CFML Reference
ColdFusion Tags

cfinvoke

Description

Invokes component methods from within a ColdFusion page or component. You use this tag to reference a WSDL file and consume a web service from within a block of CFML code.

This tag works as follows:

• Instantiates a component or web service and invokes a method on it
• Invokes a method on an instantiated component or web service

This tag can pass parameters to a method in the following ways:

• With the cfinvokeargument tag
• As named attribute-value pairs, one attribute per parameter
• As a structure, in the argumentCollection attribute

Category

Extensibility tags

Syntax  

<!--- Syntax 1 - this syntax invokes a method of a component --->
<cfinvoke
  component = "component name or reference"
  method = "method name"
  returnVariable = "variable name"
  argumentCollection = "argument collection"
  ...>
OR
<!--- Syntax 2 - this syntax can invoke a method of a component only
  from within the component. --->
<cfinvoke
  method = "method name"
  returnVariable = "variable name"
  argumentCollection = "argument collection"
  ...
>
OR
<!--- Syntax 3 - this syntax invokes a web service --->
<cfinvoke 
  webservice = "URLtoWSDL_location" 
  method = "operation_name"
  username = user name"
  password = "password"
  inputParam1 = "value1"
  inputParam2 = "value2"
  ...
  returnVariable = "var_name"   
  ...>
OR
<!--- Syntax 4A - this syntax invokes a component.
This syntax shows instantiation with the cfobject tag. 
This cfinvoke syntax applies to instantiating a component 
with the cfobject tag and to instantiating a component 
with the createobject function. --->
<cfobject
  component = "component name"
  name = "mystringname for instantiated object">
<cfinvoke 
  <!--- value is object name, within pound signs --->
  component = "#mystringname for instantiated component#">
OR
<!--- Syntax 4B - this syntax invokes a web service.
This syntax shows instantiation with the cfobject tag. 
This cfinvoke syntax applies to instantiating a web service
with the cfobject tag and to instantiating a web service
with the createobject function. --->
<cfobject
  webservice = "web service name"
  name = "mystringname for instantiated object"
  method = "operation_name">
<cfinvoke 
  <!--- value is object name, within pound signs --->
  webservice = "#my stringname for instantiated web service#" > 

See also

cfargument, cfcomponent, cffunction, cfinvokeargument, cfobject, cfproperty, cfreturn

History

New in ColdFusion MX: This tag is new.

Attributes

Attribute	Req/Opt	Default	Description
component	See Usage section		String or component object; a reference to a component, or component to instantiate.
method	See Usage section		Name of a method. For a web service, the name of an operation.
returnVariable	Optional		Name of a variable for the invocation result.
argumentCollection	Optional		Name of a structure; associative array of arguments to pass to the method.
username	Optional		Overrides username specified in Administrator > Web Services.
password	Optional		Overrides password specified in Administrator > Web Services.
webservice	Required		The URL of the WSDL file for the web service.
input_params ...			Input parameters.

Usage

The following table shows which attributes of this tag are required:

Specifying this attribute is required, optional or unnecessary (blank):	For this cfinvoke tag syntax:
	Syntax 1	Syntax 2	Syntax 3	Syntax 4A	Syntax 4B
component	Required	Optional		Required
method	Required	Required	Required		Required
returnVariable	Optional	Optional	Optional		Optional
argumentCollection	Optional	Optional	Optional		Optional
username			Optional		Optional
password			Optional		Optional
webservice			Required		Required
input_params ...	Optional	Optional	Optional		Optional

If the component attribute specifies a component name, the component with the corresponding name is instantiated, the requested method is invoked, and then the component instance is immediately destroyed. If the attribute contains a reference to an instantiated component object, no instantiation or destruction of the component occurs.

Method arguments can be passed in one of the following ways (and, if an argument is passed in more than one way with the same name, this order of precedence applies):

1. Using the cfinvokeargument tag
2. Passing directly as attributes of the cfinvoke tag (they cannot have the same name as a registered cfinvoke attribute: method, component, webservice, returnVariable)
3. Passing as struct keys, using the argumentCollection attribute

For example, the params struct contains three keys: a=1, b=1, c=1. The following call is evaluated as if the arguments were passed to the method in the order a=3, b=2, c=1:

<cfinvoke ... a=2 b=2 argumentCollection=params>

    <cfinvokeargument name="a" value="3">
  </cfinvoke>

Note:   The following cfinvoke tag attribute names are reserved; they cannot be used for parameter names: component, method, argumentCollection, and result.

Example 1

This example uses Syntax 1.

<!--- immediate instantiation and destruction --->
<cfinvoke 
  component="nasdaq.quote" 
  method="getLastTradePrice" 
  returnVariable="res">
  <cfinvokeargument 
    name="symbol" 
    value="macr">
</cfinvoke>
<cfoutput>#res#</cfoutput>

Example 2

This example uses Syntax 1.

<!--- passing the arguments using argumentCollection --->

<cfset args = StructNew()>
<cfset args.symbol = "macr">
<cfinvoke 
  component="nasdaq.quote" 
  method="getLastTradePrice" 
  argumentCollection="#args#" 
  returnVariable="res">
<cfoutput>#res#</cfoutput>

Example 3

This example uses Syntax 2.

<!--- called only from within a component, MyComponent--->

<cfinvoke
  method = "a method name of MyComponent"
  returnVariable = "variable name">

Example 4

This example uses Syntax 3.

<!--- using cfinvoke to consume a web service using a ColdFusion component --->

<!--- put the following code in a ColdFusion page named wscfml.cfm:--->
<cfinvoke 
  webservice='http://www.xmethods.net/sd/2001/BabelFishService.wsdl'
  method='BabelFish'
  translationmode="en_es" 
  sourcedata="Hello world, friend"
  returnVariable='foo'>
<cfoutput>#foo#</cfoutput>

For more information on the BabelFish web service example, see Developing ColdFusion MX Applications with CFML.

Example 5

This example uses Syntax 4A.

<!--- separate instantiation and method invocation; useful for 

  multiple invocations using different methods or values--->
<cfobject 
  name="quoteService" 
  component="nasdaq.quote">
<cfinvoke 
  component="#quoteService#" 
  method="getLastTradePrice" 
  symbol="macr" 
  returnVariable="res_macr">
<cfoutput>#res#</cfoutput>
<cfinvoke 
  component="#quoteService#" 
  method="getLastTradePrice" 
  symbol="mot" 
  returnVariable="res_mot">
<cfoutput>#res#</cfoutput>

Copyright © 2002, Macromedia Inc. All rights reserved.

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