How to make Transfer-Encoding: chunked work?

[Eric Fong]

Hi

I have a stupid question. I have following code and hoping the data
chunks render one by one.
But my chrome wait 3 second and render everything all in one. Anyway
to make it works?

var http = require('http');
http.createServer(function (request, response) {
response.writeHead(200, {
'Content-Type': 'text/plain',
'Transfer-Encoding': 'chunked'
});
setTimeout(function(){
response.write('25\n');
response.write('This is the data in the first chunk\n\n');
}, 1000);
setTimeout(function(){
response.write('1C\n');
response.write('and this is the second one\n\n');
}, 2000);
setTimeout(function(){
response.end('0');
}, 3000);
}).listen(8124);
console.log('Server running at http://127.0.0.1:8124/');

Thanks

[Terry Riegel]

What if instead of using chinned encoding you just sent discrete HTML elements, like...

<div>line1</div>
wait 1 second
<div>line 2</div>
etc...

I doubt if you be able to change the behavior of Chrome.

Terry

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[Matthew]

What does your client-side JS look like? If you're using the
onreadystatechange event to update the DOM then that's the problem.

From the 2006 W3C XHR draft (removed from the latest draft for some
reason):

onreadystatechange... represents a function that must be invoked when
readyState changes value. The function MAY be invoked multiple times
when readyState is 3 (Receiving). Its initial value must be null.

That MAY is crucial - it means that to adhere to spec, a browser
doesn't have to fire the onreadystatechange event multiple times for
the same readystate. So while some browsers will fire the event each
time a new chunk is received, others will fire it for the first chunk
and then only again when the data transfer has completed, when
readystate is 4.

I think that the only browser that fires the onreadystatechange event
multiple times for the same readystate (3) is Firefox.

[Joe Shaw]

Hi,

On Jul 18, 10:46 am, Eric Fong <eri...@gmail.com> wrote:
> I have a stupid question. I have following code and hoping the data
> chunks render one by one.

I'm not sure it matters, but your chunks don't conform to the
requirements of the chunked TE in RFC 2616. Namely, the chunk size
and chunks are supposed to be terminated with a CRLF (\r\n). More
details here:

http://en.wikipedia.org/wiki/Chunked_transfer_encoding#Format

>   setTimeout(function(){
>           response.write('25\n');

This should be terminated with a CRLF (\r\n)

>           response.write('This is the data in the first chunk\n\n');

This too.

>   }, 1000);
>   setTimeout(function(){
>           response.write('1C\n');

Ditto.

>           response.write('and this is the second one\n\n');

Are you noticing a pattern? :)

>   }, 2000);
>   setTimeout(function(){
>           response.end('0');

Ditto. I suspect this is probably the most important one that you're
missing.

>   }, 3000);}).listen(8124);
>
> console.log('Server running athttp://127.0.0.1:8124/');

Hope this helps,

Joe

[Mikeal Rogers]

node already does chunked encoding for you.

If you don't return a content-length in the headers you sent your writes will be chunked by default. You shouldn't need to worry about any of this.

-Mikeal

[Cagdas Tulek]

Does node also support loading a file from the middle, then?

[Mikeal Rogers]

I don't know what you mean? Can you explain?

[Eric Fong]

Hi

node is already chunked for me ?
But my browser render the code all in once?
Is the chunked and progressive loading only work in Ajax ?

Eric

> > nodejs+un...@googlegroups.com<nodejs%2Bunsu...@googlegroups.com>
> > .

[Mikeal Rogers]

The browser will render chunked and fixed length iteratively as it comes off the socket. Chunked encoding won't effect that.

Also, the chunked encoding overhead is parsed out in ajax so you'll never see it directly.

-Mikeal

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[Cagdas Tulek]

In HTTP/1.1, the browser can also ask for a specific part of a file by "Content-Range". (See 14.16 Content-Range)

[Mikeal Rogers]

But, not all servers support this.

[mscdex]

On Jul 18, 10:18 pm, Cagdas Tulek <ctu...@gmail.com> wrote:
> Does node also support loading a file from the middle, then?

You can read a file at any position you want. Take a look at fs.read()
here: http://nodejs.org/api.html#fs-read-141

[Cagdas Tulek]

Sure, I was just curious.

[Timothy Caswell]

I would love to implement this as part of the staticProvider layer in Connect. 

[Alexey Petrushin]

Does anyone managed to get it work in Chrome?

It works with curl, but it doesn't work with Chrome.