storage formats. About data sources A data source is a complete database configuration that uses a JDBC driver to communicate with a specific database. In ColdFusion, you must configure a data source for each database file that you want to use.
34 Chapter 3 Database Fundamentals
CHAPTER 4 Configuring Your Development Environment This chapter describes how to set up your development environment for the tutorial in Part II of this book. It specifies the tutorial file structure, and how to configure the database connection and debugging options in the ColdFusion Administrator. Additionally, it provides a brief overview of using Macromedia Dreamweaver MX or Macromedia HomeSite+ for ColdFusion development. Contents • Verifying the tutorial file structure ...............................
Verifying the tutorial file structure Before you being the tutorial, verify that the configuration of the computer where ColdFusion is installed matches the file structure described in the following sections. The files required to complete the Compass Travel tutorial (in Part II of this book) are installed under the web server root directory.
The photos directory contains the required photo files for the tutorial application. The solutions directory provides sample application files that you can use when building the tutorial application. Configuring database connection and debugging options Prior to ColdFusion development, use the ColdFusion MX Administrator to define the connection to the sample database file and any optional debugging options.
4 Specify the following: Field Action Database File text box Specify the location of the CompassTravel.mdb file. Click Browse to locate and select the CompassTravel.mdb file. By default, ColdFusion MX installs the CompassTravel.
3 Click Add to configure the data source name and driver. The PointBase data source dialog box appears: 4 Specify the following: Field Action JDBC URL Enter the following JDBC URL for the Compass Travel pointbase files: jdbc:pointbase:compasstravel,database.
7 Click Verify All Connections to ensure that ColdFusion can access this file. OK appears in the Status column for successful connections. If the connection to the compass travel data source fails, • • do the following: Verify that the name of the data source file does not contain a space. If it does contain a space, delete the data source from the Connected Data Source dialog box.
The location of the debugging information or the type of debugging data shown varies, depending on the options that you enable on the Debugging page in the ColdFusion Administrator. In the following example, the debugging output includes general information about the ColdFusion server, the execution time of the application, and variable information.
For the purpose of the tutorial in Part II of this book, enable the following debugging options: Option Description Database Activity Identifies database activity related to SQL query events. Exception Information Identifies ColdFusion exceptions raised in the debugging output. Tracing Information Lets you trace event information reported in the debugging output. Form, URL and Session Displays variable information in the debugging output. Variables 4 Click Submit Changes when you are done.
Macromedia development environment tools Macromedia Dreamweaver MX is the preferred development environment for building ColdFusion MX applications. It combines the best code editing features of ColdFusion Studio with the visual design features of Dreamweaver. Dreamweaver MX window Dreamweaver MX supports the latest ColdFusion MX features and tags.
The Dreamweaver MX environment As a ColdFusion developer, you can build ColdFusion MX applications by writing the code manually or generating the code by using one of the code-generating tools provided with Dreamweaver MX. Features for ColdFusion developers Dreamweaver MX provides a wide variety of code editing features for ColdFusion developers, including the following: • Rich tag editors for quickly setting attributes and values for every CFML tag. • Code hints for writing CFML tag attributes.
Configuring Dreamweaver MX for ColdFusion development Before you use Dreamweaver MX to create the sample application in Part II of this book, you must configure Dreamweaver to recognize the tutorial files and data sources. To configure Dreamweaver MX to create the sample application: 1 Create a site that contains the tutorial files. For information about how to create a site in Dreamweaver MX, see the Dreamweaver MX online Help or Using Dreamweaver MX.
46 Chapter 4 Configuring Your Development Environment
PART II Building a ColdFusion Application Part II provides a tutorial that steps you through building a sample ColdFusion application. It consists of six lessons: Preparing to Build the Sample Application .........................................................49 Writing Your First ColdFusion Application...........................................................59 Creating a Main Application Page...........................................................................
LESSON 1 Preparing to Build the Sample Application In this tutorial, you will build a simple ColdFusion web application for a fictitious travel company called Compass Travel. Compass Travel markets a wide range of adventure trips to the public through its website. Trip coordinators at Compass Travel are responsible for maintaining the trip information made available to the public.
Application development steps Most software applications perform three major functions: • A user interface to capture data. • Logic to validate the captured data. • A database to store the validated data. The process steps to develop these major functions varies from project to project.
