GetMetaData

Description

Gets metadata (such as the methods, properties, and parameters of a component) associated with an object that is deployed on the ColdFusion server.

Returns

Structured metadata information: for ColdFusion components (CFCs) and user-defined functions (UDFs), a structure; for query objects, an array of structures.

Category

Function syntax

GetMetaData(object)

See also

History

ColdFusion (2018 release) Update 5: 

  • Array.getmetadata() returns a struct that includes a new key, dimensions
  • The key, datatype, produces a fully qualified path of the component if the data type of the array is a component.

ColdFusion MX 7: Added support for getting query object metadata.
ColdFusion MX: Added this function.

Parameters

Parameter

Description

object

A ColdFusion component, user-defined function, or query object. Within a CFC, the parameter can also specify the This scope.

Usage

This function provides information about application data, and lets applications dynamically determine the structure of an object and how to use it. This function is useful for CFCs and query objects. The metadata for a CFC includes information on the component and its functions, arguments, and properties. The getMetaData function also returns metadata for user-defined functions that are not part of CFCs. Use the GetComponentMetaData function to get information about ColdFusion interfaces, or about CFC definitions that you have not instantiated.The following table lists the data returned by the function for supported object types:

Object Field Description
Component displayname Value of the  cfcomponent  tag  displayname  attribute, if any.
  extends Metadata for the component’s ancestor component. Components that do not explicitly extend another component extend the WEB-INF.cftags.component.
  fullname
The dot-delimited path from the cf_webroot of the component.
  functions
Array of metadata structures for the component’s functions.
  hint
Value of the  cfcomponent  tag  displayname  attribute, if any.
  implements
A structure containing the metadata of the interfaces that the component implements. The key of the structure is the interface name, and the value is a structure containing the interface metadata.
  name
Component name, including the period-delimited path from a component search root such as the web root or a directory specified in the administrator Custom Tag Paths page.
  output
Value of the  cfcomponent  tag output attribute, if any
  path Absolute path to the component.
  properties
Array of structures containing metadata specified by the component’s  cfproperty  tags, if any.
  type
Always, component.
  userMetadata
User-specified attributes in the  cfcomponent  tag
function access Value of the  cffunction  tag access attribute, if any.
  displayname
Value of the  cffunction  tag  displayname  attribute, if any.
  hint
Value of the  cffunction  tag hint attribute, if any.
  name
Function name.
  output
Value of the  cffunction  tag output attribute, if any.
  parameters Array of structures containing metadata for the function parameters.
  returnformat The format in which to return values to a remote caller. This attribute has no effect on values returned to a local caller.
  returntype
Value of the  cffunction  tag  returntype  attribute, if any.
  roles Value of the  cffunction  tag output attribute, if any.
  userMetadata User-specified attributes in the  cffunction  tag.
Parameter or Property default Value of the  cfargument  or  cfproperty  tag default attribute, if any.
  displayname Value of the  cffunction  tag  displayname  attribute, if any.
  hint Value of the  cfargument  or  cfproperty  tag hint attribute, if any.
  name Function parameter or CFC property name.
  required Value of the  cfargument  or  cfproperty  tag required  attribute ,  if any.
  type Value of the  cfargument  or  cfproperty  tag type attribute, if any.
  userMetadata User-specified attributes in the argument tag.
Query IsCaseSensitive Boolean value indicating whether character data must be case correct.
  name
The column name.
 

TypeName

The SQL data type (Omitted if the query object is created with QueryNew without specifying types.)

Note: Use the This scope to access component metadata inside the CFC. The This scope is available at runtime in the component body and in the CFC methods. It is used to read and write variables that are present during the life of the component.

For more information, see Using introspection to get information about components in the Developing ColdFusion Applications.

Example

The following example uses the  cfdump  tag to display metadata for the utilities CFC that is used by the ColdFusion component browser. It also displays the names and data types of the fields in the cfdocexamples database Employees table.

<!--- Create an instance of the Component Explorer utilities CFC. 
and get its metadata ---> 
<cfscript> 
componentutils = createObject("component", "cfide.componentutils.utils"); 
utilmetadata = getMetaData(componentutils); 
</cfscript> 

<h4>Metadata for the CFC component utilities</h4> 
<cfdump var="#utilmetadata#"> 

<!--- use GetMetadata to get the names and data types of the fields in the 
cfdocexamples Employees table ---> 
<cfquery name="getemployees" datasource="cfdocexamples"> 
SELECT * 
FROM Employees 
</cfquery> 
<cfset employeemeta=getMetaData(getemployees)> 

<h4>The Employees table has the following columns</h4> 
<cfloop index="i" from="1" to="#arrayLen(employeemeta)#"> 
<cfoutput> 
#employeemeta[i].name# #employeemeta[i].TypeName# #employeemeta[i].isCaseSensitive#<br> 
</cfoutput> 
</cfloop>