[Gambas-user] App idle with long loops

[Fabien Bodard]

2016-10-08 23:54 GMT+02:00 Demosthenes Koptsis <demosthenesk at ...626...>:
> On 8/10/2016 19:09 μμ, Tobias Boege wrote:
>> On Sat, 08 Oct 2016, Demosthenes Koptsis wrote:
>>> Hello,
>>>
>>> i have very long (time consuming) For loops and my app is frozen until
>>> loop is finished.
>>>
>>> for example i wget urls with a custom Sub which Shell("wgetURLS.sh") To
>>> sOUTPUT
>>>
>>>     'get urls
>>>     For i = 0 To iDepth
>>>       wgetURLS(i * 10)
>>>     Next
>>>
>>> Public Sub wgetURLS(iStart As Integer)
>>> .....
>>>
>>> Shell("wgetURLS.sh") To sOUTPUT
>>>
>>> .....
>>>
>>> --------------
>>>
>>> Is there possible to set the gui idle and the same time run For...loops?
>>>
>> If you only want to refresh the GUI (e.g. if your For loops update a
>> ProgressBar on your form and you want to update the value of that bar
>> during the loop), then Wait [1] is sufficient.
>>
>> If you want the GUI to be fully operatable while your loops run in the
>> background, you have to use a background Task [2]. As Gambas is single-
>> threaded, Tasks are implemented as external processes which execute one
>> of your classes. This limits the things you can do with Tasks (you cannot
>> directly modify the main program, for example, but have to send data and
>> status reports through a pipe from your Task to the main process and
>> interpret them there). However, if all you want is loading some files via
>> wget, that should not be a problem.
>>
>> Of course, there is also the gb.net.curl component which can download files
>> asynchronously. If you can use that (which depends on what you want to do),
>> you should.
>>
>> And as a fourth option, looking further into your code: if you want to
>> execute shell scripts in a For loop, then don't use the Shell-To syntax
>> but create a Process object instead and accumulate its output in Read
>> events. The event loop will take care of everything and the GUI will be
>> usable without any extra effort on your side.
>>
>> Finding the best solution depends, who would have thought, on what you want
>> to do *specifically*. Tasks are the most general and most cumbersome option.
for my feel, i prefers using multiple process objects or if i use
httpClient multiple client.

There is an exemple of use in the gb.map source (tilemap) of multiple
http server client
>>
>> Regards,
>> Tobi
>>
>> [1] http://gambaswiki.org/wiki/lang/wait
>> [2] http://gambaswiki.org/wiki/comp/gb/task
>>
> Thanks very much for the details.
>
> Regards,
>
> Dim
>
>
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-- 
Fabien Bodard