Access within iframes

I'm using a short snippet of linkify derived code to access all the text inodes within a webpage from a Firefox extension. This looks like this, so nothing particularly interesting:

var notInTags=[
    'a', 'head', 'noscript', 'option', 'script', 'style', 'title', 'textarea'
    ];

    var xpath = ".//text()[not(ancestor::"+notInTags.join(') and not(ancestor::')+")]";

    var candidates = window.content.document.evaluate(xpath, window.content.document, null, XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE, null);

Does anyone have a suggestion on the best way to grab the text nodes from any iframes present as well pl开发者_如何学编程ease? Specifically, is using

iframe.window.content.document

likely to get me anywhere (Doesn't seem to), or am I am I barking up the wrong tree?

Cheers :)

Edit 2: This is the complete updated function (again)

    rsfindmod.searchiframes= function(candidates){
//This fixes cases where a redirecting page uses frames (Primarily search engines etc)
    const urlRegex = /\b(https?:\/\/[^\s+\"\<\>]+)/ig;
    var framesets = window.content.document.getElementsByTagName('frame','iframe','frameset');

    for (var i = 0; i < framesets.length; i++) {
    if (urlRegex.test(framesets[i])) {
    alert('test');
    var document2 = framesets[i].contentDocument;
    var notInTags=[
    'a', 'head', 'noscript', 'option', 'script', 'style', 'title', 'textarea'
    ];

    var xpath = ".//text()[not(ancestor::"+notInTags.join(') and not(ancestor::')+")]";

    var textnodes = document2.evaluate(xpath, document2, null, XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE, null);
    for(var i = 0; i < textnodes.length; i++) {
        candidates.push(textnodes[i]);
    }
}   
}
}

Edit 3: A slightly better function?

rsfindmod.searchiframes= function(candidates, frame, documentList){
//This fixes cases where a redirecting page uses frames (Primarily search engines etc)
    const framesets = frame.frames;

    for (var i = 0; i < framesets.length; i++) {
    var document2 = framesets[i].contentWindow.document;
    var notInTags=[
    'a', 'head', 'noscript', 'option', 'script', 'style', 'title', 'textarea'
    ];
    alert('test');
    var xpath = ".//text()[not(ancestor::"+notInTags.join(') and not(ancestor::')+")]";

    var textnodes = document2.evaluate(xpath, document2, null, XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE, null);
    for(var i = 0; i < textnodes.length; i++) {
        candidates.push(textnodes[i]);
        alert('test1'); 
    }

}
}

You want iframe.contentDocument (or iframe.contentWindow.document, but the former is simpler).