Determining the application functional requirements Before you can build the sample application, you must understand the functional requirements underpinning its design. The design of the sample application centers around the daily tasks performed by Compass Travel’s trip coordinators.
Determining the data requirements Prior to creating the application pages to capture trip information, you must determine what type of data is required about each trip. For the example, in this tutorial, the Compass Travel Trip Coordinator must maintain the following information about each trip: • Trip name • Type of event (surfing, mountain climbing, kayaking, etc.
Designing the database for your application After you identify the information to collect, you must consider where to store the data. Prior to creating the data collection form and instructing ColdFusion where to store the form data, you must have a database ready to accept the data. If you had to create the Compass Travel database, you would create a table named Trips to store the information that you plan to collect about each trip.
Establishing a relationship between the two tables When the user selects an event type from the list obtained from reading the eventtypes table, the correct event type must be saved to the trips table with all the other trip related data. The application could store the eventType (for example, mountain climbing) itself into the eventType column in the Trips table.
Developing the sample application Given the application functional requirements and the database provided, you are ready to use ColdFusion to develop the Trips Maintenance application. The remaining lessons in the tutorial will step you through the process of constructing this application.
Each lesson guides you through a scenario to enhance the Compass Travel Trip Maintenance application. Sections within a lesson present basic programming concepts that you need to understand before completing the section exercise(s). Depending on your programming experience, you can read the entire lesson then proceed to the hands-on exercises, or you can skip some information in the lesson and proceed directly to the exercises.
Requirements To use this tutorial, you must have the following components installed: • ColdFusion Server For information on how to install ColdFusion Server, see Installing ColdFusion MX. • Database Management System A database management system can be installed on the same computer as the ColdFusion Server or on a separate computer. For the purpose of this tutorial, a Microsoft Access database file for MS Windows users and a PointBase database file for UNIX users has been provided.
58 Lesson 1 Preparing to Build the Sample Application
LESSON 2 Writing Your First ColdFusion Application In this lesson, you begin the construction of a ColdFusion web application for the fictitious company, Compass Travel. The exercises in this lesson guide you through the steps of creating queries and forms to search for and display trip offering information from the Compass Travel relational database. This lesson explains how to do the following tasks: • Construct a query to retrieve information from a database.
Creating your first ColdFusion application As you recall from Lesson 3, two of the requirements for the Trip Maintenance application are the ability to generate trip listings and a trip query facility. You will create a search interface that meets both of these requirements in this lesson. The following list identifies the components that you will create in this lesson: • Dynamic Trip List page The purpose of the Trip List page is to present an up-to-date lists of trips on the Compass Travel website.
• Trip Search Results page The purpose of the Trip Search Results page is to display the results of a trip search. The primary users of these components are the Compass Travel coordinators and agents, not the general public. Application development steps You will review or participate in the following application construction steps: Steps Description 1 Create a dynamic web page that displays a list of trips. 2 Design the constraints for the search interface.
Using a web page to list trips To help Compass Travel agents take trip reservations by telephone and in person, the trip coordinator maintains a list of current trip offerings. Years ago, the coordinator would type the list and fax it to the various Compass Travel offices in an effort to keep everyone informed.
Consider a table named Clients to hold information about people with the following rows: LastName FirstName Address City Jones Tom 12 State St Boston Adams Anita 521 Beacon St Boston Green Peter 1 Broadway New York To select the columns named LastName and FirstName, use the following SELECT statement: SELECT LastName, FirstName FROM Clients The results of this SQL statement contains the following data: LastName FirstName Jones Tom Adams Anita Green Peter Using the SQL WHERE clause t
For example, to select the columns named Last Name and First Name for Clients whose City is Boston, use the following SELECT statement: SELECT LastName, FirstName FROM Clients Where City = 'Boston' The results of the preceding SQL statement contains the following data: LastName FirstName Jones Tom Adams Anita You can compose a WHERE clause with one or more conditions; these are called subclauses. You join subclauses using the operators AND and OR.
the Trip List page presented earlier in this lesson. In this example, you use cfquery to return all the trip names found in the tripName column within the Compass Travel Trips table.
