Using UDFs effectively
213
For example, the following variation on a “Hello world” function displays an error message if you
do not enter a name in the form:
<cfform method="POST" action="#CGI.script_name#">
<p>Enter your Name:
<input name="name" type="text" hspace="30" maxlength="30">
<input type="Submit" name="submit" value="OK">
</cfform>
<cfscript>
function HelloFriend(Name) {
if (Name is "") WriteOutput("You forgot your name!");
else WriteOutput("Hello " & name &"!");
return "";
}
if (IsDefined("Form.submit")) HelloFriend(Form.name);
</cfscript>
Reviewing the code
The following table describes the code:
Code
Description
<cfform method="POST"
action="#CGI.script_name#">
<p>Enter your Name:
<input name="name" type="text"
hspace="30"
maxlength="30">
<input type="Submit" name="submit"
value="OK">
</cfform>
Creates a simple form requesting you to enter your
name.
Uses the script_name CGI variable to post to this
page without specifying a URL.
If you do not enter a name, the form posts an
empty string as the name field.
<cfscript>
function HelloFriend(Name) {
if (Name is "") WriteOutput("You
forgot your
name!");
else WriteOutput("Hello " & name
&"!");
return "";
}
if (IsDefined("Form.submit"))
HelloFriend(Form.name);
</cfscript>
Defines a function to display "Hello
name
!" First,
checks whether the argument is an empty string. If
so, displays an error message.
Otherwise displays the hello message.
Returns the empty string. (The caller does not use
the return value). It is not necessary to use curly
braces around the if or else statement bodies
because they are single statements.
If this page has been called by submitting the form,
calls the HelloFriend function. Otherwise, the page
just displays the form.
Содержание ColdFusion MX
Страница 1: ...Developing ColdFusion MX Applications...
Страница 22: ...22 Contents...
Страница 38: ......
Страница 52: ...52 Chapter 2 Elements of CFML...
Страница 162: ......
Страница 218: ...218 Chapter 10 Writing and Calling User Defined Functions...
Страница 250: ...250 Chapter 11 Building and Using ColdFusion Components...
Страница 264: ...264 Chapter 12 Building Custom CFXAPI Tags...
Страница 266: ......
Страница 314: ...314 Chapter 14 Handling Errors...
Страница 344: ...344 Chapter 15 Using Persistent Data and Locking...
Страница 349: ...About user security 349...
Страница 357: ...Security scenarios 357...
Страница 370: ...370 Chapter 16 Securing Applications...
Страница 388: ...388 Chapter 17 Developing Globalized Applications...
Страница 408: ...408 Chapter 18 Debugging and Troubleshooting Applications...
Страница 410: ......
Страница 426: ...426 Chapter 19 Introduction to Databases and SQL...
Страница 476: ...476 Chapter 22 Using Query of Queries...
Страница 534: ...534 Chapter 24 Building a Search Interface...
Страница 556: ...556 Chapter 25 Using Verity Search Expressions...
Страница 558: ......
Страница 582: ...582 Chapter 26 Retrieving and Formatting Data...
Страница 668: ......
Страница 734: ...734 Chapter 32 Using Web Services...
Страница 760: ...760 Chapter 33 Integrating J2EE and Java Elements in CFML Applications...
Страница 786: ...786 Chapter 34 Integrating COM and CORBA Objects in CFML Applications...
Страница 788: ......
Страница 806: ...806 Chapter 35 Sending and Receiving E Mail...