Writing ColdFusion Plugins

This website contains links to software which is either no longer maintained or will be supported only until the end of 2019 (CKFinder 2). For the latest documentation about current CKSource projects, including software like CKEditor 4/CKEditor 5, CKFinder 3, Cloud Services, Letters, Accessibility Checker, please visit the new documentation website.

If you look for an information about very old versions of CKEditor, FCKeditor and CKFinder check also the CKEditor forum, which was closed in 2015. If not, please head to StackOverflow for support.

Line 63: Line 63:
 
For the sake of simplicity, we'll first create a simple '''plugin.cfm''' that just does exactly what we need:
 
For the sake of simplicity, we'll first create a simple '''plugin.cfm''' that just does exactly what we need:
 
<source>
 
<source>
 +
<!--- (Step 2) Our event handler --->
 
<cffunction name="CKFinderPluginFileSize" returntype="Boolean" output="true">
 
<cffunction name="CKFinderPluginFileSize" returntype="Boolean" output="true">
 
   <cfargument name="command" required="true" type="String">
 
   <cfargument name="command" required="true" type="String">
   <!--- **3** Register the "FileSize" command --->
+
   <!--- Register the "FileSize" command --->
 
   <cfif command eq "FileSize">
 
   <cfif command eq "FileSize">
 
     <cftry>
 
     <cftry>
 +
      <!--- (Step 3) Our custom component that will do the rest --->
 
       <cfset oObject = CreateObject("component", "FileSize")>
 
       <cfset oObject = CreateObject("component", "FileSize")>
 
       <!---
 
       <!---
Line 99: Line 101:
 
   <cfset config.hooks = arrayNew(1)>
 
   <cfset config.hooks = arrayNew(1)>
 
</cfif>
 
</cfif>
<!--- **1** Register the CKFinderPluginFileSize function to be called by the BeforeExecuteCommand hook. --->
+
<!--- (Step 1) Register the CKFinderPluginFileSize function to be called by the BeforeExecuteCommand hook. --->
 
<cfset hook = arrayNew(1)>
 
<cfset hook = arrayNew(1)>
 
<cfset hook[1] = "BeforeExecuteCommand">
 
<cfset hook[1] = "BeforeExecuteCommand">
Line 108: Line 110:
  
 
==== Step1: Register an event handler ====
 
==== Step1: Register an event handler ====
<source lang="php">
+
<source>
$config['Hooks']['BeforeExecuteCommand'][] = array($CommandHandler_FileSize, "onBeforeExecuteCommand");
+
<cfset hook = arrayNew(1)>
 +
<cfset hook[1] = "BeforeExecuteCommand">
 +
<cfset hook[2] = "CKFinderPluginFileSize">
 +
<cfset ArrayAppend(config.hooks, hook)>
 
</source>
 
</source>
  
==== Step2: Create a class ====
+
==== Step2: Create an event handler ====
If your plugin returns an XML response, you'll usually just extend the XmlCommandHandlerBase class to reduce the amount of code to write, however it is not a requirement.
+
Our event handler defined in (1) is called "CKFinderPluginFileSize", so let's define such function.
<source lang="php">
+
<source>
// **2** Include base XML command handler
+
<cffunction name="CKFinderPluginFileSize" returntype="Boolean" output="true">
require_once CKFINDER_CONNECTOR_LIB_DIR . "/CommandHandler/XmlCommandHandlerBase.php";
+
// ...
 +
</source>
  
// Since we will send a XML response, we'll extend the XmlCommandHandlerBase
+
==== Step3: Create a class ====
class CKFinder_Connector_CommandHandler_FileSize extends CKFinder_Connector_CommandHandler_XmlCommandHandlerBase
+
Instead of writing everything in plugin.cfm, we'll create another file, called '''FileSize.cfc''', where we'll add the rest of the code.
</source>
 
  
==== Step3: Create an event handler ====
+
If your plugin returns an XML response, you'll usually just extend the XmlCommandHandlerBase component to reduce the amount of code to write, however it is not a requirement.
Our event handler defined in (1) is called "onBeforeExecuteCommand", so let's define such function.
+
<source>
<source lang="php">
+
<cfcomponent output="false" extends="CKFinder_Connector.CommandHandler.XmlCommandHandlerBase">
function onBeforeExecuteCommand( &$command )
 
// ...
 