Creating a dynamic web page In the following exercises you will build a dynamic Trip Listing web page that is always current. The first exercise guides you through constructing a query to retrieve information from the database. In the second exercise, you will enhance the query to sort the query results and to display other pertinent trip information. For your convenience, the following figure shows the Compass Travel Trips table.
Reviewing the code The following table describes the code used to build the query: Code Explanation ColdFusion query named "TripResult". Submits any SQL statement between the cfquery start and end tags to the data source specified in the datasource attribute. SELECT tripName FROM trips SQL SELECT statement to retrieve all tripName(s) from the trips table. #tripName#
Output code block.
3 Create the Budget Trip List report by doing the following: a Modify the SQL SELECT statement, as follows: SELECT tripName, departureDate, returnDate, price FROM trips WHERE price <= 1500 ORDER BY tripName b Change the heading tag from
Trip List
to Budget Trip List
. 4 View the triplisting.cfm in a browser and verify that all the new requirements were met. The revised TripListing.cfm page looks like this: Note that the dates and prices in the preceding listing are not formatted.Developing a search capability The dynamic listings developed in the previous exercise meet many of Compass Travel’s requirements for locating trips. However, what if the number of trips were in the thousands or tens of thousands? Locating the right trip for a customer might be difficult and certainly time consuming. Moreover, it is very hard, if not impossible, to anticipate all the ways that a user might want to search for trips.
• price • tripID In later exercises, you will reference these columns when you build the SQL SELECT statement for the cfquery in the search action page. Understanding search query operators Now that you decided on the queryable columns (tripLocation, departureDate, and price), you can build a simple form that allows the user to enter values for each of these fields.
Using SQL operators to create a search criteria page A simple design for a search criteria page presents an operator list and data entry field for each of the queryable columns. Following this pattern, a page to collect the Compass Travel Trip search criteria looks like this: Since all the code used to produce the search criteria page is HTML, you are not requested to build this page. You will, however, use this page (tripsearch.cfm) later in this lesson to test the search action page.
| | | | Price | | |
Building the Search Results page Based on the queryable columns identified earlier, the SQL query to display the search results would look like this: SELECT tripName, tripLocation, departureDate, returnDate, price, tripID FROM trips The purpose of the Trip Search form is to supply the data needed to build the WHERE clause to finish this SQL SELECT statement and constrain the query according to the user’s input.
Building a SQL WHERE clause in code is largely an exercise in string concatenation. The & operator combines two strings in ColdFusion. For example, the following code snippet: My name is #FullName#. results in the following text: My name is Dylan Smith.
Reviewing the code The following table describes the code used to build the tripLocation WHERE subclause: Code Explanation The cfset tag initializes the WhereClause variable to hold the WHERE clause to be constructed. The initial value is set to "0=0", so that the WHERE clause has at least one subclause in case the user enters no search criteria.
The Trip Results page displays several entries as follows: c Notice in the Trip Results page that only one trip has a trip location of China. d Click the Back button in your browser to return to the Trip Search page. 3 In the Trip Location drop-down list box of the Trip Search page, select the Is option, enter the value China, then click Search. The Trip Results page displays only one entry for the trip to China in the HTML table.
2 To build the departureDate WHERE subclause, enter the code in the following table immediately following the comment line. For Enter this code Windows users, using the MS Access database file " & Form.
4 Verify that the price and departureDate are now considered in the query, as in step 4 in the previous exercise: a Open the tripsearch.cfm page in the my_app directory in your browser. b In the Departure Date drop-down list box, select Before, enter 1/1/1900 as the date, and select Smaller Than 0 for the price. c Click the Search button. Now, because the departure date is considered in the query, there are no rows returned.
Summary This lesson described how to access a relational database using ColdFusion. You used the SQL SELECT statement and the cfquery and cfoutput tags to display trip lists. You built a search tool that dynamically builds a WHERE clause of the SQL SELECT statement using cfif and cfset tags. To ensure that the SQL statement remains intact, you used the PreserveSingleQuotes CFML function. In the next lesson In the next lesson, you will build the main navigation page for the Trip Maintenance application.
LESSON 3 Creating a Main Application Page In this lesson you will enhance the Compass Travel Trip Maintenance application.
