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DEVELOPING
COLDFUSION 9 APPLICATIONS
Building Blocks of ColdFusion Applications
Las
t
upda
te
d 8/5/2010
Passing parameters by using attribute format
You can pass parameters in the
cfinvoke
tag as tag attribute name-value pairs, as the following example shows:
<cfinvoke component="authQuery" method="getAuthSecure"
lastName="#session.username#" pwd="#url.password#">
In the example, the parameters are passed as the
lastName
and
pwd
attributes.
Note:
The
cfinvoke
tag attribute names are reserved and cannot be used for parameter names. The reserved attribute
names are:
component
,
method
,
argumentCollection
, and
returnVariable
. For more information, see the CFML
Reference.
Passing parameters in the argumentCollection attribute
If you save attributes to a structure, you can pass the structure directly using the
cfinvoke
tag’s
argumentCollection
attribute. This technique is useful if an existing structure or scope (such as the Forms scope) contains values that you
want to pass to a CFC as parameters, and for using conditional or looping code to create parameters.
When you pass an argumentCollection structure, each structure key is the name of a parameter inside the structure.
The following example passes the Form scope to the
addUser
method of the UserDataCFC component. In the method,
each form field name is a parameter name; the method can use the contents of the form fields to add a user to a
database.
<cfinvoke component="UserDataCFC" method="addUser" argumentCollection="#Form#">
Passing parameters by using the cfinvokeargument tag
To pass parameters in the
cfinvoke
tag body, use the
cfinvokeargument
tag. Using the
cfinvokeargument
tag, for
example, you can build conditional processing that passes a different parameter based on user input.
The following example invokes the
corpQuery
component:
<cfinvoke component="corpQuery" method="getEmp">
<cfinvokeargument name="lastName" value="Wilder">
</cfinvoke>
The
cfinvokeargument
tag passes the
lastName
parameter to the component method.
In the following example, a form already let the user select the report to generate. After instantiating the
getdata
and
reports
components, the action page invokes the
doquery
component instance, which returns the query results in
queryall
. The action page then invokes the
doreport
component instance and uses the
cfinvokeargument
tag to
pass the query results to the
doreport
instance, where the output is generated.
<cfobject component="getdata" name="doquery">
<cfobject component="reports" name="doreport">
<cfinvoke component="#doquery#" method="#form.whichreport#" returnvariable="queryall">
<cfinvoke component="#doreport#"method="#form.whichreport#">
<cfinvokeargument name="queryall" value="#queryall#">
</cfinvoke>
Passing parameters in direct method invocations
ColdFusion provides three methods for passing parameters to CFC methods in direct method invocations:
1
You can pass the parameters the form of comma-separated
name="value"
entries, as in the following CFScript
example:
authorized = securityCFC.getAuth(name="Almonzo", Password="LauRa123");