 
</source>
 
</source>
  
 
==== Step4: Create the buildXml method ====
 
==== Step4: Create the buildXml method ====
In the <code>onBeforeExecuteCommand</code> method we have called <code>sendResponse</code>. The <code>sendResponse method is defined</code> in XmlCommandHandlerBase class, it creates a basic XML response and calls the <code>buildXml</code> method, which we need to define.
+
In the <code>CKFinderPluginFileSize</code> function we have called <code>sendResponse</code>. The <code>sendResponse method is defined</code> in XmlCommandHandlerBase class, it creates a basic XML response and calls the <code>buildXml</code> method, which we need to define in FileSize.cfc.
<source lang="php">
+
<source>
function buildXml()
+
<cffunction access="public" name="buildXml" hint="send XML response" returntype="boolean" description="send response" output="false">
 
// ...
 
// ...
 
</source>
 
</source>
Line 138: Line 141:
 
==== Step5: Construct the XML response ====
 
==== Step5: Construct the XML response ====
 
The main task of the buildXml method is to construct an XML response, so we're doing it below:  
 
The main task of the buildXml method is to construct an XML response, so we're doing it below:  
<source lang="php">
+
<source>
$oNode = new Ckfinder_Connector_Utils_XmlNode("FileSize");
+
nodeFileSize = XMLElemNew(THIS.xmlObject, "FileSize");
$oNode->addAttribute("size", $size);
+
nodeFileSize.xmlAttributes["size"] = myDir.Size;
$this->_connectorNode->addChild($oNode);
+
ArrayAppend(THIS.xmlObject["Connector"].xmlChildren, nodeFileSize);
 
</source>
 
</source>
  
 
==== Full source code ====
 
==== Full source code ====
The full source code of a plugin with all necessary security checks: (save the code as '''plugin.php''' in "plugins/myplugin" folder)
+
The full source code of a plugin with all necessary security checks:
  
<source lang="php">
+
===== plugin.cfm =====
<?php
+
<source>
 +
<cffunction name="CKFinderPluginFileSize" returntype="Boolean" output="true">
 +
  <cfargument name="command" required="true" type="String">
 +
  <!--- (3) Register the "FileSize" command --->
 +
  <cfif command eq "FileSize">
 +
    <cftry>
 +
      <cfset oObject = CreateObject("component", "FileSize")>
 +
      <!---
 +
      The sendResponse method is defined in XmlCommandHandlerBase, it creates
 +
      a basic XML response and calls the buildXml()method
 +
      --->
 +
      <cfset oObject.sendResponse()>
 +
      <cfcatch type="ckfinder">
 +
        <!--- If an exception occurred, send an error in the XML format --->
 +
        <cfscript>
 +
          oCommandHandler_XmlCommandHandler =
 +
            APPLICATION.CreateCFC("CKFinder_Connector.CommandHandler.XmlCommandHandlerBase").Init();
 +
          oCommandHandler_XmlCommandHandler.sendError(#CFCATCH.ErrorCode#);
 +
        </cfscript>
 +
      </cfcatch>
 +
    </cftry>
 +
    <!--- false = stop further execution --->
 +
    <cfreturn false>
 +
  <cfelse>
 +
    <cfreturn true>
 +
  </cfif>
 +
</cffunction>
  
// A simple protection against calling this file directly.
+
<cfset REQUEST.CKFinderPluginFileSize = CKFinderPluginFileSize>
if (!defined('IN_CKFINDER')) exit;
 
