
Using UDFs effectively
209
For example, the following code defines a function to combine a single first name and last name
to make a full name. It queries the CompanyInfo database to get the first and last names of all
employees, then it uses a
cfoutput
tag to loop through the query and call the function on each
row in the query.
<cfscript>
function FullName(aFirstName, aLastName)
{ return aFirstName & " " & aLastName; }
</cfscript>
<cfquery name="GetEmployees" datasource="CompanyInfo">
SELECT FirstName, LastName
FROM Employee
</cfquery>
<cfoutput query="GetEmployees">
#FullName(FirstName, LastName)#<br>
</cfoutput>
You generally use functions that manipulate many rows of a query
outside
tags that loop over
queries. Pass the query to the function and loop over it inside the function. For example, the
following function changes text in a query column to uppercase. It takes a query name as an
argument.
function UCaseColumn(myquery, colName) {
var currentRow = 1;
for (; currentRow lte myquery.RecordCount;
currentRow = curr 1)
{
myquery[colName][currentRow] =
UCase(myquery[colName][currentRow]);
}
Return "";
}
The following code uses a script that calls the
UCaseColumn
function to convert all the last names
in the GetEmployees query to uppercase. It then uses
cfoutput
to loop over the query and
display the contents of the column.
<cfscript>
UCaseColumn(GetEmployees, "LastName");
</cfscript>
<cfoutput query="GetEmployees">
#LastName#<br>
</cfoutput>
Identifying and checking for UDFs
You can use the
IsCustomFunction
function to determine whether a name represents a UDF.
The
IsCustomFunction
function generates an error if its argument does not exist. As a result,
you must ensure that the name exists before calling the function, for example, by calling the
IsDefined
function. The following code shows this use:
<cfscript>
if( IsDefined("MyFunc"))
if( IsCustomFunction( MyFunc ))
WriteOutput("MyFunc is a user-defined function");
else
WriteOutput("Myfunc is defined but is NOT a user-defined function");
else
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...