Integrating CKEditor with a Custom File Browser

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CKEditor can be easily integrated with your own file browser.

To connect a file browser that is already compatible with CKEditor (like CKFinder), follow the File Browser (Uploader) documentation.

Interaction Between CKEditor and File Browser

CKEditor automatically sends some additional arguments to the file browser:

  • CKEditor – name of the CKEditor instance,
  • langCode – CKEditor language (en for English),
  • CKEditorFuncNum – anonymous function number used to pass the URL of a file to CKEditor (a random number).
CKEditor=editor1&CKEditorFuncNum=1&langCode=en

Example 1

Suppose that CKEditor was created using the following JavaScript call:

CKEDITOR.replace( 'editor2',
    {
        filebrowserBrowseUrl : '/browser/browse.php?type=Images',
        filebrowserUploadUrl : '/uploader/upload.php?type=Files'
    });

In order to browse files, CKEditor will call:

/browser/browse.php?type=Images&CKEditor=editor2&CKEditorFuncNum=2&langCode=de

The call includes the following elements:

  • /browser/browse.php?type=Images – the value of the filebrowserBrowseUrl parameter,
  • &CKEditor=editor2&CKEditorFuncNum=2&langCode=de – the information added by CKEditor:
    • CKEditor=editor2 – the name of a CKEditor instance (editor2),
    • CKEditorFuncNum=2 – the number of anonymous function that should be used in the CKEDITOR.tools.callFunction,
    • langCode=de – language code (in this case: German). This parameter can be used to send localized error messages.

Passing the URL of the Selected File

To send back the file URL from an external file browser, call CKEDITOR.tools.callFunction and pass CKEditorFuncNum as the first argument:

window.opener.CKEDITOR.tools.callFunction( funcNum, fileUrl [, data] );

If data (the third argument) is a string, it will be displayed by CKEditor. This parameter is usually used to display an error message if a problem occurs during the file upload.

Example 2

Sending the url from file browser (JavaScript):

// Helper function to get parameters from the query string.
function getUrlParam(paramName)
{
  var reParam = new RegExp('(?:[\?&]|&)' + paramName + '=([^&]+)', 'i') ;
  var match = window.location.search.match(reParam) ;

  return (match && match.length > 1) ? match[1] : '' ;
}
var funcNum = getUrlParam('CKEditorFuncNum');
var fileUrl = '/path/to/file.txt';
window.opener.CKEDITOR.tools.callFunction(funcNum, fileUrl);

Example 3

Sending back the url of uploaded file from PHP connector:

<?php
// Required: anonymous function number as explained above.
$funcNum = $_GET['CKEditorFuncNum'] ;
// Optional: instance name (might be used to load specific configuration file or anything else)
$CKEditor = $_GET['CKEditor'] ;
// Optional: might be used to provide localized messages
$langCode = $_GET['langCode'] ;

// Check the $_FILES array and save the file. Assign the correct path to some variable ($url).
$url = '/path/to/uploaded/file.ext';
// Usually you will assign here something only if file could not be uploaded.
$message = '';

echo "<script type='text/javascript'>window.parent.CKEDITOR.tools.callFunction($funcNum, '$url', '$message');</script>";
?>
Note: the information below applies to CKEditor rev 4940+ (current nightly build, CKEditor 3.1.1+/3.2+ (not available at the moment of writing this part of documentation - 18 Jan 2010))

If data is a function, it will be executed in the scope of a button that called the file browser. It means that the server connector can directly access CKEditor and the dialog box to which this button belongs.

Example 4

Suppose that apart from passing the fileUrl value that is assigned to appropriate filed automatically based on the dialog definition, you want also to set the "alt" attribute if the file browser was opened in the Image dialog. In order to do this, simply pass an anonymous function as a third argument:

window.opener.CKEDITOR.tools.callFunction( funcNum, fileUrl, function() {
  // Get the reference to a dialog.
  var element, dialog = this.getDialog();
  // Check if it is an Image dialog.
  if (dialog.getName() == 'image') {
    // Get the reference to a text field that holds the "alt" attribute.
    element = dialog.getContentElement( 'info', 'txtAlt' );
    // Assign the new value.
    if ( element )
      element.setValue( alt );
  }
  ...
  // Return false to stop further execution - in such case CKEditor will ignore the second argument (fileUrl)
  // and the onSelect function assigned to a button that called the file browser (if defined).
  [return false;]
});