  
// Include base XML command handler
+
<!--- Make sure that both arrays exist --->
require_once CKFINDER_CONNECTOR_LIB_DIR . "/CommandHandler/XmlCommandHandlerBase.php";
+
<cfif not structkeyexists(config, "plugins")>
 +
  <cfset config.plugins = arrayNew(1)>
 +
</cfif>
 +
<cfif not structkeyexists(config, "hooks")>
 +
  <cfset config.hooks = arrayNew(1)>
 +
</cfif>
 +
<!--- (1) Register the CKFinderPluginFileSize function to be called by the BeforeExecuteCommand hook. --->
 +
<cfset hook = arrayNew(1)>
 +
<cfset hook[1] = "BeforeExecuteCommand">
 +
<cfset hook[2] = "CKFinderPluginFileSize">
 +
<cfset ArrayAppend(config.hooks, hook)>
 +
<cfset ArrayAppend(config.plugins, 'myplugin')>
 +
</source>
  
// Since we will send a XML response, we'll reuse the XmlCommandHandler
+
===== FileSize.cfc =====
class CKFinder_Connector_CommandHandler_FileSize extends CKFinder_Connector_CommandHandler_XmlCommandHandlerBase
+
<source>
{
+
<!--- Since we will send a XML response, we'll extend the XmlCommandHandlerBase --->
    // The buildXml method is used to construct an XML response
+
<!--- (2) Extend base XML command handler --->
    function buildXml()
+
<cfcomponent output="false" extends="CKFinder_Connector.CommandHandler.XmlCommandHandlerBase">
    {
 
        // A "must have", checking whether the connector is enabled and the basic parameters (like current folder) are safe.
 
        $this->checkConnector();
 
        $this->checkRequest();
 
  
        // Checking ACL permissions, we're just getting an information about a file, so FILE_VIEW permission seems to be ok.
+
<!--- (4) The buildXml method is used to construct an XML response --->
        if (!$this->_currentFolder->checkAcl(CKFINDER_CONNECTOR_ACL_FILE_VIEW)) {
+
<cffunction access="public" name="buildXml" hint="send XML response" returntype="boolean" description="send response" output="false">
            $this->_errorHandler->throwError(CKFINDER_CONNECTOR_ERROR_UNAUTHORIZED);
+
<cfset var fileName = URL.FileName>
        }
+
<cfset var fileSystem = APPLICATION.CreateCFC("Utils.FileSystem") />
 +
<cfset var coreConfig = APPLICATION.CreateCFC("Core.Config")>
 +
<cfset var currentFolderServerPath = THIS.currentFolder.getServerPath()>
 +
<cfset var filePath = fileSystem.CombinePaths(currentFolderServerPath, fileName)>
  
        // Make sure we actually received a file name
+
<cfif not REQUEST.CheckAuthentication()>
        if (!isset($_GET["fileName"])) {
+
<cfthrow errorCode="#REQUEST.constants.CKFINDER_CONNECTOR_ERROR_CONNECTOR_DISABLED#" type="ckfinder" />
            $this->_errorHandler->throwError(CKFINDER_CONNECTOR_ERROR_INVALID_NAME);
+
</cfif>
        }
 
  
        $fileName = CKFinder_Connector_Utils_FileSystem::convertToFilesystemEncoding($_GET["fileName"]);
+
<cfif not THIS.currentFolder.checkAcl(REQUEST.constants.CKFINDER_CONNECTOR_ACL_FILE_VIEW) >
        $resourceTypeInfo = $this->_currentFolder->getResourceTypeConfig();
+
<cfthrow errorcode="#REQUEST.constants.CKFINDER_CONNECTOR_ERROR_UNAUTHORIZED#" type="ckfinder" />
 +
</cfif>
  
        // Use the resource type configuration object to check whether the extension of a file to check is really allowed.
+
<cfif not fileSystem.checkFileName(fileName) or coreConfig.checkIsHiddenFile(fileName)>
        if (!$resourceTypeInfo->checkExtension($fileName)) {
+
<cfthrow errorcode="#REQUEST.constants.CKFINDER_CONNECTOR_ERROR_INVALID_REQUEST#" type="ckfinder">
            $this->_errorHandler->throwError(CKFINDER_CONNECTOR_ERROR_INVALID_EXTENSION);
+
</cfif>
        }
 
