MenuEvent.selectionText

This functionality has not landed in a stable Opera version yet, but you can use it already in Opera Next.

Description:

The selectionText attribute is the run of text selected by the user. If the user has not selected any text then this attribute will be null.

Syntax:

readonly DOMString selectionText

Example:

In this example, a menu item is added to the context menu only when the user selects some text. When the menu item is clicked, the selected text is searched for at Wiktionary.org.

<!-- 
  The configuration file ('config.xml').
-->
<?xml version='1.0' encoding='utf-8'?>
<widget xmlns="http://www.w3.org/ns/widgets">
    ...
    <feature name="opera:contextmenus"/>
    ...
</widget>

//
// The background process (e.g. '/background.js'). 
//

if (opera.contexts.menu) {
  var menu = opera.contexts.menu;
  
  // Create a menu item properties object
  var itemProps = {
    contexts: ['selection'],
    title: 'Find in Wiktionary',
    onclick: function(event) {
      var query = encodeURIComponent(event.selectionText);
      
      // Create a tab properties object
      var tabProps = {
        url: 'http://www.wiktionary.org/wiki/' + query
      };

      // Create a tab with the specified properties
      var tab = opera.extension.tabs.create(tabProps);
    }
  }

  // Create a menu item with the specified properties
  var item = menu.createItem(itemProps);
  // Add the menu item to the context menu
  menu.addItem(item);
}