| Re: Output status during processing [message #179531 is a reply to message #179530] |
Mon, 05 November 2012 01:21   |
Jerry Stuckle
Messages: 2598
Registered: September 2010
Karma:
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Senior Member |
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On 11/4/2012 4:52 PM, Scott Johnson wrote:
> On 11/4/2012 1:28 PM, M. Strobel wrote:
>> Am 04.11.2012 20:23, schrieb Scott Johnson:
>>> Hello
>>>
>>> I hate to come here with a question without any tried code but I
>>> really do not even
>>> know where to start, I have never attempted this before without a net.
>>>
>>> What I would like to do is provide an output to the browser during a
>>> long processing
>>> term.
>>>
>>> Exactly what I am doing is this.
>>>
>>> I am loading a csv file to update inventory.
>>>
>>> During this process I am flushing the current Table and then loading
>>> the new and then
>>> comparing the inventory table to a product table and would like to
>>> provide status of
>>> where we are in the process what items matched and changed and so
>>> forth in real time.
>>>
>>> I have done some similar tasks in JS but with minimal steps in the
>>> processing then
>>> what I am trying to accomplish.
>>>
>>> I did some binging and found that it may have to do with output
>>> buffering but nothing
>>> particular to my situation. (as far as I could find)
>>>
>>> If this is possible could someone point me in the right direction and
>>> I will do the
>>> leg work.
>>
>> Are you starting your long running job in the browser? Not good, the
>> whole setup is
>> designed for request-response, and not long running jobs.
>>
>> I would try to design the long running update-compare job as a
>> separate process,
>> writing status or progress information to a file/a db table. Then you
>> have a
>> corresponding script you call in your browser, showing you status and
>> progress. This
>> could be done with whole page refreshs or with ajax.
>>
>> /Str.
>>
>
> Ok that makes makes sense.
>
> And yes it was started in the browser on a file upload from a form field.
>
> I could use AJAX to load the file and then process it in the background
> sending status points as it goes through AJAX.
>
> I have done this is the past just not for so many steps to perform.
>
> The more I read about the PHP buffer functions, I could not find a way
> that would periodically send text without a header issue.
>
> Guess why they have different tools for the different needs.
>
> Thanks Str.
>
> Scotty
>
>
Nope, but it has nothing to do with php. HTTP is a request/response
protocol; the client sends a request and expects a response within the
time specified by the browser's timeout value.
But then this causes a problem also, because PHP has a buffer (for
efficiency), the server has a buffer (also for efficiency), routers
along the way may have buffers (again, for efficiency), and the client's
system may have a buffer (hmmm... efficiency?) and finally the browser
may have a buffer.
The bottom line is - the HTTP protocol is pretty much useless for
long-running tasks. The time it takes to send data to the browser is
dependent on a lot of things, and the browser's timeout values are
independent of anything the server can control.
If you need such processing, I suggest you look into other methods of
communications. Java applets, for instance, can work with non-http
protocols.
--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstucklex(at)attglobal(dot)net
==================
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