  
        // Make sure that the file name is really ok and has not been sent by a hacker
+
<cfset result = THIS.currentFolder.checkExtension(fileName)>
        if (!CKFinder_Connector_Utils_FileSystem::checkFileName($fileName) || $resourceTypeInfo->checkIsHiddenFile($fileName)) {
+
<cfif not result[1]>
            $this->_errorHandler->throwError(CKFINDER_CONNECTOR_ERROR_INVALID_REQUEST);
+
<cfthrow errorcode="#REQUEST.constants.CKFINDER_CONNECTOR_ERROR_INVALID_REQUEST#" type="ckfinder">
        }
+
</cfif>
  
        $filePath = CKFinder_Connector_Utils_FileSystem::combinePaths($this->_currentFolder->getServerPath(), $fileName);
+
<cfif not fileexists(filePath)>
 +
<cfthrow errorcode="#REQUEST.constants.CKFINDER_CONNECTOR_ERROR_FILE_NOT_FOUND#">
 +
</cfif>
  
        if (!file_exists($filePath) || !is_file($filePath)) {
+
<cfdirectory name="myDir" action="list" directory="#currentFolderServerPath#" filter="#fileName#">
            $this->_errorHandler->throwError(CKFINDER_CONNECTOR_ERROR_FILE_NOT_FOUND);
+
<cfscript>
        }
+
// (5) Adding a <FileSize> element to the XML response.
 +
nodeFileSize = XMLElemNew(THIS.xmlObject, "FileSize");
 +
nodeFileSize.xmlAttributes["size"] = myDir.Size;
 +
ArrayAppend(THIS.xmlObject["Connector"].xmlChildren, nodeFileSize);
 +
</cfscript>
  
        $size = filesize($filePath);
+
<cfreturn true>
 +
</cffunction>
  
        // *** The main part of this plugin ****
+
</cfcomponent>
        // Adding a <FileSize> element to the XML response.
+
</source>
        $oNode = new Ckfinder_Connector_Utils_XmlNode("FileSize");
 
        $oNode->addAttribute("size", $size);
 
        $this->_connectorNode->addChild($oNode);
 
    }
 
 
 
    // Register the "FileSize" command
 
    function onBeforeExecuteCommand( &$command )
 
    {
 
        if ( $command == 'FileSize' )
 
        {
 
            // The sendResponse method is defined in XmlCommandHandlerBase, it creates
 
            // a basic XML response and calls the buildXml()method
 
            $this->sendResponse();
 
            // false = stop further execution.
 
            return false;
 
        }
 
  
        return true ;
 
    }
 
}
 
 
$CommandHandler_FileSize = new CKFinder_Connector_CommandHandler_FileSize();
 
// Register the onBeforeExecuteCommand method to be called by the BeforeExecuteCommand hook.
 
$config['Hooks']['BeforeExecuteCommand'][] = array($CommandHandler_FileSize, "onBeforeExecuteCommand");
 
// (Optional) Register a javascript plugin named "myplugin"
 
$config['Plugins'][] = 'myplugin';
 
</source>
 
 
{{CKFinder_2.x myplugin code}}
 
{{CKFinder_2.x myplugin code}}
 
{{#CUSTOMTITLE:Writing ColdFusion Plugins}}
 
{{#CUSTOMTITLE:Writing ColdFusion Plugins}}

Revision as of 09:56, 25 May 2010

Note: the instruction below is valid only for ColdFusion 8 and later.

CKFinder functionality can be extended with server-side plugins. Although the full source code of the CKFinder server connector is available and can be modified in any way desired, a much better way of enhancing the CKFinder connector is to create a plugin.

The main advantages of plugins are:

  • Upgrades are much easier.
  • The plugin code is stored in a single place.
  • Plugins can be easily disabled when they are not needed anymore.

Common use cases:

  • Adding a new server-side command (i.e. fileditor and imageresize plugin).
  • Working with uploaded files (i.e. watermark plugin).
  • Extending information returned by the Init command (i.e. imageresize plugin).