Enhancing the Trip Maintenance application In this lesson you will enhance the Trip Maintenance application that you created in Lesson 2. You will modify the application to include a main application page that lets Compass Travel employees do these tasks: • View additional details about a trip. • Scan records in the Trips database table. • Modify or search for records in the Trips database table.
• Enhanced Trip Search Results page. The original purpose of the Trip Search Results page in Lesson 2 was to display the results of a trip search. In this lesson, you will enhance this page to provide a useful drill-down mechanism for accessing additional information about trips that meet the search criteria. • Main Application page In the beginning of this lesson, you will develop the Trip Detail page (see the following figure).
The primary users of these components will be the Compass Travel coordinators and agents, not the general public. Showing additional trip details By design, the Trip Search Results page displays a subset of the information about a trip. To get additional information about any of the trips displayed, the user should be able to click on any row to display the detailed trip data.
Exercise: building a Trip Detail page Follow these steps to build a Trip Detail page. To build a Trip Detail page: 1 Open your editor and create a new ColdFusion page. Remove any lines if your editor adds.
| #returnDate# | | Price: | #price# |
| Base Cost: | #baseCost# |
| Trip Leader: | #tripLeader# |
| Number People: | #numberPeople# |
| Deposit Required: | #depositRequired# |
| Photo File: | #photo# |
5 To provide a title that appears on the browser window, ins8 The Rio Cahabon Rafting trip has an tripID of 24. To view the trip detail for the trip in your browser enter one of the following URLs:: Web server configuration URL For stand-alone ColdFusion web server configuration http://localhost:8500/cfdocs/getting_started/my_app/ tripdetail.cfm For local third-party web server configuration http://localhost/cfdocs/getting_started/my_app/ tripdetail.
Reviewing the code The following table describes the ColdFusion code used to build the Trip Detail page: Code Explanation The cfquery tag includes a maxRows attribute. This attribute limits the number of result rows brought back from the database. In the Trip Detail page, we want to only show a single row at a time, therefore, maxRows is set to 1. WHERE tripID = #URL.ID# The URL.
Protecting your application To ensure that your application is protected from such an attack, you can exploit the fact that the ID must be a numeric value. The CFML Val function returns the numeric value at the beginning of a string expression. You can use the Val function as follows: WHERE tripID = #Val(URL.ID)# Now if non-numeric data is passed within the URL ID field, the Val statement returns 0, and the trip with ID 0 displays (if one exists).
3 In the Trip Location drop-down list box, select Begins With and type the value C in the trip location text box then click Search. The Trip Search Results page displays a hyperlink for each trip name listed, as the following figure shows: 4 To view the Trip Detail page for a trip, click on the trip name. You might notice that the dates and prices in both the Trip Detail and Trip Search Results pages are unformatted. You will improve the appearance of the application in the next exercise.
The following example uses the MOD function to alternate the background color of table rows: Notice that the MOD function uses a variable called CurrentRow. Notice also that CurrentRow is not defined anywhere in tripsearchresult.cfm.Existing code Change to #price# #dollarformat(price)# #baseCost# #dollarformat(baseCost)# 2 To format the currency and date fields on the Trips Search Results page, open the tripsearchresult.cfm in your editor and make the same changes for departureDate, returnDate, and price as in step 1.
5 In the Trip Search Result page, click the link for Riding the Rockies. The properly formatted Trip Detail page appears: Creating the main application page from the Trip Detail page To this point in the tutorial, you created a very useful drill-down query facility. Compass Travel trip coordinators can produce lists required by management and easily locate and display information about any trip.
Adding navigation buttons to browse database The drill-down search function developed in the last exercise is very useful when the user knows some search criteria to enter. Unfortunately, however, flipping back and forth between the results page and the detail page to navigate through a record set can be tedious. Moreover, on occasion the trip coordinator might want to browse the Trips database just to check for anomalies or to become familiar with its contents.
3 Save the file and view the updated tripdetail.cfm page in a browser. The Trip Search Results page appears: 4 Test the buttons by clicking any navigation button. An error occurs because the navigation action page (navigationaction.cfm) does not exist. The navigation action page processes the navigation button requests. You will build the navigation action page in the next lesson.
Adding database maintenance buttons The search and sequential navigation capabilities are features for locating Compass Travel trips. After the trip coordinator locates a trip, they must be able to modify or delete the trip. Additionally, when viewing the detail for a trip, they must be allowed to add a new trip or use the search facility.
