Sending data between XUL components

Question

I have an extension consisting of a browser overlay (ff-overlay.xul) that launches a sidebar (ff-sidebar.xul) through this code (from the Mozilla extension generator): (in ff-overlay.xul)

<menupopup id="viewSidebarMenu">
    <menuitem key="key_openSidebar_testinstallPackage" observes="viewSidebar_testinstallPackage" />
</menupopup>

<keyset id="mainKeyset">
    <key id="key_openSidebar_testinstallPackage" command="viewSidebar_testinstallPackage" />
</keyset>

<broadcasterset id="mainBroadcasterSet">
    <broadcaster id="viewSidebar_testinstallPackage"
        label="&testinstallPackageSidebar.label;"
        autoCheck="false"
        type="checkbox"
        group="sidebar"
        sidebarurl="chrome://testinstallPackage/content/ff-sidebar.xul"
        sidebartitle="&testinstallPackageSidebar.label;"
        oncommand="toggleSidebar('viewSidebar_testinstallPackage');" />
</broadcasterset>

The main overlay has a js code in overlay.js: (in ff-overlay.xul)

<script src="overlay.js"/>

The xul sidebar has js code in ff-sidebar.js: (in ff-sidebar.xul)

<script src="ff-sidebar.js"/>

I need to send some data (enough String) from overlay.js to ff-sidebar.js

I tried this one , but it didn’t work (and I don’t know if it could work, it should be between the main overlay and the current page).

Please provide me some meaning for this.

Answer 1

https://developer.mozilla.org/en/Working_with_windows_in_chrome_code, .

Answer 2

nsIWindowMediator . overlay.js ff-sidebar.js, window.QueryInterface :

OVERLAY.JS

var shell = {
message : function(){
       var msg = "Hello";
       return msg;
}
}

FF-SIDEBAR.JS

// put this in the function that is executed when the sidebar loads preferably 
var mainWindow = window.QueryInterface(Components.interfaces.nsIInterfaceRequestor)
               .getInterface(Components.interfaces.nsIWebNavigation)
               .QueryInterface(Components.interfaces.nsIDocShellTreeItem)
               .rootTreeItem
               .QueryInterface(Components.interfaces.nsIInterfaceRequestor)
               .getInterface(Components.interfaces.nsIDOMWindow);
alert(mainWindow.shell.message); //this will alert Hello

, .