Creating a plugin

Step1: Create plugin folder

Create a directory for your plugin inside of the "plugins" directory (by default CKFinder comes with three plugins: dummy, fileeditor, imagreresize). Let's use "myplugin" as the plugin name and use the same name for our new folder.

Step2: Create plugin file

Inside of your plugin's folder ("myplugin") create an empty file named plugin.cfm.

Step3: Add plugin definition

// Let's create an empty file for now

Step4: Enable plugin

Include your plugin with include() in the ColdFusion configuration file (config.cfm):

<cfscript>
include( "plugins/myplugin/plugin.cfm" );
</cfscript>

ColdFusion plugin system

Hooks

CKFinder provides several hooks that can be used to extend the functionality of the CKFinder application. Assigning a function (also known as an event handler) to a hook will cause that function to be called at the appropriate point in the main CKFinder code, to perform whatever additional task(s) the developer thinks would be useful at that point. Each hook can have multiple handlers assigned to it, in which case it will call the functions in the order that they are assigned.

Hooks should be assigned in a plugin file. To assign a function to a hook, add an array to config.hooks:

<cfset hook = arrayNew(1)>
<cfset hook[1] = "BeforeExecuteCommand">     <!--- Hook name --->
<cfset hook[2] = "CKFinderPluginSaveFile">   <!--- Function name --->
<cfset ArrayAppend(config.hooks, hook)>

Available hooks

Hook Since Description
AfterFileUpload 2.0 Executed after successful file upload.
BeforeExecuteCommand 2.0 Executed before a server side command is executed.
InitCommand 2.0 Executed straight before sending the result of the Init command.

Enabling JavaScript plugin

Sometimes a server side plugin might come with a client side (JavaScript) plugin, that should be automatically enabled when the server side plugin is enabled.
The config.plugins variable is a special array that does that.

To enable a plugin, simply add it's name to this array.

<cfset ArrayAppend(config.plugins, 'myplugin')>

This code is virtually equal to specyfying in config.js:

config.extraPlugins = 'myplugin';

but the advantage of defining it in plugin.cfm is that it will be enabled only when the server side plugin is also enabled.

Sample plugin: FileSize (adding new server side command - complete example)

Introduction

Probably the best way to learn new things is to write a code, so let's write a plugin that adds a new server side command to the connector. We'll create a command that returns a size of a given file.

If you're unfamiliar with CKFinder architecture, please take a look at Server Side Integration documentation. Alternatively, just bear in mind that CKFinder is an AJAX application and that the connection between the user interface running in a browser and the server connector is simply made of AJAX calls to the connector. Check AJAX calls in Firebug to better understand CKFinder.

The FileSize plugin should provide a new command named "FileSize", in other words, calling:

/ckfinder/core/connector/cfm/connector.cfm?command=FileSize&type=Files&currentFolder=%2F&fileName=foobar.jpg

(assuming that foobar.jpg exists) should return a valid XML response:

<Connector resourceType="Files">
<Error number="0"/>
<CurrentFolder path="/" url="/ckfinder/userfiles/files/" acl="255"/>
<FileSize size="5647"/>
</Connector>

For the sake of simplicity, we'll first create a simple plugin.cfm that just does exactly what we need:

<!--- (Step 2) Our event handler --->
<cffunction name="CKFinderPluginFileSize" returntype="Boolean" output="true">
  <cfargument name="command" required="true" type="String">
  <!--- Register the "FileSize" command --->
  <cfif command eq "FileSize">
    <cftry>
      <!--- (Step 3) Our custom component that will do the rest --->
      <cfset oObject = CreateObject("component", "FileSize")>
      <!---
      The sendResponse method is defined in XmlCommandHandlerBase, it creates 
      a basic XML response and calls the buildXml()method 
      --->
      <cfset oObject.sendResponse()>
      <cfcatch type="ckfinder">
        <!--- If an exception occurred, send an error in the XML format --->
        <cfscript>
          oCommandHandler_XmlCommandHandler = 
                APPLICATION.CreateCFC("CKFinder_Connector.CommandHandler.XmlCommandHandlerBase").Init();
          oCommandHandler_XmlCommandHandler.sendError(#CFCATCH.ErrorCode#);
        </cfscript>
      </cfcatch>
    </cftry>
    <!--- false = stop further execution --->
    <cfreturn false>
  <cfelse>
    <cfreturn true>
  </cfif>
</cffunction>

