MACROMEDIA ColdFusion MX, Develop Manual

Page: 225 / 860

Using ColdFusion components 225
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If you invoke a CFC method remotely, using a specific URL, form field, Flash Remoting MX,
or a web service invocation, ColdFusion looks in the specified path relative to the web root.
For form fields and URLs specified directly on local web pages, ColdFusion also searches
relative to the page directory.
Note: On UNIX and Linux systems, ColdFusion MX attempts to match a CFC name or Custom tag
name with a filename as follows: First, it attempts to find a file with the name that is all lowercase. If it
fails, it then tries to find a file whose case matches the CFML case. For example, if you specify
<cfobject name="myObject" Component="myComponent">
, ColdFusion first looks for
mycomponent.cfc and, if it doesn't find it, ColdFusion looks for myComponent.cfc.
Instantiating CFCs
If you use a CFC multiple times in a ColdFusion request, or if you use a CFC with persistent
properties, use the
cfobject
tag or
CreateObject
function to instantiate the CFC before you
call its methods.
The following example uses the
cfobject
tag to create an instance of the tellTime CFC.
<cfobject component="tellTime" name="tellTimeComp">
The following example uses the
cfobject
tag to instantiate the same component in CFScript:
tellTimeComp = CreateObject("component", "tellTime");
CFC invocation techniques
There are many ways to invoke or call CFC methods. The following table lists the techniques,
including the ColdFusion tags and functions that you use:
Invocation Description For more information
cfinvoke tag Invokes a component method. Can invoke
methods of a CFC instance or invoke the
methods transiently. See “Invoking CFC methods with
the cfinvoke tag” on page 226 .
cfset
tag and
assignment
statements
Invoke methods and access properties of a
component instance. See “Using components directly in
CFScript and CFML” on page 229 .
URL
(HTTP GET) Transiently invokes a component method by
specifying the component and method
names in the URL string. See “Invoking component methods
using a URL” on page 230 .
Form control
(HTTP POST) Transiently invokes a component method
using the HTML
form
and
input
tags and
their attributes.
See “Invoking component methods
using a form” on page 231 .
Flash Remoting NetServices ActionScript functions can
transiently invoke component methods. See Chapter 29, “Using the Flash
Remoting Service,” on page 641 .
Web services The cfinvoke tag and CFScript consume
web services in ColdFusion MX. External
applications can also consume CFC
methods as web services.
See Chapter 32, “Using Web
Services,” on page 707 .