3 Save the file and view the updated tripdetail.cfm page in a browser (http:// localhost/CFDOCS/getting_started/my_app/tripdetail.cfm). The page appears as follows: 4 Click Search or Delete to test the database maintenance buttons. An error occurs because the Maintenance Action page does not exist. The Maintenance Action page is required to process the maintenance button requests. You will develop this page in the next lesson.
Summary In this lesson, you transformed the search facility you built in Lesson 2 into a drill-down facility for trip queries. You built a Trip Detail page to show more information about a particular trip. You also formatted the Trip Search Results and Trip Detail pages using the CFML DollarFormat and DateFormat functions. You linked the Trip Search Results page with the Trip Detail page. You used the URLEncodedFormat CFML function to ensure that data was correctly from one page to the other.
LESSON 4 Validating Data to Enforce Business Rules In this lesson, you will enhance the Compass Travel Trip Maintenance application. The exercises in this lesson will guide you through the steps of enhancing the application to provide a page for the trip coordinator to add new trip offerings and update existing trips. Further, you will add logic to validate that data entered against Compass Travel business rules.
Enhancing the Trip Maintenance application In this lesson and the next, you will create the code to implement the remaining maintenance buttons on the main Trip Maintenance application page. The remaining buttons are Add and Edit. You will develop the data entry form to capture new trip information and validate the data entered against Compass Travel business rules. You will then modify the data entry form to edit existing trips.
Using an HTML form to collect data Based on the data requirements determined in Lesson 1, the following figure shows the Trip Edit data collection page: Exercise: view the source and test the Trip Edit page To view the source and test the Trip Edit data collection form: 1 Open an editor, then locate and open the file tripedit1.cfm in the solutions directory \cfdocs\getting_started\solutions under your web root directory. 2 Review the HTML source code used to create the Trip Edit page.
Tag Description Table You can format a data entry form and display its controls neatly, by using the table tag, table, table row tag, tr, and the table data tag, td. Form Controls The form requires controls to collect and submit user input. There are a variety of types of form controls you can use. For this lesson, you will use the following controls: • . Accepts text answers such as Trip Name and Trip Price. • .
Developing code to validate data and enforce business rules As described in Lesson 1, it is important to define the right data type for each column on the tables in the database. A fundamental concern, therefore, is ensuring that the captured data is suitable for the column definitions in the Trips table. This type of validation on a single field is often referred to as a single-field edit. Compass Travel has other operating policies that involve evaluating the values from more than one field.
Validating data using a server-side action page The first approach you will take to enforce Compass Travel business rules is to develop an action page to validate the data collected on the data entry form. The action page receives a form variable for every field on the form that contains a value. You use the cfif tag to test the values of these fields to ensure that they adhere to Compass Travel business policy.
The cfset tag lets you manipulate the value of a variable. For example, the following pseudocode initializes a variable to a specific value and checks the value using the cfif statement: if rule 1 fails then ... update the database In the previous example, cfset initializes the local variable isOk to Yes. If any rule fails, the variable isOK is set to No.
Price must be marked up at least 20% above cost.
Note: The code for business rule 7 uses ColdFusion cfif and cfelse conditional processing tags. The code inside the cfif tags only executes when the condition evaluates to True. To perform other actions when the condition evaluates to False, the cfelse tag is used.
the network and the server. If the data is validated on the client, then only valid data is posted to the server and traffic is reduced. Validating data on the client using ColdFusion form tags An alternative approach to server-side editing is to use client-side scripting. Client-side scripting lets you validate the form data entered on the client prior to posting it to the server. CFML provides alternative versions of standard HTML form tags that provide advantages of client-side data validation.
Client-side validation approach using ColdFusion form tag The following code is on the client: Code Explanation Use the cfinput tag to create the duration input entry field within a cfform.
Tip: For additional help, review the completed code in the tripedit2.cfm within the solutions directory. For more details about using ColdFusion form tags and their attributes, see Developing ColdFusion MX Applications with CFML. 5 In your editor, open the tripeditaction.cfm in the my_app directory and delete the code for the following single-field validation rule: • Trip name is required. • Trip leader is required. • Photo file name is required. • Number of people is required and must be numeric.
