EnvJS/Rhino, setTimeout() not working

Question

I currently set up EnvJS on my system (installed from here). My end goal is to load a page let it's javascript process for a few seconds, and then read the dom to get the information of interest. However I can not get setTimeout() to work to save my life (Or JQuery for that matter).

I have a php script that starts the process:

...
$ENVJS_PATH = "/var/www/project/src/envjs";
$RHINO_JAR = "rhino/js.jar";
$INIT_SCRIPT = "init.js";
$output = shell_exec("java -jar $ENVJS_PATH/$RHINO_JAR -opt -1 $ENVJS_PATH/$INIT_SCRIPT");
echo "Response from javascript:<br/> $output";
...

the init.js file looks like:

load('/var/www/project/src/envjs/dist/env.rhino.js');
print("Loaded env.rhino.js<br/>");

// temporarily commented out
//var url = "http://www.ken-soft.com";
//window.location = url;
//print("<br/>Loaded "+url+"<br/>");

// Problem starts here
var runAfterPause=function() {
  print("got here..."); // never gets called
  print(document.getElementById('some_id').innerHTML);
}
setTimeout(runAfterPause, 3000); //wait three seconds before continuing
// i have also tried setTimeout("runAfterPause()", 3000);
print("<br/>End<br/>");

Any knowledge on this would be much appreciated. Thanks.

Towhee

Have you found a solution to this problem? – Brooklet

not yet. I need to try out your answer. but I am spending a few days on another task, then I will get back to it. Sorry for not promptly trying your recommendations. I will try them as soon as I have free time. :) – Towhee

Answer 1

Try env.rhino.1.2.js - and if the server OS hosting rhino is Ubuntu, then try sudo apt-get install rhino -- and call rhino -opt -1 ... instead of java -jar ...

Seems to run like this for me on Ubuntu 11.04, when ran directly on the shell - not sure if PHP's shell_exec may influence things or not..

EDIT: Indeed it is not really working; I looked through the source a bit, and could see that setTimeout relies on Timer.prototype.start = function(){};, which is apparently empty. Browsing further, the only thing that seems to deal with timing is Envjs.wait() - and using that, I can finally get a sort of a timed loop; however, note that it seems to be strictly single-threaded (synchronous) now:

print("loading " + 1.2);
load('env.rhino.1.2.js'); // takes a while ...
print("loaded " + 1.2);
console.log(window);

var c=0;
function timedCount() // like this, when setTimeout calls a string!
{
  c=c+1;
  print("c=" + c);

  if (c<10) // make a limit for the run of script:
  {
    var t;
    //~ t=window.setTimeout(timedCount(),100); // TypeError: fn is not a function, it is undefined.
    t=window.setTimeout("timedCount()",1000); // must have `t=...` - else it locks on return even w/ wait(0)!
    Envjs.wait(); // waits, but "timer error  undefined   TypeError: fn is not a function, it is undefined." if setTimout doesn't call string; wait(0) exits immediately
  } else Envjs.wait(0); // "reset": execute all timers and return; else here will be left hanging from previous wait()
}



// main:

timedCount();
//~ eval("timedCount()", null); // works the same

print("after timedCount()");

... and the results are:

$ sudo apt-get install rhino
$ wget https://github.com/thatcher/env-js

$ rhino -opt -1 test.js
loading 1.2
[  Envjs/1.6 (Rhino; U; Linux i386 2.6.38-11-generic; en-US; rv:1.7.0.rc2) Resig/20070309 PilotFish/1.2.13  ]
loaded 1.2
[Window]
a
c=1
c=2
c=3
c=4
c=5
c=6
c=7
c=8
c=9
c=10
after timedCount()

If I recall correctly, in a browser setInterval is asynchronous/multithreaded - indeed, in a browser JavaScript Shell 1.4, the almost same code:

var c=0;
function timedCount() 
{
  c=c+1;
  print("c=" + c);

  if (c<10)  {
    var t;
    t=window.setTimeout("timedCount()",1000); 
  }
}

timedCount();
print("after timedCount()");

produces:

c=1
after timedCount()
c=2
c=3
c=4
c=5
c=6
c=7
c=8
c=9
c=10

Gregorygregrory

Answer 2

The callback method is defined after the assignation. Try putting it before setTimeout

Lamar

Sorry about that. I copied and pasted incorrectly :P My actual code has it in the right order.(I just edited the post) – Towhee

Another thing worth commenting on is that setTimeout( "print('x');", 1000 ); doesn't do anything either. – Towhee

Answer 3

print is a method of window.

It's used to print a page, with a printer...

There might be a conflict with it and your print method.

Lamar

print() works fine in all other contexts on the script. So i'm not too sure if it's the print function. but i'll look into it. – Towhee

Answer 4

Here are 2 things i want you to try for debugging. At least visually i cannot see something wrong in yout code, unless someone see it.

first does your function work when you call it by itself? not inside the set Timeout

var runAfterPause=function() {
  print("got here..."); 
  print(document.getElementById('some_id').innerHTML);
}

// call function by it self
runAfterPause();

2nd try running it as an anonymous function inside your setTimeout;

var delay = setTimeout(function () {
   print("got here..."); // never gets called
   print(document.getElementById('some_id').innerHTML);
},3000);

this should help you debug your code and see where the error is.

Brooklet