CKEDITOR.dialog.definition.contentObject

This class is not really part of the API. It is the template of the objects representing content pages inside the CKEDITOR.dialog.definitionObject.

CKEDITOR.on( 'dialogDefinition', function( evt ) {
    var definition = evt.data.definition;
    var content = definition.getContents( 'page1' );
    content.remove( 'textInput1' );
    // ...
} );