/*

    File: content.js

Abstract: Injected JavaScript file.

 Version: 1.0

Disclaimer: IMPORTANT:  This Apple software is supplied to you by Apple

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terms, and your use, installation, modification or redistribution of

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In consideration of your agreement to abide by the following terms, and

subject to these terms, Apple grants you a personal, non-exclusive

license, under Apple's copyrights in this original Apple software (the

"Apple Software"), to use, reproduce, modify and redistribute the Apple

Software, with or without modifications, in source and/or binary forms;

provided that if you redistribute the Apple Software in its entirety and

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text and disclaimers in all such redistributions of the Apple Software.

Neither the name, trademarks, service marks or logos of Apple Inc. may

be used to endorse or promote products derived from the Apple Software

without specific prior written permission from Apple.  Except as

expressly stated in this notice, no other rights or licenses, express or

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The Apple Software is provided by Apple on an "AS IS" basis.  APPLE

MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION

THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS

FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND

OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS.

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OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

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Copyright (C) 2010 Apple Inc. All Rights Reserved.

*/

// Register for the beforeload events. The beforeload event fires for all sub-resources

// (scripts, stylesheets, iframes, images, plug-ins, etc.)

document.addEventListener("beforeload", handleBeforeLoadEvent, true);

function loadContent(event)

{

    const element = event.target;

    // Restore the original className.

    element.className = element.className.replace(" blocked-content", "");

    // Remove the click event listener.

    element.removeEventListener("click", loadContent, true);

    // Mark the element as allowed to load. This property is used by handleBeforeLoadEvent.

    element.allowedToLoad = true;

    // Remove the element and reinsert it to trigger a load.

    var nextSibling = element.nextSibling;

    var parentNode = element.parentNode;

    parentNode.removeChild(element);

    parentNode.insertBefore(element, nextSibling);

    // Stop event propagation and prevent the default action so the click does not trigger

    // anything else in the page, like following a link.

    event.stopPropagation();

    event.preventDefault();

}

function handleBeforeLoadEvent(event)

{

    const element = event.target;

    // Return early, allowing the load to occur, if the element has the allowedToLoad property.

    // This property is set in loadContent when the element is clicked.

    if (element.allowedToLoad)

        return;

    // Call up to the global page using the special canLoad function. This sends a

    // synchronous message event, so it blocks while waiting for an answer.

    // If canLoad returns true return early, allowing the load to occur.

    if (safari.self.tab.canLoad(event, { url: event.url, nodeName: element.nodeName }))

        return;

    // Since the load should be blocked, call preventDefault on the event to block it.

    event.preventDefault();

    // Add the 'blocked-content' class so our injected style will style this element.

    element.className += " blocked-content";

    // Add a click event listener so when the user clicks the element we can load the content.

    // It is a capture event listener (true for the third argument) so we get first chance

    // to handle the click, so images inside links don't follow the link for the first click.

    element.addEventListener("click", loadContent, true);

}