<cfset REQUEST.CKFinderPluginFileSize = CKFinderPluginFileSize>

<!--- Make sure that both arrays exist --->
<cfif not structkeyexists(config, "plugins")>
  <cfset config.plugins = arrayNew(1)>
</cfif>
<cfif not structkeyexists(config, "hooks")>
  <cfset config.hooks = arrayNew(1)>
</cfif>
<!--- (Step 1) Register the CKFinderPluginFileSize function to be called by the BeforeExecuteCommand hook. --->
<cfset hook = arrayNew(1)>
<cfset hook[1] = "BeforeExecuteCommand">
<cfset hook[2] = "CKFinderPluginFileSize">
<cfset ArrayAppend(config.hooks, hook)>
<cfset ArrayAppend(config.plugins, 'myplugin')>

Step1: Register an event handler

<cfset hook = arrayNew(1)>
<cfset hook[1] = "BeforeExecuteCommand">
<cfset hook[2] = "CKFinderPluginFileSize">
<cfset ArrayAppend(config.hooks, hook)>

Step2: Create an event handler

Our event handler defined in (1) is called "CKFinderPluginFileSize", so let's define such function.

<cffunction name="CKFinderPluginFileSize" returntype="Boolean" output="true">
// ...

Step3: Create a class

Instead of writing everything in plugin.cfm, we'll create another file, called FileSize.cfc, where we'll add the rest of the code.

If your plugin returns an XML response, you'll usually just extend the XmlCommandHandlerBase component to reduce the amount of code to write, however it is not a requirement.

<cfcomponent output="false" extends="CKFinder_Connector.CommandHandler.XmlCommandHandlerBase">

Step4: Create the buildXml method

In the CKFinderPluginFileSize function we have called sendResponse. The sendResponse method is defined in XmlCommandHandlerBase class, it creates a basic XML response and calls the buildXml method, which we need to define in FileSize.cfc.

<cffunction access="public" name="buildXml" hint="send XML response" returntype="boolean" description="send response" output="false">
// ...

Step5: Construct the XML response

The main task of the buildXml method is to construct an XML response, so we're doing it below:

nodeFileSize = XMLElemNew(THIS.xmlObject, "FileSize");
nodeFileSize.xmlAttributes["size"] = myDir.Size;
ArrayAppend(THIS.xmlObject["Connector"].xmlChildren, nodeFileSize);

Full source code

The full source code of a plugin with all necessary security checks:

plugin.cfm
<cffunction name="CKFinderPluginFileSize" returntype="Boolean" output="true">
  <cfargument name="command" required="true" type="String">
  <!--- (3) Register the "FileSize" command --->
  <cfif command eq "FileSize">
    <cftry>
      <cfset oObject = CreateObject("component", "FileSize")>
      <!---
      The sendResponse method is defined in XmlCommandHandlerBase, it creates 
      a basic XML response and calls the buildXml()method 
      --->
      <cfset oObject.sendResponse()>
      <cfcatch type="ckfinder">
        <!--- If an exception occurred, send an error in the XML format --->
        <cfscript>
          oCommandHandler_XmlCommandHandler = 
            APPLICATION.CreateCFC("CKFinder_Connector.CommandHandler.XmlCommandHandlerBase").Init();
          oCommandHandler_XmlCommandHandler.sendError(#CFCATCH.ErrorCode#);
        </cfscript>
      </cfcatch>
    </cftry>
    <!--- false = stop further execution --->
    <cfreturn false>
  <cfelse>
    <cfreturn true>
  </cfif>
</cffunction>

