Open a new tab/window and write something to it?

Question

I'm using Execute JS to write and test Javascript code within Firefox. I want to open a new tab/window and write something to it and I tried

var wm = Components.classes["@mozilla.org/appshell/window-mediator;1"].getService(Components.interfaces.nsIWindowMediator);
var win = wm.getMostRecentWindow("navigator:browser");
printWindow = win.open("about:blank");
printWindow = wm.getMostRecentWindow("navigator:browser");
printWindow.gBrowser.selectedBrowser.contentDocument.write('hello');

And

myWindow=window.open('','','width=200,height=100')
myWindow.document.write("<p>This is 'myWindow'</p>")
myWindow.focus()

However I always get this error

[Exception... "The operation is insecure." code: "18" nsresult: "0x80530012 (SecurityError)"

Is there any way to get through this exception?

Fabrin

"Exception: The operation is insecure" is a bug on Firefox default console (bugzilla.mozilla.org/show_bug.cgi?id=663406), it doesn't happen with Firebug console on Firefox and Chromium default console, I commented here #12899028 – Eld

Answer 1

Edit: As of 2018, this solution no longer works. So you are back to opening about:blank in a new window and adding content to it.

Don't "write" to the window, just open it with the contents you need:

var data = "<p>This is 'myWindow'</p>";
myWindow = window.open("data:text/html," + encodeURIComponent(data),
                       "_blank", "width=200,height=100");
myWindow.focus();

For reference: data URIs

Pepys

Thanks a lot the code is working fine but I'm wondering how can I append new data to this newly opened window? – Fabrin

Use DOM methods? – Pepys

So I try this code pastebin.com/n1znvdYk like you tell me but it seems that the new element is not appended to the document at all. Can you fix this for me please? – Fabrin

@user433531: Give the window a chance to load? myWindow.addEventListener("load", ..., false) – Pepys

I've got a ton of data to write and Firefox just hangs ("Not Responding") in Windows. :-( – Octavalent

@user2259571: Not really a reason to downvote a perfectly good solution. – Pepys

The solution doesn't work for me (or at least not for my purpose). That's as good a reason to downvote as any isn't it? – Octavalent

@user2259571: The solution is correct, it solves the problem. What you are talking about needs to be filed under bugzilla.mozilla.org (assuming that the issue isn't caused by extensions). – Pepys

Firefox is starting to block top-level navigation to data URLs - the browser will immediately close the new window. See blog.mozilla.org/security/2017/11/27/… – Leucocytosis

Chrome has also blocked it: chromestatus.com/feature/5669602927312896 – Leucocytosis

if you want open in new tab on the same browser its enough to put in javascript: open( 'http://www.someth.com ', '',''); – Velure

This is not working anymore, maybe something changed in Google Chrome. – Dorsad

Answer 2

Top-level navigation to data URLs has been blocked in Chrome, Firefox (with some exceptions), IE, and Edge (and likely other browsers to boot). They are apparently commonly used for phishing attacks, and major browser vendors decided that the danger outweighed the value provided by legitimate use cases.

This Mozilla security blog post explains that Firefox will block

• Web page navigating to a new top-level data URL document using:
  • window.open("data:…");
  • window.location = "data:…"
  • clicking <a href="data:…"> (including ctrl+click, ‘open-link-in-*’, etc).
• Web page redirecting to a new top-level data URL document using:
  • 302 redirects to "data:…"
  • meta refresh to "data:…"
• External applications (e.g., ThunderBird) opening a data URL in the browser

but will not block

• User explicitly entering/pasting "data:…" into the address bar
• Opening all plain text data files
• Opening "data:image/*" in top-level window, unless it’s "data:image/svg+xml"
• Opening "data:application/pdf" and "data:application/json"
• Downloading a data: URL, e.g. ‘save-link-as’ of "data:…"

You can also read the proposal to deprecate and remove top-frame navigation to data URLs in Chrome and view the current Chrome status indicating that is has been removed.

As for how to actually open HTML in a new tab or window, this should be sufficient:

var tab = window.open('about:blank', '_blank');
tab.document.write(html); // where 'html' is a variable containing your HTML
tab.document.close(); // to finish loading the page

Note that at least in Chrome, external scripts injected via document.write might not be loaded on slower connections. That might not be relevant here, but something to watch out for.

Leucocytosis

This will open the address that you are currently on in a new tab. You probably meant window.open("about:blank", "_blank"). Also, the browser will switch to the new tab automatically, calling .focus() is pointless. – Pepys

Gotcha - thanks for the info! I'll go ahead and make that edit (and adopt it into my own code). Thanks for fixing my formatting, as well. – Leucocytosis

This is the first working solution for me. I am trying it on Google Chrome – Dorsad

What if I don't use tab.document.close(); ? – Cumber

Answer 3

var winPrint = window.open('', '', 'left=0,top=0,width=800,height=600,toolbar=0,scrollbars=0,status=0');
winPrint.document.write('<title>Print  Report</title><br /><br />    Hellow World');
winPrint.document.close();

window.open(uri) does not work in chrome as of 2018

Quadragesima

URIs in general aren't being blocked - data URLs are. Apparently they are commonly used for phishing attacks. Both Chrome and Firefox are blocking it - see the Mozilla security blog post, the Chrome intent to deprecate and remove post, and the Chrome status post indicating that it has been removed. – Leucocytosis

Uncaught SyntaxError: Invalid or unexpected token – Gnarl

Answer 4

This is the code I found to work when trying to create custom windows in JavaScript. `

function createPage(){
    let pageCode = "<p>Hello, World!</p>"
    let page = window.open()
    page.document.write(pageCode)
}

`

Also when creating a new window you're actually creating a tab not a different window.

Esbenshade