Adobe COLDFUSION 9 Manual page 156

DEVELOPING COLDFUSION 9 APPLICATIONS
Building Blocks of ColdFusion Applications
</cf_myTag>
For information on using the
Custom CFML Tags" on page 208.
Recommended uses
ColdFusion custom tags let you abstract complex code and programming logic into simple units. These tags let you
maintain a CFML-like design scheme for your code. You can easily distribute your custom tags and share tags with
others. For example, the ColdFusion Developer Exchange includes a library of custom tags that perform a wide variety
of often-complex jobs; see www.adobe.com/go/learn_cfu_exchange_en.
Consider using CFML custom tags in the following circumstances:
• You need a tag-like structure, which has a body and an end tag, with the body contents changing from invocation
to invocation.
• You want to associate specific processing with the beginning tag, the ending tag, or both tags.
• To use a logical structure in which the tag body uses "child" tags or subtags. This structure is like the
which uses subtags for the individual form fields.
• You do not need a function format in which the calling code uses a direct return value.
• Your code must be recursive.
• Your functionality is complex.
• To distribute your code in a convenient form to others.
If you can create either a UDF or a custom CFML tag for a purpose, first consider creating a UDF because running it
requires less system overhead than using a custom tag.
For more information
For more information on custom CFML tags, see
Using CFX tags
ColdFusion Extension (CFX) tags are custom tags that you write in Java or C++. Generally, you create a CFX tag to do
something that is not possible in CFML. CFX tags also let you use existing Java or C++ code in your ColdFusion
application. Unlike CFML custom tags, CFX tags cannot have bodies or ending tags.
CFX tags can return information to the calling page in a page variable or by writing text to the calling page.
CFX tags can do the following:
• Have any number of custom attributes.
• Create and manipulate ColdFusion queries.
• Dynamically generate HTML that your page returns to the client.
• Set variables within the ColdFusion page from which they are called.
• Throw exceptions that result in standard ColdFusion error messages.
Calling CFX tags
To use a CFX tag, precede the class name with cfx_ and place the name in angle brackets. For example, use the
following line to call the CFX tag defined by the MyCFXClass class and pass it one attribute.
<cfx_MyCFXClass myArgument="arg1">
and tags to call custom CFML tags, see
cfmodule cfimport
"Creating and Using Custom CFML
Last updated 8/5/2010
"Creating and Using
tag,
cfform
Tags" on page 208.
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