User Guide

Using Custom Tags 173

6 Include the header.cfm file in this page:

7 View askemp.cfm in a browser, then submit the form so that you display

getemp.cfm.

The header should appear on both pages.

Note

The file header.cfm must be in the same directory where you saved askemp.cfm and

getemp.cfm (or a subdirectory). If it is not, make sure it is in a directory that has a

mapping defined in ColdFusion Administrator, or move it to the appropriate

directory.

Using Custom Tags

Custom tags wrap functionality in a page that can be called from a ColdFusion

application page. ColdFusion custom tags built in CFML allow for rapid application

development and code reuse while offering off-the-shelf solutions to many

programming chores.

You use a custom tag just as you would use a standard HTML or ColdFusion tag, for

example, you might call a custom tag to generate a happy birthday message as

follows:

<CF_HappyBirthday name="Ted Cantor" birthDate="December, 5, 1987">

A custom tag can also have a body and end tag, for example:

<CF_HappyBirthdayMessge name="Ellen Janes" birthDate="June, 8, 1993">

<P> Happy Birthday Ellen!</P>

</CF_HappyBirthdayMessage>

You call custom tags by adding the cf_ prefix to the filename (without the .cfm

suffix). For example, use the tag name

cf_getweather to call the file getweather.cfm.

You must store custom tags that you call directly in either the same directory as the

calling page, in the CFUSION\CustomTags directory, or in a subdirectory of the

CFUSION\CustomTags directory. Each file defines a single custom tag.

You can also use the

cfmodule tag to call custom tags. The cfmodule tag lets you

specify the location of the custom tag file. The

cfmodule tag is useful if you are

concerned about possible name conflicts when invoking a custom tag or if the

application must use a variable to dynamically call a custom tag at runtime. For

more information on using the

cfmodule tag, see theCFML Reference.