login with (firefox) remembered mal account data automatically, also ultimate destination for animelist.

mal-autologin.user.js

// ==UserScript==
// @name        mal_auto_login
// @namespace   tkscripts
// @description login with (firefox) remembered mal account data automatically, also ultimate destination for animelist
// @include     http://myanimelist.net/*
// @require     http://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js
// @version     1.1
// @grant       none
// ==/UserScript==

// Author: Tuomas Kinnunen

// This is GreaseMonkey UserScript for firefox

//THE SCRIPT IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND.

// NOTE: You can't log out when this is on.

this.$ = this.jQuery = jQuery.noConflict(true);

$(function() {
  function test(target) {
    return typeof target !== "undefined" && target !== null
  }

  function gotoLogin(loginLink){
    if (test(loginLink)) {
      console.log('mal autologin: loggin in with link: ' + loginLink);
      window.location.href = loginLink;
    }
  }

  function tryLogin() {
    var form = $('form[action="http://myanimelist.net/login.php"]');
    console.log('mal autologin: try login');
    if ($('input[name="username"]').val().length > 0
     && $('input[name="password"]').val().length > 0) {
      console.log('mal autologin: submitting');
      form.submit();
      return true;
    } else {
      return false;
    }
  };


  var pageurl = window.location.href;


  if (pageurl.startsWith("http://myanimelist.net/animelist/")) {
    // save ultimate destination
    window.sessionStorage.udestination = window.location.href;

    // should be ok even if mal makes minor updates
    var loginLink = $('a:contains("Login"),a:contains("Log in")').attr('href'); 
    gotoLogin(loginLink);


  } else if (pageurl.startsWith("http://myanimelist.net/panel.php")) {
    // Login ends up here; execute ultimate destination
    
    if (test(window.sessionStorage.udestination)) {
      var dest = window.sessionStorage.udestination;
      console.log('mal autologin: go to ultimate destination: ' + dest);

      delete window.sessionStorage.udestination;

      window.location.href = dest;
    }


  } else if (pageurl.startsWith("http://myanimelist.net/login.php")) {

    if (tryLogin()) return;
    
    // not sure if this is needed; it's for waiting that browser inserts the user and pass.
    window.setTimeout(tryLogin, 120);



  } else if (pageurl.startsWith("http://myanimelist.net/ajaxtb.php")) {

    if (tryLogin()) return;
    
    // not sure if this is needed; it's for waiting that browser inserts the user and pass.
    window.setTimeout(tryLogin, 120);



  } else {
    var loginLink = $('a:contains("Login"),a:contains("Log in")').attr('href');
    gotoLogin(loginLink);

  }

});

Nice script. It should return the user to the page they were on previously though.