Redirect URL from local filesystem to internet with FireFox extension

Question

I have several PDF files on my computer that contain links to other pages. Those links, however, direct you to the local filesystem instead of the internet. I.e. clicking the link opens the browser and takes you to file:///page instead of http://domain/page.

Getting these files modified to include the full URL is not an option.

I tried using available Firefox extensions to redirect the URL, but none worked, so I tried creating my own extension to do the same. What I've found so far is that the URL isn't accessible until the tab's "ready" event fires, but a page referring to a local file without the full path is always "uninitialized."

Here's my extension script, almost straight from https://developer.mozilla.org/en-US/Add-ons/SDK/High-Level_APIs/tabs:

var tabs = require("sdk/tabs");
tabs.on('open', function(tab){
    tab.on('ready', function(tab){
        if (tab.url.indexOf("file:///page") != -1) {
            tab.url = tab.url.replace("file://", "https://domain");
        }
    });
});

Any ideas how to go about redirecting a page from a local file to another location?

Good question and I'm eager to see a reply as well. Using `http-on-modify-request` probably doesn't catch this as it's a file uri right? If that doesn't work then I think the way to go is `nsIWebProgressListener` but that is non-sdk, and it looks like you are doing an SDK addon. Lets hold out to see if an SDK dev can enlighten us otherwise I'll share with you the nsIWebProgressListener, you can get a jump start by reading about it here: https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XPCOM/Reference/Interface/nsIWebProgressListener — Noitidart, Oct 01 '15 at 23:12

score 1 · Answer 1 · answered Oct 03 '15 at 10:37

The following snippet works fine with me. In main.js:

var tabs = require("sdk/tabs");
tabs.on('ready', function(tab){
    var new_url = tab.url;
    if (tab.url.indexOf("file:///") != -1) {
        new_url = new_url.replace("file:///", "https://domain/");
        tab.url = new_url;
    }
});

Although, my Firefox didn't fire the ready event on my tab when the url is something like what you want. For example, when the url is file:///page/lala.pdf, firefox ignores the url and does not try to reach it. I believe Firefox wants a "real" path to load the page such as file:///C:page/lala.pdf.

I hope this will help you.

Yes, when you refer to a local file and include the full path, i.e. C:..., you get a "File not Found" error, and the URL can be retrieved. Unfortunately, the links in the files are simply relative and so do not include the full path. You therefore get `file:///page/lala.aspx?.....` with a ready state of "uninitialized" and a URL of "about:blank". — Daniel H, Oct 05 '15 at 16:26

score 1 · Accepted Answer · edited May 23 '17 at 11:58

The easiest way I've found to do this is actually from another StackOverflow answer... Get Content of Location Bar. Use the function in that answer to retrieve the URL and then redirect based on that. So I end up with the following:

var tabs = require("sdk/tabs");
tabs.on('open', function(tab){
    tab.on('activate', function(tab){
        var { getMostRecentWindow } = require("sdk/window/utils");
        var urlBar = getMostRecentWindow().document.getElementById('urlbar');
        if (urlBar.value.indexOf("file:///page/") != -1) {
            tab.url = urlBar.value.replace("file://", "https://domain");
        }
    });
});

Redirect URL from local filesystem to internet with FireFox extension

2 Answers2

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