<cfset REQUEST.CKFinderPluginFileSize = CKFinderPluginFileSize>

<!--- Make sure that both arrays exist --->
<cfif not structkeyexists(config, "plugins")>
  <cfset config.plugins = arrayNew(1)>
</cfif>
<cfif not structkeyexists(config, "hooks")>
  <cfset config.hooks = arrayNew(1)>
</cfif>
<!--- (1) Register the CKFinderPluginFileSize function to be called by the BeforeExecuteCommand hook. --->
<cfset hook = arrayNew(1)>
<cfset hook[1] = "BeforeExecuteCommand">
<cfset hook[2] = "CKFinderPluginFileSize">
<cfset ArrayAppend(config.hooks, hook)>
<cfset ArrayAppend(config.plugins, 'myplugin')>
FileSize.cfc
<!--- Since we will send a XML response, we'll extend the XmlCommandHandlerBase --->
<!--- (2) Extend base XML command handler --->
<cfcomponent output="false" extends="CKFinder_Connector.CommandHandler.XmlCommandHandlerBase">

<!--- (4) The buildXml method is used to construct an XML response --->
<cffunction access="public" name="buildXml" hint="send XML response" returntype="boolean" description="send response" output="false">
	<cfset var fileName = URL.FileName>
	<cfset var fileSystem = APPLICATION.CreateCFC("Utils.FileSystem") />
	<cfset var coreConfig = APPLICATION.CreateCFC("Core.Config")>
	<cfset var currentFolderServerPath = THIS.currentFolder.getServerPath()>
	<cfset var filePath = fileSystem.CombinePaths(currentFolderServerPath, fileName)>

	<cfif not REQUEST.CheckAuthentication()>
		<cfthrow errorCode="#REQUEST.constants.CKFINDER_CONNECTOR_ERROR_CONNECTOR_DISABLED#" type="ckfinder" />
	</cfif>

	<cfif not THIS.currentFolder.checkAcl(REQUEST.constants.CKFINDER_CONNECTOR_ACL_FILE_VIEW) >
		<cfthrow errorcode="#REQUEST.constants.CKFINDER_CONNECTOR_ERROR_UNAUTHORIZED#" type="ckfinder" />
	</cfif>

	<cfif not fileSystem.checkFileName(fileName) or coreConfig.checkIsHiddenFile(fileName)>
		<cfthrow errorcode="#REQUEST.constants.CKFINDER_CONNECTOR_ERROR_INVALID_REQUEST#" type="ckfinder">
	</cfif>

	<cfset result = THIS.currentFolder.checkExtension(fileName)>
	<cfif not result[1]>
		<cfthrow errorcode="#REQUEST.constants.CKFINDER_CONNECTOR_ERROR_INVALID_REQUEST#" type="ckfinder">
	</cfif>

	<cfif not fileexists(filePath)>
		<cfthrow errorcode="#REQUEST.constants.CKFINDER_CONNECTOR_ERROR_FILE_NOT_FOUND#">
	</cfif>

	<cfdirectory name="myDir" action="list" directory="#currentFolderServerPath#" filter="#fileName#">
	<cfscript>
		// (5) Adding a <FileSize> element to the XML response.
		nodeFileSize = XMLElemNew(THIS.xmlObject, "FileSize");
		nodeFileSize.xmlAttributes["size"] = myDir.Size;
		ArrayAppend(THIS.xmlObject["Connector"].xmlChildren, nodeFileSize);
	</cfscript>

	<cfreturn true>
</cffunction>

</cfcomponent>
plugin.js

.. and the client side (JavaScript) plugin that will call the FileSize command: (save the code as plugin.js in "plugins/myplugin" folder)

CKFinder.addPlugin( 'myplugin', function( api ) {
	api.addFileContextMenuOption( { label : 'File Size', command : "FileSize" } , function( api, file )
	{
		api.connector.sendCommand( 'FileSize', { fileName : api.getSelectedFile().name }, function( xml )
		{
			if ( xml.checkError() )
				return;

			var size = xml.selectSingleNode( 'Connector/FileSize/@size' );
			api.openMsgDialog( "", "The exact size of a file is: " + size.value + " bytes");
		} );
	});
});