(TamperMonkey) View full resolution images on Instagram

IgFull.js

// ==UserScript==
// @name         IG Fullsize (mod by Wappen)
// @version      0.7
// @description  View full resolution images on Instagram
// @match        https://www.instagram.com/*
// @require      https://gist.githubusercontent.com/realies/2fece0cd3e197cf6b31ca1316431a2a4/raw/debc0e6d4d537ac228d1d71f44b1162979a5278c/waitForKeyElements.js
// @author       realies, mod by Wappen
// ==/UserScript==
(() => {
    waitForKeyElements("div._aagu", clickBox => {
        clickBox.style.cursor = "zoom-in";
        clickBox.onclick = () => _OnOpenJumbo( clickBox );
    }, false);
})();

function _OnOpenJumbo( aagu )
{
    let a = aagu.querySelector("img");
    if( a == null )
        return;

    // Default is using src image
    let url = a.src;

    // Access biggest image in srcset
    if( a.srcset != null && a.srcset.length > 0 )
    {
        // https://stackoverflow.com/questions/36541892/how-to-determine-highest-resolution-image-from-srcset
        var biggestImage = "";
        var highestPixelDensity = 1;
        for (var descriptor of a.srcset.split(/,/))
        {
            var parts = descriptor.trim().split(/ /);

            // Here we check only for pixel density, see later for
            // width descriptor but code is straightforward
            var pixelDensity = parseFloat(parts[1].substring(-1));
            if (pixelDensity > highestPixelDensity)
            {
                biggestImage = parts[0];
                highestPixelDensity = pixelDensity;
            }
        }
        if( biggestImage != null )
            url = biggestImage;
    }

    window.open( url );
}

Update 0.7

• Fix error for img with blank srcset such as https://www.instagram.com/p/Cm4QF6UPVtp/