Chrome扩展程序，通过php将大变量传递到其他Windows

I'm currently writing a Chrome Extension that takes user selected data and passes it to another window. Aside from the manifest.json files, I have a background.js and index.php file.

The background.js file successfully grabs the user selected data, opens a new broswer window, and then passes the user selected data to the index.php file located on a server via $_GET. This works great until you exceed a certain character limit in which case you get an error saying the url is too long. I was wondering if there was anyway to send the data from the background.js file to the new window using $_POST or any other method that would allow larger data selections? Or could I just pass the user selected data to the new window first, and then have that window access the server?

background.js

function getClickHandler() {
  return function(info, tab) {

      var tx =  info.selectionText;
      tx = encodeURIComponent(tx);

    // Create a new window to the info page.
      var url = 'http://192.168.0.22?tx=' + tx;

    chrome.windows.create({url: url, width: 500, height: 760 });
  };
};


chrome.contextMenus.create({
  "title" : "Store",
  "type" : "normal",
  "contexts" : ["selection"],
  "onclick" : getClickHandler()
});

index.php

<?php 

$text = $_GET['tx'];
print ($text);

?>

Potentially you could create a form dynamically and then set an input to the value you're trying to send as a query-string-parameter.

Something like:

var $form  = $('<form action="' + url + '" method="POST" target="_blank" />'),
    $input = $('<input name="tx" type="text" />').val(tx);

$form.append($input).trigger("submit");

Without running the code I'm not sure if the submit will function without adding the form to the DOM, if not then you'll need to append the form to the DOM and then trigger submit, after which you probably want to remove the form from the DOM.

I say potentially because I'm not familiar with writing Chrome Extensions but I've done this as part of a normal web-app before and it worked.